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Thu, 3 December 2009
Direct download: AAGG_sky_tour_Dec_2009.mp3
Category: Sky Tours
-- posted at: 2:48 PM |
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Wed, 2 December 2009
Monthly notes are up! Audio will be up tomorrow!
Category: Sky Tours
-- posted at: 7:26 AM |
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Wed, 2 December 2009
Astronomy a Go Go! December Sky Tour
This tool displays the approximate Moon phases for a
given month(images are close approximations). For official phase times and dates
for this month and past months are available from the U.S. Naval
Observatory.
Astronomical Online
Glossary
Download this month's sky map!Skymaps.com is our favorite monthly
skymap provider. Download either the Northern hemisphere, Equatorial, or
Southern Hemisphere sky map so you can follow along with our viewing
sessions.
Creator: Kym Thalassoudis
Southern Hemisphere Additional InformationAs Astronomy a Go Go! finds
its home in the higher Northern latitudes those of you who live south of the
equator will benefit from these two Southern Hemisphere sites: Royal
Astronomical Society of New Zealand's Southern Hemisphere Calendar RASNZ site (absolutely
outstanding) and
Southern Sky Watch.
December Morning Planets
(click images to enlarge)
December morning sky
December evening sky
December late night
- Mercury- the "evening star" through December much better viewing the
further South your viewing site -0.5 mag (1st) to -0.4 mag (21st)
- Venus- too close to the Sun for reliable viewing -3.8 mag (1st) to
-3.8 mag (21st)
- Mars- in Western Leo (between Cancer and Leo) look very late evening
or very early morning. Mars will slowly creep towards the 'mouth' of the Lion
all month -0.1 mag (1st) to -0.5 mag (21st)
- Jupiter- in Capricorn in the early evening. Bright in the SW for a
few hours after Sunset look for Mercury, Jupiter and the Moon together on the
18-19th. -2.3 mag (1st) to -2.2 mag (21st)
- Saturn- in Virgo all month rising after midnight and about 4 hours
after Mars 1.1 mag (1st) to 1.1 mag (21st)
- Uranus- Hovering just inside the Aquarius side of the Aquarius/Pisces
border crossing back into Pisces in mid-January 5.7 mag (1st) to 5.7 mag (21st)
- Neptune- In Capricorn all month. Jupiter slides eastward south of
Neptune with a close, moon-less encounter on Dec. 24-25 7.9 mag (1st) to 7.9 mag
(21st)
- Ceresand Eta - Finder chart
from the New Zealand RAS (RASNZ) great charts! Northern Hemisphere observers
this time you get to flip the chart or stand on your head!
Vesta chart
temporarily missing...use this
one until site is corrected
Key Dates for December 2009
Days and Times in UT: (help with
time)
Observations are for 8 pm for Northern Hemisphere and 10 pm for the
Southern Hemisphere.
Today's sunrise
and sunset times or plan ahead using the US Naval Observatory
Website
Occultation information can be found at the IOTA website!
Astronomical Highlights - December 2009
| 1 |
- Algol at minimum (6:15 UT) Moon 0.03 deg S of Pleiades (M45) |
| 2 |
- Uranus stationary |
| 3 |
- Jovian moon phenomena: Io occults Europa (2:08 UT) Transit of the Great
Red Spot 10 minutes later |
|
- Full Moon (7:30 UT) |
| 4 |
- Moon at perigee (363479 km) |
| 6 |
- Moon near Beehive Cluster (M44) |
| 7 |
- Mercury at greatest heliocentric lat. South |
|
- Mars 5 deg N of the Moon |
| 9 |
- Last Quarter (0:13 UT) |
| 10 |
- Saturn 8 deg N of Moon |
| 14 |
- Geminid meteor
shower peak, with little Moon and an early rising of Gemini should make this a
favorable shower. Expect up to 80 bright, medium-speed meteors per hour.
|
| 16 |
- New Moon (12:02 UT) |
| 18 |
- Mercury 1.4 deg S of Moon and greatest elongation East |
| 20 |
- Venus in descending mode |
|
- Jupiter 0.6 deg S of Neptune |
|
- Moon at apogee (405731 km) |
| 21 |
- Double shadow transit on Jupiter (1:34 UT) |
|
- Jupiter 4 deg S of Moon |
|
- Mars stationary |
|
- Solstice (17:47 UT) The Sun reaches its furtherest point South of the
Celestial Equator. Summer for the Southern Hemisphere, Winter for the Northern.
A description can be found
here. |
| 22 |
- Jovian moon phenomena: Europa occults Io (2:48 UT) Transit of the Great
Red Spot (3:07 UT) |
| 24 |
- First Quarter (17:36 UT) |
|
- Pluto in conjunction with the Sun |
| 26 |
- Mercury at ascending node |
| 31 |
- Mercury at perihelion |
|
- Full Moon a "Blue Moon" |
|
- Partial lunar eclipse penumbral grazing the umbra visible through most of
Europe, Africa, Asia, Australia |
Date information courtesy of: RASC Observer's Handbook, Skymaps.com,
Astronomical Calendar 2009, CalSky, Skymaps.com. sunrise and sunset times
for your home*
Comparative lengths of
day and night
This will be a fairly easy month on the tour. We will view two small, but
bright globular clusters, two open star clusters, and the grandest galaxy in the
sky along with it's two companions. All of these objects are possible to find in
binoculars, most are fairly easy.
- M2
- This is a small, bright globular cluster in Aquarius. To find it in
binoculars look for a fuzzy star in a star poor field. A low power telescope
field will show a round fuzzy patch, brighter in the center and fading to the
edge, in a field with no other bright objects.
- M15
- This globular cluster in Pegasus is very similar to M2 in size and
brightness, except it is surrounded by several bright stars. Fairly easy to find
in binoculars but the best view is through a telescope at medium to high power.
- M29
- This galactic cluster is a small, sparse group of stars in Cygnus. It
appears as a small fuzzy patch amongst a rich star field in binoculars. A
telescope will easily resolve the members of this cluster. The shape of the
cluster reminds me of the Pleiades as viewed through binoculars.
- M39
- Dark skies will allow this large, bright cluster in Cygnus to be seen with
the naked eye as a hazy patch of light. Binoculars easily resolve this cluster
into it's bright and widely scattered members, and provide a better view than
can be seen with most telescopes.
- M31
- This is the famous Andromeda Galaxy, our closest galactic neighbor, and the
largest, brightest galaxy to be seen in the northern sky. The ability to see M31
with the naked eye provides a good test of the darkness of your skies. M31 is so
large that binoculars provide the best view, allowing the entire galaxy to be
seen in one field of view. Look for an elongated patch of light, with a bright,
round central core.
- M32
- This is an elliptical companion galaxy to M31. Through a telescope look for
a slightly oval ball of fuzz in the same low power field as the core of M31. M32
is very possible to find in binoculars as a star like point of light.
- M110
- Another elliptical companion galaxy to M31, lying on the opposite side of
the core as M32. Through a telescope look for a large, oval patch of light.
Although M110 is as bright as M32 it is much larger and thus has a lower surface
brightness making it a difficult object in light polluted skies. M110 is a very
difficult binocular object requiring dark transparent skies, and trained eyes to
have a chance at finding it.
From the Astronomical
Connection and the Moncton Center in Canada
From the Tony
Cecce, Corning, NY - Twelve Month Tour of The Messier Catalog
Comets for December 2009
More comet information at Seiichi Yoshida's comet
website. Also checkout Gary Kronk's comet
and meteor pages Skyhound Comet pages
Historical and Current Events...Did you know?
Mark has developed his own website so
let's all trot on over and see the pages of wonderful history he has for us this
month!
Help us out by leaving a donation in the ol' PayPal hator write us a
favorable review in iTunes of Podcast Pickle or iPodder!
Music Scottish Guitar
Quartet -"Romance Within You"
Black
Lab- "See the Sun"
Anne
Farnsworth- "Saturday Morning"
Great Astronomy Activities!
Citizen Sky
For those in Northern Hemisphere, Capella, the "She Goat" in Aurigae, is
circumpolar. At my 47 deg North, Capella disappears behind the tree line, and
into the light polluted horizon, but she pops up in a few hours and is easy to
find. Also easy to find are epsilon Aurigae (al Maaz the Billy Goat) and "The
Kids" which make a small, long, triangle of stars just to the Southwest of
Capella.
For the next 21 months Epsilon Aurigae, usually the brightest of the trio,
will start behaving quite differently than it has for the past 27 years. Epsilon
Aurigae is a type of variable star called an eclipsing binary. Epsilon Aurigae
and some unknown dark partner, rotate around a common center of mass and every
27 years that dark companion eclipses the giant F-type star. August marks the
anticipated beginning for that eclipse which will last for 714 days, dimming
from 3.0 mag to about half of its brightness.
So why am I calling this a great astronomy activity? Epsilon Aurigae has some
definite quirks and more eyes are needed to help scientist figure out what
Epsilon Aurigae's invisible partner really is! We need help...WE NEED YOU!!
Anyone can participate; we need people to observe epsilon Aurigae, folks to look
at the data for quirks, patterns, or voids, artist to help present the data to
the public, friends willing to get the word out to others! To find out more
visit:
Earth's major motions for 2009
| Perihelion |
|
Jan 4 15(UT) |
| First Cross Quarter Day |
|
Feb 2-6 |
| Equinox |
|
Mar 20 11:44(UT) |
| Second Cross Quarter Day |
|
May 4-7 |
| Solstice |
|
June 21 05:45(UT) |
| Aphelion |
|
July 4 02h (UT) |
| Third Cross Quarter Day |
|
Aug 5-8 |
| Equinox |
|
Sept 22 21:18(UT) |
| Fourth Cross Quarter Day |
|
Nov 5-8 |
| Solstice |
|
Dec 21 17:47(UT) |
Planet Positions for 2009
| 2009 |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
| Venus |
Sgr |
Cap |
Aqr |
Psc |
Tau |
Gem |
Cnc |
Vir |
Vir |
Sco |
Sgr |
Cap |
| Mars |
Sgr |
Cap |
Aqr |
Psc |
Psc |
Ari |
Tau |
Tau |
Gem |
Cnc |
Cnc |
Leo |
| Jupiter |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
| Saturn |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Vir |
Vir |
Vir |
Vir |
Interesting Planet Pairing for 2009
- December 31, 2008 - Jupiter and Mercury - After sunset a
little more than one degree apart in Sagittarius. Pull out the binos and
telescopes because Mercury will be a mere 15 arcminutes from the globular
cluster M75. All three will be together in one field of view in most home
binoculars.
- January 22nd - Venus and Uranus - After sunset 1.3 degrees
apart a few days later on the 29th they are joined by a waxing crescent moon.
- February 23rd - Jupiter, Mars and Mercury - In the early
morning sky just before sunrise the trio are in a space about 2 degrees wide.
Binoculars will be helpful but beware the quickly rising Sun. The Moon, almost
invisible, will be between Mars and the Sun.
- March 23rd - Mars, Moon, Neptune, and Jupiter - Makes a nice
line-up in the morning sky with Neptune just off the tip of the waning crescent
moon.
- April 21st - Venus, Mars, Uranus, waning crescent Moon, Neptune
and Jupiter - all in the pre-dawn sky together. First the right triangle of
Venus, Mars, and Uranus followed by the waning crescent Moon and then finally by
Neptune and Jupiter. Mars will be a faint 1.41 mag so binoculars will be
helpful. The next day, possible occultation of Venus by the Moon. Check the IOTA
website for occultations in your area.
- May 25th - Jupiter and Neptune - Jupiter is less than 1/2
degree South of Neptune in the morning sky. If you have ever had problems
finding Neptune this would be a good time to try, between now and June.
- June 19th - Venus and Mars - In the pre-dawn sky just south of
a waning crescent Moon. Closer to the Sun is Mercury and the Pleiades.
- August 17th - Saturn and Mercury - Very close to the Sun low
in the evening sky. Much better view for Southern viewers.
- September 3rd UT 4:43 - Jupiter hides its Galilean moons. Not
until 2019 will all of Jupiter's Galilean moons orbit in such a way.
- September 4th - Saturn - Not exactly a pairing but the Earth
will cross the plane of the rings from south to north making the rings invisible
- October 16th - Mercury, Venus, and Saturn - All lined up in
the pre-dawn sky close to the horizon. A faint waning crescent is just south of
the trio.
- December 24th - Jupiter and Neptune - Just after sunset
Jupiter and Neptune sit side-by-side just north of delta Capricornus and east of
the "42,44,45 Cap Wall"
Phases of the Moon 2009
(click to enlarge)
Universal Time
NEW MOON FIRST QUARTER FULL MOON LAST QUARTER
d h m d h m d h m d h m
JAN. 4 11 56 JAN. 11 3 27 JAN. 18 2 46
JAN. 26 7 55 FEB. 2 23 13 FEB. 9 14 49 FEB. 16 21 37
FEB. 25 1 35 MAR. 4 7 46 MAR. 11 2 38 MAR. 18 17 47
MAR. 26 16 06 APR. 2 14 34 APR. 9 14 56 APR. 17 13 36
APR. 25 3 23 MAY 1 20 44 MAY 9 4 01 MAY 17 7 26
MAY 24 12 11 MAY 31 3 22 JUNE 7 18 12 JUNE 15 22 15
JUNE 22 19 35 JUNE 29 11 28 JULY 7 9 21 JULY 15 9 53
JULY 22 2 35 JULY 28 22 00 AUG. 6 0 55 AUG. 13 18 55
AUG. 20 10 02 AUG. 27 11 42 SEPT. 4 16 03 SEPT. 12 2 16
SEPT. 18 18 44 SEPT. 26 4 50 OCT. 4 6 10 OCT. 11 8 56
OCT. 18 5 33 OCT. 26 0 42 NOV. 2 19 14 NOV. 9 15 56
NOV. 16 19 14 NOV. 24 21 39 DEC. 2 7 30 DEC. 9 0 13
DEC. 16 12 02 DEC. 24 17 36 DEC. 31 19 13
Eclipses for 2009
January 26 - Annular Solar Eclipse ( see map,
times, and animation!): The first
solar eclipse of 2009 occurs at the Moon's ascending node in western
Capricornus. An annular eclipse will be visible from a wide track that traverses
the Indian Ocean and western Indonesia. A partial eclipse will be seen within
the much larger path of the Moon's penumbral shadow, which includes the southern
third of Africa, Madagascar, Australia except Tasmania, southeast India,
Southeast Asia and Indonesia.
February 09 - Penumbral Lunar Eclipse ( see map,
times): The first lunar eclipse of 2009 is one of four such events during
the year. The first three eclipses are penumbral while the last (on Dec. 31) is
partial. The Feb 09 event is the deepest penumbral eclipse of the year with a
penumbral magnitude of 0.899. It will be easily visible to the naked eye as a
dusky shading in the northern half of the Moon. The times of the major phases
are listed below.
July 07 - Penumbral Lunar Eclipse ( see map,
times.): July's penumbral eclipse is only of academic interest since the
magnitude is just 0.156. Although the Moon will be above the horizon from most
of Canada, the eclipse is so minor as to be completely invisible to the naked
eye.
July 21-22 - Total Solar Eclipse ( see map,
times, and animation!): To make up
for the anemic lunar eclipse earlier in the month, a major total eclipse of the
Sun occurs two weeks later. The path of the Moon's umbral shadow extends across
India, China, a handful of Japanese islands and the South Pacific Ocean (Espenak
and Anderson, 2008). A partial eclipse is seen within the much broader path of
the Moon's penumbral shadow, which includes most of eastern Asia, Indonesia, and
the Pacific Ocean.
August 05-06 - Penumbral Lunar Eclipse ( see map,
times): A shallow penumbral eclipse occurs 15 days after the total solar
eclipse. Since its magnitude is only 0.402, it will not be visible to the naked
eye.
December 31 - Penumbral Lunar Eclipse ( see map,
times): The last eclipse of 2009 occurs on New Year's Eve. This minor
partial lunar eclipse takes place in Gemini, and is visible primarily from the
Eastern Hemisphere (Figure 8). Greatest eclipse takes place at 19:23 UT when the
eclipse magnitude will reach 0.0763.
Eclipse information from: NASA Eclipse
Homepage, Eclipses
Online (HM Nautical Almanac Office, UK in coordination with the U.S. Naval Observatory)
| Shower |
Activity Period |
Maximum |
Radiant |
Velocity |
r |
ZHR |
Class |
Moon |
| |
|
Date |
S. L. |
R.A. |
Dec. |
km/s |
|
|
|
|
| Antihelion Source (ANT) |
Dec 14-Sep 07 |
- |
- |
- |
- |
30 |
3.0 |
3 |
II |
- |
| Quadrantids (QUA) |
Dec 26-Jan 13 |
Jan 03 |
283°16 |
15:20 |
+49° |
42 |
2.1 |
120 |
I |
6 |
| Alpha Centaurids (ACE) |
Jan 28-Feb 21 |
Feb 07 |
319°2 |
14:00 |
-59° |
56 |
2.0 |
5 |
II |
12 |
| Delta Leonids (DLE) |
Feb 15-Mar 10 |
Feb 25 |
336° |
11:12 |
+16° |
23 |
3.0 |
2 |
II |
0 |
| Gamma Normids (GNO) |
Feb 25-Mar 22 |
Mar 13 |
353° |
16:36 |
-51° |
56 |
2.4 |
4 |
II |
16 |
| Lyrids (LYR) |
Apr 16-Apr 27 |
Apr 23 |
033° |
18:12 |
+33° |
46 |
2.1 |
18 |
I |
27 |
| Pi Puppids (PPU) |
Apr 15-Apr 28 |
Apr 23 |
033°5 |
07:20 |
-45° |
18 |
2.0 |
var |
III |
27 |
| Eta Aquarids (ETA) |
Apr 27-May 23 |
May 07 |
047° |
22:36 |
-01° |
68 |
2.4 |
60 |
I |
12 |
| Eta Lyrids (ELY) |
May 06-May 14 |
May 10 |
050° |
19:22 |
+43° |
43 |
3.0 |
3 |
II |
15 |
| June Bootids (JBO) |
Jun 22-Jul 02 |
Jun 27 |
095°7 |
14:56 |
+48° |
18 |
2.2 |
var |
III |
5 |
| Piscis Austrinids (PAU) |
Jul 15-Aug 10 |
Jul 28 |
125° |
22:44 |
-30° |
35 |
3.2 |
5 |
II |
7 |
| Alpha Capricornids (CAP) |
Jul 12-Aug 08 |
Jul 28 |
125° |
20:20 |
-10° |
24 |
2.5 |
4 |
II |
7 |
| Delta Aquarids (SDA) |
Jul 21-Aug 30 |
Jul 30 |
127° |
22:42 |
-17° |
43 |
3.2 |
20 |
I |
9 |
| Perseids (PER) |
Jul 13-Aug 26 |
Aug 12 |
140° |
03:12 |
+58° |
59 |
2.6 |
100 |
I |
20 |
| Kappa Cygnids (KCG) |
Aug 03-Aug 25 |
Aug 17 |
145° |
19:04 |
+59° |
25 |
3.0 |
3 |
II |
25 |
| Alpha Aurigids (AUR) |
Aug 28-Sep 03 |
Sep 01 |
158°6 |
06:06 |
+39° |
65 |
2.6 |
7 |
II |
11 |
| September Perseids (SPR) |
Sep 06-Sep 13 |
Sep 10 |
168° |
03:12 |
+40° |
65 |
2.9 |
5 |
II |
19 |
| Delta Aurigids (DAU) |
Sep 18-Oct 10 |
Sep 29 |
186° |
05:52 |
+49° |
64 |
2.9 |
2 |
II |
13 |
| Draconids (GIA) |
Oct 06-Oct 10 |
Oct 08 |
195°4 |
17:28 |
+54° |
20 |
2.6 |
var |
III |
18 |
| Southern Taurids (STA) |
Sep 18-Nov 26 |
Oct 11 |
198° |
02:18 |
+09° |
29 |
2.3 |
5 |
II |
21 |
| Epsilon Geminids (EGE) |
Oct 18-Oct 21 |
Oct 20 |
207° |
06:48 |
+28° |
71 |
3.0 |
2 |
II |
2 |
| Orionids (ORI) |
Sep 28-Nov 10 |
Oct 21 |
208° |
06:22 |
+16° |
68 |
2.5 |
23 |
I |
3 |
| Leo Minorids (LMI) |
Oct 17-Oct 27 |
Oct 23 |
209° |
10:40 |
+37° |
61 |
2.7 |
2 |
II |
4 |
| Northern Taurids (NTA) |
Oct 20-Nov 29 |
Nov 13 |
231° |
03:52 |
+22° |
29 |
2.3 |
5 |
II |
25 |
| Leonids (LEO) |
Nov 07-Nov 28 |
Nov 18 |
236° |
10:16 |
+22° |
71 |
2.5 |
var |
III |
1 |
| Alpha Monocerotids (AMO) |
Nov 15-Nov 25 |
Nov 21 |
239°32 |
07:48 |
+01° |
65 |
2.4 |
var |
III |
4 |
| Dec Phoenicids (PHO) |
Nov 28-Dec 09 |
Dec 06 |
254°25 |
01:12 |
-53° |
18 |
2.8 |
var |
III |
18 |
| Puppid/Velids (PUP) |
Dec 01-Dec 15 |
Dec 07 |
255° |
08:12 |
-45° |
40 |
2.9 |
10 |
I |
19 |
| Monocerotids (MON) |
Dec 06-Dec 20 |
Dec 07 |
255° |
06:32 |
+09° |
41 |
3.0 |
2 |
II |
10 |
| Sigma Hydrids (HYD) |
Nov 22-Dec 23 |
Dec 09 |
257° |
08:24 |
+03° |
60 |
3.0 |
3 |
II |
21 |
| Geminids (GEM) |
Dec 05-Dec 19 |
Dec 14 |
262°2 |
07:36 |
+32° |
35 |
2.6 |
120 |
I |
26 |
| Coma Berenicids (COM) |
Dec 10-Jan 25 |
Dec 19 |
268° |
11:40 |
+25° |
64 |
3.0 |
5 |
II |
3 |
| Ursids (URS) |
Dec 16-Dec 25 |
Dec 22 |
270°7 |
14:34 |
+75° |
32 |
3.0 |
10 |
I |
5 |
Information and Table Template Courtesy The American Meteor Society, International Meteor Organization, and Meteors Online.
Shower: named for the constellation or closest star within a
constellation where the radiant is located at maximum activity.
Activity Period: the dates when the ZHR (Zenith Hourly Rates) are
equal to or greater than one.
Maximum: the date on which the maximum activity is expected to occur.
S.L.: the equivalent solar longitude of the date of maximum
activity. Solar longitude is measured in degrees (0-359) with 0 occurring at the
exact moment of the spring equinox, 90 at the summer solstice, 180 at the
autumnal equinox, and 270 at the winter solstice.
Radiant: the area in the sky where shower meteors seem to appear from.
This position is given in right ascension (celestial longitude) and
declination (celestial latitude).
Velocity: the velocity at which shower meteors strike the Earth's
atmosphere. The velocity depends on the angle meteoroids (meteors in space)
intersect the Earth. Meteoroids orbiting in the opposite direction of the Earth
and striking the atmosphere head-on are much faster than those orbiting in the
same direction as the Earth. This velocity is measured in kilometers per second.
r: The Population Index, An estimate of the ratio of the number
of meteors in subsequent magnitude classes. Simply stated: the lower the "r"
value, the resulting overall mean magnitude of each shower will be brighter. "r"
usually ranges from 2.0 (bright) to 3.5 (faint).
ZHR: Zenith Hourly Rate, the average maximum number of shower
meteors visible per hour if the radiant is located exactly overhead and the
limiting magnitude equals +6.5. Actual counts rarely reach this figure as the
zenith angle of the radiant is usually less and the limiting magnitude is
usually lower. ZHR is a useful tool when comparing the actual observed rates
between individual observers as it sets observing conditions for all to the same
standards.
Class: A scale developed by Robert Lunsford to group meteor showers by
their intensity:
Class I: the strongest annual showers with ZHR's normally ten or
better.
Class II: reliable minor showers with ZHR's normally three or better.
Class III: showers with widely variable rates. They may be strong one
year and totally inactive the next.
Class IV: weak minor showers with ZHR's rarely exceeding three. The
study of these showers is best left to experienced observers who use plotting
and angular velocity estimates to determine shower association. Observers with
less experience are urged to limit their shower associations to showers with a
rating of I to III. These showers are also good targets for video and
photographic work.
Moon: the age of the moon in days where 0 is new, 7 is first quarter,
14 is full, and 21 is last quarter. Meteor activity is best seen in the absence
of moonlight so showers reaching maximum activity when the moon is less than 10
days old or more than 25 are much more favorably observed than those situated
closer to the full moon.
Information from the "Observer's Handbook 2009" RASC
Category: Sky Tours
-- posted at: 7:20 AM |
|
Fri, 4 September 2009
Astronomy a Go Go! September Sky Tour
This tool displays the approximate Moon phases for a
given month(images are close approximations). For official phase times and dates
for this month and past months are available from the U.S. Naval
Observatory.
Astronomical Online
Glossary
Download this month's sky map!Skymaps.com is our favorite monthly
skymap provider. Download either the Northern hemisphere, Equatorial, or
Southern Hemisphere sky map so you can follow along with our viewing
sessions.
Creator: Kym Thalassoudis
Southern Hemisphere Additional InformationAs Astronomy a Go Go! finds
its home in the higher Northern latitudes those of you who live south of the
equator will benefit from these two Southern Hemisphere sites: Royal
Astronomical Society of New Zealand's Southern Hemisphere Calendar RASNZ site (absolutely
outstanding) and
Southern Sky Watch.
Great Astronomy Activities!
Citizen Sky
For those in Northern Hemisphere, Capella, the "She Goat" in Aurigae, is
circumpolar. At my 47 deg North, Capella disappears behind the tree line, and
into the light polluted horizon, but she pops up in a few hours and is easy to
find. Also easy to find are epsilon Aurigae (al Maaz the Billy Goat) and "The
Kids" which make a small, long, triangle of stars just to the Southwest of
Capella.
For the next 21 months Epsilon Aurigae, usually the brightest of the trio,
will start behaving quite differently than it has for the past 27 years. Epsilon
Aurigae is a type of variable star called an eclipsing binary. Epsilon Aurigae
and some unknown dark partner, rotate around a common center of mass and every
27 years that dark companion eclipses the giant F-type star. August marks the
anticipated beginning for that eclipse which will last for 714 days, dimming
from 3.0 mag to about half of its brightness.
So why am I calling this a great astronomy activity? Epsilon Aurigae has some
definite quirks and more eyes are needed to help scientist figure out what
Epsilon Aurigae's invisible partner really is! We need help...WE NEED YOU!!
Anyone can participate; we need people to observe epsilon Aurigae, folks to look
at the data for quirks, patterns, or voids, artist to help present the data to
the public, friends willing to get the word out to others! To find out more
visit:
NASA's MicroObservatories
Another fantastic project, that AAGG is supporting all through the month of
September, it the "Capture the Colorful Cosmos" project using the NASA
MicroObservatories. This project gives you the opportunity to direct a robotic
telescope and then manipulate the resulting images!
I had the opportunity to help school age kids, and some kid-like adults,
through the project at the Tacoma Astronomical Society's annual Astronomy Fair
in August and we had a wonderful time! They were using filter, shifting and
stacking images, and turning out images like the pros!
 
Sweet and innocent "A", and the postcard of M51
he created (Blasters of Death -- go figure), and his sister's Orion composite
image (ahhhhhh!)
LCROSS ImpactAstronomers, amateur and professional a like, who
have access to dark skies and large aperture scopes are encouraged to
participate in imaging and video taping the impact of the Centaur impactor and
the LCROSS satellite with the Moon. The primary objective of the Lunar Crater
Observation and Sensing Satellite (LCROSS) is to confirm the presence or absence
of water ice in the Moon's polar region. But the amazing bit will be the five
body choreography between the Moon, the Centaur rocket/impactor, the Shepherding
craft/research vessel/impactor, and LRO (who was launched with LCROSS) who will
also observe the action, and YOU, on Earth!
I mean... what other impactor mission has its own music
video!
More information can be found at the LCROSS Citizen Observing
Campaign Site.
Images courtesy of: New Mexico State
Univ
Planets for September 2009September Morning
Planets
(click images to enlarge)
Beginning of the month
End of the month
- Mercury- Starts September headed for the Sun in the early evening
sky, best observed by lower and southern latitudes. By the end of the month
Mercury will join Venus, Mars, and Saturn in the morning sky. 0.5 mag (1st) to
5.5 mag (21st)
- Venus- Beautiful in the morning sky and is heading eastward towards
Regulus. Venus will be half a degree north of Regulus on the 20th of the month
as she heads back towards the Sun. She will pair up with Mercury and Saturn in
the early October sky so make sure you spend some time pre-sunrise time around
the 5th of October with Venus and Saturn making a Mercury breakfast sandwich!
-3.8 mag (1st) to -3.8 mag (21st)
- Mars- Spends the month in Gemini so you'll need to get up early for
this one too! 1.00 (1st) to 0.9 mag (21st)
- Jupiter- AAGG missed Jupiter's vanishing moons due to bad weather but
John Chumack, of The Chumack Observatories, captured the event and has a movie
posted at his site! -2.8 mag (1st) to -2.7 mag (21st)
- Saturn- In conjunction with the Sun on the 17th, moving into the
morning sky. Look for the return of Saturn in October. 1.1 mag (1st) to 1.1 mag
(21st)
- Uranus- At opposition in Pisces on the 17th. 5.7 mag (1st) to 5.7 mag
(21st)
- Neptune- In Capricorn 7.8 mag (1st) to 7.8 mag (21st)
- Ceresand Eta - Finder chart
from the New Zealand RAS (RASNZ) great charts! Northern Hemisphere observers
this time you get to flip the chart or stand on your head!
Vesta chart
temporarily missing...use this
one until site is corrected
Key Dates for September 2009
Days and Times in UT: (help with
time)
Observations are for 10 pm for Northern Hemisphere and 8pm for the
Southern Hemisphere.
Today's sunrise
and sunset times or plan ahead using the US Naval Observatory
Website
Occultation information can be found at the IOTA website!
Astronomical Highlights - September 2009
| 1 |
- Venus 1.2 deg SSW of Beehive cluster (M44) early morning sky |
| 2 |
- Moon near Jupiter in the evening sky |
| 2-3 |
- Jupiter's moons line up in front of and behind Jupiter such that Jupiter
has no moons. See www.spaceweather.com for more details |
| 4 |
- Full Moon 16:03 UT |
|
- Saturn's rings edge on as seen from Earth |
| 6 |
- Mercury stationary beginning retrograde motion |
| 9 |
- September Perseids |
| 10 |
- Moon near Pleiades in the morning sky |
| 9-16 |
- Astronomy A Go Go! at the Afterschool Universe training, the AANC Annual
Meeting, and the ASP conference in San Francisco! |
| 12 |
- Last Quarter Moon |
| 13 |
- Moon very near Mars in the morning sky possible occultation check the IOTA website for
more information |
| 15 |
- Moon near Beehive cluster (m44) in the morning sky |
| 16 |
- Moon at perigee (closest to Earth) 364,053km) |
|
- Zodiacal Lights vis in N latitudes before sunrise in the East next two
weeks (example image, the
reflection of sunlight off interplanetary dust in the plane of the
ecliptic) |
| 17 |
- Moon near Regulus |
|
- Saturn in conjunction with the Sun moving into the morning sky |
|
- Uranus at opposition |
| 18 |
- New Moon at 18:44 UT |
| 20 |
- Mercury at inferior conjunction with the Sun as it moves into the morning
sky |
|
- Venus 1/2 degree NNE from Regulus |
|
- Moon near Spica |
| 22 |
- September equinox 21:22 UT Point in the year where the Sun passes along
the ecliptic into the Southern Hemisphere |
| 24 |
- Moon near Antares in the evening sky possible occultation check the IOTA website for
more information |
| 26 |
- First Quarter Moon |
| 28 |
- Moon at apogee (furtherest from the Earth) 404,432 |
| 29 |
- Moon near Jupiter in the evening sky |
|
October |
| 4 |
- Full Moon |
| 16 |
- In the pre-dawn sky; Arcturus is to the north, the crescent Moon to the
south, and stacked in between, from the horizon, Mercury, Venus, and
Saturn. |
Date information courtesy of: RASC Observer's Handbook, Skymaps.com,
Astronomical Calendar 2009, CalSky, Skymaps.com. sunrise and sunset times
for your home*
Comparative lengths of
day and night
This month our monthly Messier hits some big easy targets, eight more
globular clusters, all are possible in binoculars, and two of these are the
finest globulars which can be seen from northern locations.
Sagittarius is the home of many globular clusters which surround the center
of the Milky Way Galaxy. Seven of the these globulars appear in the Messier
catalog, we will be visiting five of them this month. When you complete the
search for these objects be sure to spend some time scanning this region with
binoculars or a telescope and see what other sights you can discover. I
guarantee you will not be disappointed.
- M13 - The great
globular cluster in Hercules is bright enough to be seen with naked eye and
typically the first GC found by amateur astronomers in the NH. Binoculars easily
show this cluster as a bright fuzzy ball. M13 is partially resolvable in small
aperture telescopes and becomes a fantastic swarm of tightly packed individual
stars through large scopes.
- M92 - Another
globular cluster in Hercules, M92 is easy to find in binoculars appearing
slightly dimmer and smaller than M13. As with M13 it is partially resolvable in
small scopes and is a fine sight in large instruments.
- M14 - A small,
bright globular cluster in Ophiuchus. It is a difficult binocular object, look
for a small fuzzy patch of light. Through a telescope M14 is an even patch of
light, the stars not resolvable except through large scopes.
- M22 - This is
the other great globular in our tour this month. Located just above the teapot
asterism in Sagittarius, M22 can be seen with no optical aid. M22 is easy to
find in binoculars, and easy to resolve in telescopes, with about the same
impressiveness as M13.
- M28 - Located
near M22 in Sagittarius, this is a small bright globular. A tough binocular
object, look for a small fuzzy patch. Easily seen in a telescope, but requires
large aperture to resolve individual stars.
- M69, M70, M54 All of these are small
bright globular clusters laying along the bottom of the teapot in Sagittarius.
Very similar in appearance to M28, these are all tough binocular objects
requiring dark skies and possibly averted vision to see. M54 is slightly
brighter and appears more star like through binoculars than the other globulars.
These are all easily seen in telescopes, though not easily resolvable.
From the Astronomical
Connection and the Moncton Center in Canada
From the Tony
Cecce, Corning, NY - Twelve Month Tour of The Messier Catalog
Comets for September 2009
More comet
information at Seiichi
Yoshida's comet website. Also checkout Gary Kronk's comet and meteor pages Skyhound Comet pages
Historical and Current Events...Did you know?
Mark has developed his own website
so let's all trot on over and see the pages of wonderful history he has for us
this month!
Help us out by leaving a donation in the ol' PayPal hator write us a
favorable review in iTunes of Podcast Pickle or iPodder!
Music Scottish Guitar
Quartet -"Romance Within You"
Black
Lab- "See the Sun"
Anne
Farnsworth- "Saturday Morning"
Earth's major motions for 2009
| Perihelion |
|
Jan 4 15(UT) |
| First Cross Quarter Day |
|
Feb 2-6 |
| Equinox |
|
Mar 20 11:44(UT) |
| Second Cross Quarter Day |
|
May 4-7 |
| Solstice |
|
June 21 05:45(UT) |
| Aphelion |
|
July 4 02h (UT) |
| Third Cross Quarter Day |
|
Aug 5-8 |
| Equinox |
|
Sept 22 21:18(UT) |
| Fourth Cross Quarter Day |
|
Nov 5-8 |
| Solstice |
|
Dec 21 17:47(UT) |
Planet Positions for 2009
| 2009 |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
| Venus |
Sgr |
Cap |
Aqr |
Psc |
Tau |
Gem |
Cnc |
Vir |
Vir |
Sco |
Sgr |
Cap |
| Mars |
Sgr |
Cap |
Aqr |
Psc |
Psc |
Ari |
Tau |
Tau |
Gem |
Cnc |
Cnc |
Leo |
| Jupiter |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
| Saturn |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Vir |
Vir |
Vir |
Vir |
Interesting Planet Pairing for 2009
- December 31, 2008 - Jupiter and Mercury - After sunset a
little more than one degree apart in Sagittarius. Pull out the binos and
telescopes because Mercury will be a mere 15 arcminutes from the globular
cluster M75. All three will be together in one field of view in most home
binoculars.
- January 22nd - Venus and Uranus - After sunset 1.3 degrees
apart a few days later on the 29th they are joined by a waxing crescent moon.
- February 23rd - Jupiter, Mars and Mercury - In the early
morning sky just before sunrise the trio are in a space about 2 degrees wide.
Binoculars will be helpful but beware the quickly rising Sun. The Moon, almost
invisible, will be between Mars and the Sun.
- March 23rd - Mars, Moon, Neptune, and Jupiter - Makes a nice
line-up in the morning sky with Neptune just off the tip of the waning crescent
moon.
- April 21st - Venus, Mars, Uranus, waning crescent Moon, Neptune
and Jupiter - all in the pre-dawn sky together. First the right triangle of
Venus, Mars, and Uranus followed by the waning crescent Moon and then finally by
Neptune and Jupiter. Mars will be a faint 1.41 mag so binoculars will be
helpful. The next day, possible occultation of Venus by the Moon. Check the IOTA
website for occultations in your area.
- May 25th - Jupiter and Neptune - Jupiter is less than 1/2
degree South of Neptune in the morning sky. If you have ever had problems
finding Neptune this would be a good time to try, between now and June.
- June 19th - Venus and Mars - In the pre-dawn sky just south of
a waning crescent Moon. Closer to the Sun is Mercury and the Pleiades.
- August 17th - Saturn and Mercury - Very close to the Sun low
in the evening sky. Much better view for Southern viewers.
- September 3rd UT 4:43 - Jupiter hides its Galilean moons. Not
until 2019 will all of Jupiter's Galilean moons orbit in such a way.
- September 4th - Saturn - Not exactly a pairing but the Earth
will cross the plane of the rings from south to north making the rings invisible
- October 16th - Mercury, Venus, and Saturn - All lined up in
the pre-dawn sky close to the horizon. A faint waning crescent is just south of
the trio.
- December 24th - Jupiter and Neptune - Just after sunset
Jupiter and Neptune sit side-by-side just north of delta Capricornus and east of
the "42,44,45 Cap Wall"
Phases of the Moon 2009
(click to enlarge)
Universal Time
NEW MOON FIRST QUARTER FULL MOON LAST QUARTER
d h m d h m d h m d h m
JAN. 4 11 56 JAN. 11 3 27 JAN. 18 2 46
JAN. 26 7 55 FEB. 2 23 13 FEB. 9 14 49 FEB. 16 21 37
FEB. 25 1 35 MAR. 4 7 46 MAR. 11 2 38 MAR. 18 17 47
MAR. 26 16 06 APR. 2 14 34 APR. 9 14 56 APR. 17 13 36
APR. 25 3 23 MAY 1 20 44 MAY 9 4 01 MAY 17 7 26
MAY 24 12 11 MAY 31 3 22 JUNE 7 18 12 JUNE 15 22 15
JUNE 22 19 35 JUNE 29 11 28 JULY 7 9 21 JULY 15 9 53
JULY 22 2 35 JULY 28 22 00 AUG. 6 0 55 AUG. 13 18 55
AUG. 20 10 02 AUG. 27 11 42 SEPT. 4 16 03 SEPT. 12 2 16
SEPT. 18 18 44 SEPT. 26 4 50 OCT. 4 6 10 OCT. 11 8 56
OCT. 18 5 33 OCT. 26 0 42 NOV. 2 19 14 NOV. 9 15 56
NOV. 16 19 14 NOV. 24 21 39 DEC. 2 7 30 DEC. 9 0 13
DEC. 16 12 02 DEC. 24 17 36 DEC. 31 19 13
Eclipses for 2009
January 26 - Annular Solar Eclipse ( see map,
times, and animation!): The first
solar eclipse of 2009 occurs at the Moon's ascending node in western
Capricornus. An annular eclipse will be visible from a wide track that traverses
the Indian Ocean and western Indonesia. A partial eclipse will be seen within
the much larger path of the Moon's penumbral shadow, which includes the southern
third of Africa, Madagascar, Australia except Tasmania, southeast India,
Southeast Asia and Indonesia.
February 09 - Penumbral Lunar Eclipse ( see map,
times): The first lunar eclipse of 2009 is one of four such events during
the year. The first three eclipses are penumbral while the last (on Dec. 31) is
partial. The Feb 09 event is the deepest penumbral eclipse of the year with a
penumbral magnitude of 0.899. It will be easily visible to the naked eye as a
dusky shading in the northern half of the Moon. The times of the major phases
are listed below.
July 07 - Penumbral Lunar Eclipse ( see map,
times.): July's penumbral eclipse is only of academic interest since the
magnitude is just 0.156. Although the Moon will be above the horizon from most
of Canada, the eclipse is so minor as to be completely invisible to the naked
eye.
July 21-22 - Total Solar Eclipse ( see map,
times, and animation!): To make up
for the anemic lunar eclipse earlier in the month, a major total eclipse of the
Sun occurs two weeks later. The path of the Moon's umbral shadow extends across
India, China, a handful of Japanese islands and the South Pacific Ocean (Espenak
and Anderson, 2008). A partial eclipse is seen within the much broader path of
the Moon's penumbral shadow, which includes most of eastern Asia, Indonesia, and
the Pacific Ocean.
August 05-06 - Penumbral Lunar Eclipse ( see map,
times): A shallow penumbral eclipse occurs 15 days after the total solar
eclipse. Since its magnitude is only 0.402, it will not be visible to the naked
eye.
December 31 - Penumbral Lunar Eclipse ( see map,
times): The last eclipse of 2009 occurs on New Year's Eve. This minor
partial lunar eclipse takes place in Gemini, and is visible primarily from the
Eastern Hemisphere (Figure 8). Greatest eclipse takes place at 19:23 UT when the
eclipse magnitude will reach 0.0763.
Eclipse information from: NASA Eclipse
Homepage, Eclipses
Online (HM Nautical Almanac Office, UK in coordination with the U.S. Naval Observatory)
| Shower |
Activity Period |
Maximum |
Radiant |
Velocity |
r |
ZHR |
Class |
Moon |
| |
|
Date |
S. L. |
R.A. |
Dec. |
km/s |
|
|
|
|
| Antihelion Source (ANT) |
Dec 14-Sep 07 |
- |
- |
- |
- |
30 |
3.0 |
3 |
II |
- |
| Quadrantids (QUA) |
Dec 26-Jan 13 |
Jan 03 |
283°16 |
15:20 |
+49° |
42 |
2.1 |
120 |
I |
6 |
| Alpha Centaurids (ACE) |
Jan 28-Feb 21 |
Feb 07 |
319°2 |
14:00 |
-59° |
56 |
2.0 |
5 |
II |
12 |
| Delta Leonids (DLE) |
Feb 15-Mar 10 |
Feb 25 |
336° |
11:12 |
+16° |
23 |
3.0 |
2 |
II |
0 |
| Gamma Normids (GNO) |
Feb 25-Mar 22 |
Mar 13 |
353° |
16:36 |
-51° |
56 |
2.4 |
4 |
II |
16 |
| Lyrids (LYR) |
Apr 16-Apr 27 |
Apr 23 |
033° |
18:12 |
+33° |
46 |
2.1 |
18 |
I |
27 |
| Pi Puppids (PPU) |
Apr 15-Apr 28 |
Apr 23 |
033°5 |
07:20 |
-45° |
18 |
2.0 |
var |
III |
27 |
| Eta Aquarids (ETA) |
Apr 27-May 23 |
May 07 |
047° |
22:36 |
-01° |
68 |
2.4 |
60 |
I |
12 |
| Eta Lyrids (ELY) |
May 06-May 14 |
May 10 |
050° |
19:22 |
+43° |
43 |
3.0 |
3 |
II |
15 |
| June Bootids (JBO) |
Jun 22-Jul 02 |
Jun 27 |
095°7 |
14:56 |
+48° |
18 |
2.2 |
var |
III |
5 |
| Piscis Austrinids (PAU) |
Jul 15-Aug 10 |
Jul 28 |
125° |
22:44 |
-30° |
35 |
3.2 |
5 |
II |
7 |
| Alpha Capricornids (CAP) |
Jul 12-Aug 08 |
Jul 28 |
125° |
20:20 |
-10° |
24 |
2.5 |
4 |
II |
7 |
| Delta Aquarids (SDA) |
Jul 21-Aug 30 |
Jul 30 |
127° |
22:42 |
-17° |
43 |
3.2 |
20 |
I |
9 |
| Perseids (PER) |
Jul 13-Aug 26 |
Aug 12 |
140° |
03:12 |
+58° |
59 |
2.6 |
100 |
I |
20 |
| Kappa Cygnids (KCG) |
Aug 03-Aug 25 |
Aug 17 |
145° |
19:04 |
+59° |
25 |
3.0 |
3 |
II |
25 |
| Alpha Aurigids (AUR) |
Aug 28-Sep 03 |
Sep 01 |
158°6 |
06:06 |
+39° |
65 |
2.6 |
7 |
II |
11 |
| September Perseids (SPR) |
Sep 06-Sep 13 |
Sep 10 |
168° |
03:12 |
+40° |
65 |
2.9 |
5 |
II |
19 |
| Delta Aurigids (DAU) |
Sep 18-Oct 10 |
Sep 29 |
186° |
05:52 |
+49° |
64 |
2.9 |
2 |
II |
13 |
| Draconids (GIA) |
Oct 06-Oct 10 |
Oct 08 |
195°4 |
17:28 |
+54° |
20 |
2.6 |
var |
III |
18 |
| Southern Taurids (STA) |
Sep 18-Nov 26 |
Oct 11 |
198° |
02:18 |
+09° |
29 |
2.3 |
5 |
II |
21 |
| Epsilon Geminids (EGE) |
Oct 18-Oct 21 |
Oct 20 |
207° |
06:48 |
+28° |
71 |
3.0 |
2 |
II |
2 |
| Orionids (ORI) |
Sep 28-Nov 10 |
Oct 21 |
208° |
06:22 |
+16° |
68 |
2.5 |
23 |
I |
3 |
| Leo Minorids (LMI) |
Oct 17-Oct 27 |
Oct 23 |
209° |
10:40 |
+37° |
61 |
2.7 |
2 |
II |
4 |
| Northern Taurids (NTA) |
Oct 20-Nov 29 |
Nov 13 |
231° |
03:52 |
+22° |
29 |
2.3 |
5 |
II |
25 |
| Leonids (LEO) |
Nov 07-Nov 28 |
Nov 18 |
236° |
10:16 |
+22° |
71 |
2.5 |
var |
III |
1 |
| Alpha Monocerotids (AMO) |
Nov 15-Nov 25 |
Nov 21 |
239°32 |
07:48 |
+01° |
65 |
2.4 |
var |
III |
4 |
| Dec Phoenicids (PHO) |
Nov 28-Dec 09 |
Dec 06 |
254°25 |
01:12 |
-53° |
18 |
2.8 |
var |
III |
18 |
| Puppid/Velids (PUP) |
Dec 01-Dec 15 |
Dec 07 |
255° |
08:12 |
-45° |
40 |
2.9 |
10 |
I |
19 |
| Monocerotids (MON) |
Dec 06-Dec 20 |
Dec 07 |
255° |
06:32 |
+09° |
41 |
3.0 |
2 |
II |
10 |
| Sigma Hydrids (HYD) |
Nov 22-Dec 23 |
Dec 09 |
257° |
08:24 |
+03° |
60 |
3.0 |
3 |
II |
21 |
| Geminids (GEM) |
Dec 05-Dec 19 |
Dec 14 |
262°2 |
07:36 |
+32° |
35 |
2.6 |
120 |
I |
26 |
| Coma Berenicids (COM) |
Dec 10-Jan 25 |
Dec 19 |
268° |
11:40 |
+25° |
64 |
3.0 |
5 |
II |
3 |
| Ursids (URS) |
Dec 16-Dec 25 |
Dec 22 |
270°7 |
14:34 |
+75° |
32 |
3.0 |
10 |
I |
5 |
Information and Table Template Courtesy The American Meteor Society, International Meteor Organization, and Meteors Online.
Shower: named for the constellation or closest star within a
constellation where the radiant is located at maximum activity.
Activity Period: the dates when the ZHR (Zenith Hourly Rates) are
equal to or greater than one.
Maximum: the date on which the maximum activity is expected to occur.
S.L.: the equivalent solar longitude of the date of maximum
activity. Solar longitude is measured in degrees (0-359) with 0 occurring at the
exact moment of the spring equinox, 90 at the summer solstice, 180 at the
autumnal equinox, and 270 at the winter solstice.
Radiant: the area in the sky where shower meteors seem to appear from.
This position is given in right ascension (celestial longitude) and
declination (celestial latitude).
Velocity: the velocity at which shower meteors strike the Earth's
atmosphere. The velocity depends on the angle meteoroids (meteors in space)
intersect the Earth. Meteoroids orbiting in the opposite direction of the Earth
and striking the atmosphere head-on are much faster than those orbiting in the
same direction as the Earth. This velocity is measured in kilometers per second.
r: The Population Index, An estimate of the ratio of the number
of meteors in subsequent magnitude classes. Simply stated: the lower the "r"
value, the resulting overall mean magnitude of each shower will be brighter. "r"
usually ranges from 2.0 (bright) to 3.5 (faint).
ZHR: Zenith Hourly Rate, the average maximum number of shower
meteors visible per hour if the radiant is located exactly overhead and the
limiting magnitude equals +6.5. Actual counts rarely reach this figure as the
zenith angle of the radiant is usually less and the limiting magnitude is
usually lower. ZHR is a useful tool when comparing the actual observed rates
between individual observers as it sets observing conditions for all to the same
standards.
Class: A scale developed by Robert Lunsford to group meteor showers by
their intensity:
Class I: the strongest annual showers with ZHR's normally ten or
better.
Class II: reliable minor showers with ZHR's normally three or better.
Class III: showers with widely variable rates. They may be strong one
year and totally inactive the next.
Class IV: weak minor showers with ZHR's rarely exceeding three. The
study of these showers is best left to experienced observers who use plotting
and angular velocity estimates to determine shower association. Observers with
less experience are urged to limit their shower associations to showers with a
rating of I to III. These showers are also good targets for video and
photographic work.
Moon: the age of the moon in days where 0 is new, 7 is first quarter,
14 is full, and 21 is last quarter. Meteor activity is best seen in the absence
of moonlight so showers reaching maximum activity when the moon is less than 10
days old or more than 25 are much more favorably observed than those situated
closer to the full moon.
Information from the "Observer's Handbook 2009" RASC
Direct download: AAGG_sky_tour_Sept_09.mp3
Category: Sky Tours
-- posted at: 8:46 AM |
|
Thu, 6 August 2009
I am still in Chicago at the Citizen Sky Conference (we introduced Citizen Sky last month) I'm finding that recording in Chicago means you have trains interrupting the podcast about every 4 minutes so I have decided to wait until I get back home to finish the podcast. I appreciate your patience...and as a reward here is a little treat for you! Lite-Bright Episilon AurigaeEnjoy and I will talk to you soon! Category: News Updates
-- posted at: 3:28 PM |
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Wed, 1 July 2009
Astronomy a Go Go! July Sky Tour
This tool displays the approximate Moon phases for a
given month(images are close approximations). For official phase times and dates
for this month and past months are available from the U.S. Naval
Observatory.
Astronomical Online
Glossary
Download this month's sky map!Skymaps.com is our favorite monthly
skymap provider. Download either the Northern hemisphere, Equatorial, or
Southern Hemisphere sky map so you can follow along with our viewing
sessions.
Creator: Kym Thalassoudis
Southern Hemisphere Additional InformationAs Astronomy a Go Go! finds
its home in the higher Northern latitudes those of you who live south of the
equator will benefit from these two Southern Hemisphere sites: Royal
Astronomical Society of New Zealand's Southern Hemisphere Calendar RASNZ site (absolutely
outstanding) and
Southern Sky Watch.
Planets for July 2009
July Morning Planets
(click images to enlarge)
Beginning of the month
Pre-dawn, July 18th
- Mercury-in superior conjunction on the 14th. If you are on the path
of the Total Solar Eclipse then look for Mercury 9 degrees NE of the Sun. At the
end of the month, Southern viewers can catch Mercury in the early evening. -0.9
mag (1st) to -1.3 mag (21st)
- Venus- still fantastic in the morning pre-dawn sky. Since Venus is
moving towards the North, as the Sun heads South, her placement it spectacular
for N. Hemisphere viewers. On the 14th she will be just 3 degrees from Aldebaran
and the Hyades -4.0 mag (1st) to -3.9 mag (21st)
- Mars- moves into Taurus on the 2nd. Mars, Venus, the waning crescent
Moon, and the Hyades make a lovely cluster on the 18th. Compare Mars, and its
color, to that of Aldebaran. 1.1 (1st) to 1.1 mag (21st)
- Jupiter- will be ~ .5 degree from Neptune on the 13th! Jupiter will
be at opposition on August 14th. -2.7 mag (1st) to -2.7 mag (21st)
- Saturn- strangely faint low in the west after sunset! The combination
of the rings near edge on and the receding gas giant decrease the apparent
magnitude. 1.0 mag (1st) to 1.0 mag (21st)
- Uranus- In Aquarius 5.9 mag (1st) to 5.9 mag (21st)
- Neptune- In Capricorn 8.0 mag (1st) to 7.9 mag (21st)
- Ceresand Eta - Finder chart
from the New Zealand RAS (RASNZ) great charts! Northern Hemisphere observers
this time you get to flip the chart or stand on your head!
Vesta chart
temporarily missing...use this
one until site is corrected
Jupiter, Neptune, Uranus Mid-month
Key Dates for July 2009
Days and Times in UT: (help with
time)
Observations are for 10 pm for Northern Hemisphere and 8pm for the
Southern Hemisphere.
Today's sunrise
and sunset times or plan ahead using the US Naval Observatory
Website
Occultation information can be found at the IOTA website!
Astronomical Highlights - July 2009
| 3 |
- Venus 7 deg S of the Pleiades |
| 4 |
- Earth at Aphelion (farthest from the Sun)(2:00 UT) Sun-Earth distance
1.01668 AU or 152.1 million km |
|
- Antares 0.5 deg S of Moon, check the IOTA website for
occultations information for your area. |
|
- Beginning of intense International Space Station fly-by for N.America see
Science@NASA
and Heavens Above for more information
and flyby times in your area. |
| 6 |
- One month away from the beginning of the Epsilon Aurigae eclipse...see
more below |
| 7 |
- Full Moon (smallest in 2009) Penumbral Lunar eclipse (see links, below, in
the annual section) The Moon just kisses the penumbral shadow, not a good naked
eye candidate. |
|
- Moon at apogee (406232) |
| 10 |
- Mars 5 deg S of Pleiades, Jupiter 4 deg S of the Moon |
| 13 |
- Jupiter 0.6 deg S of Neptune |
| 15 |
- Last Quarter Moon |
| 16-19 |
- Astronomy a Go Go! at the TAS Summer Star Party! |
| 21 |
- Moon at perigee (357463 km) Total Solar Eclipse (July 21-22)(see links,
below, in the annual section) Large tides |
| 22 |
- New Moon (2:35 UT) |
| 24 |
- Astronomy A Go Go! and TAS at the Mt. Rainier Star Party! Paradise Visitor
Center (Friday Night Only) |
| 28 |
- First Quarter (22:00 UT) |
| 29 |
- Peak of the S. delta Aquarid meteor shower |
| 31 |
- Antares 0.5 deg S of Moon, check the IOTA website for
occultations information for your area. |
Date information courtesy of: RASC Observer's Handbook, Skymaps.com,
Astronomical Calendar 2009, CalSky, Skymaps.com. sunrise and sunset times
for your home*
Comparative lengths of
day and night
Great Amateur Activity
For those in the high Northern Hemisphere, Capella, the "she goat" in
Aurigae, is circumpolar. At my 47 deg North, Capella disappears behind the
treeline, and into the light polluted horizon, but she pops up in a few hours
and is easy to find. Also easy to find are "The Kids" the small, long, triangle
of stars just to the Southwest of Capella. However, this summer one of those
kids, Epsilon Aurigae, usually the brightest of the trio, will drop in
brightness....for about two years. Epsilon Aurigae, or Almaaz, is an eclipsing
binary and beginning in Aug it will be eclipsed by its invisible companion for
714 days! Brightest of the three "Kids" Epsilon Aurigae will dim from 3.0 mag to
about half of its brightness, a little trick it performs every 27.1 years.
Epsilon Aurigae has some definite quirks and more eyes are needed to help
scientist figure out what Epsilon Aurigae's invisible partner really is! To find
out more visit:
Not as many
objects as wait for the summer Milkyway to rise into better view later this
summer, but much of what there is to see can be accomplished with binoculars.
(This is, in fact, my favorite time of the year for bino viewing.) Our quarry
will consist of six globular clusters and one very bright galaxy. Small scope
and bino heaven.
- M3
- This globular cluster in Canes Venatici is one of the brightest objects in
the sky. In binoculars this object is definitely not star like, but more of a
bright, small snowball easy to see. Small telescopes will begin to resolve M3
into individual stars. The hardest part of this object is locating it in a
portion of sky that contains few bright landmarks.
- M53
- Another globular cluster in Canes Venatici. While not quite as big or bright
as M3 it is still an obvious binocular object. Resolvable in small telescopes,
it as easy object to find sharing the same low power telescope field as fifth
magnitude Alpha Coma Berenices.
- M5
- A big, bright globular cluster located in Serpens Caput. M5 is as nice as M3
but lies near a fifth magnitude naked eye star (5 Serpentis) making it an easy
object to find.
- M68
- An eighth magnitude globular cluster in Hydra, M68 is a difficult binocular
object for Northern observers. It appears as a faint fuzz spot in binoculars,
you may need to use averted vision or large binoculars to find this one.
Appearing as a round fuzzy patch in a 8" telescope, you will need a much larger
aperature to really resolve it.
- M83
- A face on spiral in Hydra. M83 is fairly easy in binoculars as a faint,
fuzzy patch of light. In a telescope look for a large patch of light with a
bright center.
- M4
- A big bright globular in Scorpius, easily located near Antares. This is an
easy binocular object appearing as a round snowball. Partially resolvable in a
telescope, the trade mark of this globular is a line of bright stars crossing
the center.
- M80
- This is the smallest and faintest globular cluster this month. Located in
Scopius, M80 is a very tough binocular object appearing as a faint star with
slight fuzziness around the edges. This is confirmed with a telescope, M80 has a
bright central condensation in the middle of faint fuzz. It is one of the
Messier objects that even through a medium telescope still looks like a comet.
From the Tony
Cecce, Corning, NY - Twelve Month Tour of The Messier Catalog
Comets for July 2009
More comet
information at Seiichi
Yoshida's comet website. Also checkout Gary Kronk's comet and meteor pages Skyhound Comet pages
Historical and Current Events...Did you know?
Mark has developed his own website
so let's all trot on over and see the pages of wonderful history he has for us
this month!
Help us out by leaving a donation in the ol' PayPal hator write us a
favorable review in iTunes of Podcast Pickle or iPodder!
Music Scottish Guitar
Quartet -"Romance Within You"
Black
Lab- "See the Sun"
Anne
Farnsworth- "Saturday Morning"
Earth's major motions for 2009
| Perihelion |
|
Jan 4 15(UT) |
| First Cross Quarter Day |
|
Feb 2-6 |
| Equinox |
|
Mar 20 11:44(UT) |
| Second Cross Quarter Day |
|
May 4-7 |
| Solstice |
|
June 21 05:45(UT) |
| Aphelion |
|
July 4 02h (UT) |
| Third Cross Quarter Day |
|
Aug 5-8 |
| Equinox |
|
Sept 22 21:18(UT) |
| Fourth Cross Quarter Day |
|
Nov 5-8 |
| Solstice |
|
Dec 21 17:47(UT) |
Planet Positions for 2009
| 2009 |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
| Venus |
Sgr |
Cap |
Aqr |
Psc |
Tau |
Gem |
Cnc |
Vir |
Vir |
Sco |
Sgr |
Cap |
| Mars |
Sgr |
Cap |
Aqr |
Psc |
Psc |
Ari |
Tau |
Tau |
Gem |
Cnc |
Cnc |
Leo |
| Jupiter |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
| Saturn |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Vir |
Vir |
Vir |
Vir |
Interesting Planet Pairing for 2009
- December 31, 2008 - Jupiter and Mercury - After sunset a
little more than one degree apart in Sagittarius. Pull out the binos and
telescopes because Mercury will be a mere 15 arcminutes from the globular
cluster M75. All three will be together in one field of view in most home
binoculars.
- January 22nd - Venus and Uranus - After sunset 1.3 degrees
apart a few days later on the 29th they are joined by a waxing crescent moon.
- February 23rd - Jupiter, Mars and Mercury - In the early
morning sky just before sunrise the trio are in a space about 2 degrees wide.
Binoculars will be helpful but beware the quickly rising Sun. The Moon, almost
invisible, will be between Mars and the Sun.
- March 23rd - Mars, Moon, Neptune, and Jupiter - Makes a nice
line-up in the morning sky with Neptune just off the tip of the waning crescent
moon.
- April 21st - Venus, Mars, Uranus, waning crescent Moon, Neptune
and Jupiter - all in the pre-dawn sky together. First the right triangle of
Venus, Mars, and Uranus followed by the waning crescent Moon and then finally by
Neptune and Jupiter. Mars will be a faint 1.41 mag so binoculars will be
helpful. The next day, possible occultation of Venus by the Moon. Check the IOTA
website for occultations in your area.
- May 25th - Jupiter and Neptune - Jupiter is less than 1/2
degree South of Neptune in the morning sky. If you have ever had problems
finding Neptune this would be a good time to try, between now and June.
- June 19th - Venus and Mars - In the pre-dawn sky just south of
a waning crescent Moon. Closer to the Sun is Mercury and the Pleiades.
- August 17th - Saturn and Mercury - Very close to the Sun low
in the evening sky. Much better view for Southern viewers.
- September 3rd UT 4:43 - Jupiter hides its Galilean moons. Not
until 2019 will all of Jupiter's Galilean moons orbit in such a way.
- September 4th - Saturn - Not exactly a pairing but the Earth
will cross the plane of the rings from south to north making the rings invisible
- October 16th - Mercury, Venus, and Saturn - All lined up in
the pre-dawn sky close to the horizon. A faint waning crescent is just south of
the trio.
- December 24th - Jupiter and Neptune - Just after sunset
Jupiter and Neptune sit side-by-side just north of delta Capricornus and east of
the "42,44,45 Cap Wall"
Phases of the Moon 2009
(click to enlarge)
Universal Time
NEW MOON FIRST QUARTER FULL MOON LAST QUARTER
d h m d h m d h m d h m
JAN. 4 11 56 JAN. 11 3 27 JAN. 18 2 46
JAN. 26 7 55 FEB. 2 23 13 FEB. 9 14 49 FEB. 16 21 37
FEB. 25 1 35 MAR. 4 7 46 MAR. 11 2 38 MAR. 18 17 47
MAR. 26 16 06 APR. 2 14 34 APR. 9 14 56 APR. 17 13 36
APR. 25 3 23 MAY 1 20 44 MAY 9 4 01 MAY 17 7 26
MAY 24 12 11 MAY 31 3 22 JUNE 7 18 12 JUNE 15 22 15
JUNE 22 19 35 JUNE 29 11 28 JULY 7 9 21 JULY 15 9 53
JULY 22 2 35 JULY 28 22 00 AUG. 6 0 55 AUG. 13 18 55
AUG. 20 10 02 AUG. 27 11 42 SEPT. 4 16 03 SEPT. 12 2 16
SEPT. 18 18 44 SEPT. 26 4 50 OCT. 4 6 10 OCT. 11 8 56
OCT. 18 5 33 OCT. 26 0 42 NOV. 2 19 14 NOV. 9 15 56
NOV. 16 19 14 NOV. 24 21 39 DEC. 2 7 30 DEC. 9 0 13
DEC. 16 12 02 DEC. 24 17 36 DEC. 31 19 13
Eclipses for 2009
January 26 - Annular Solar Eclipse ( see map,
times, and animation!): The first
solar eclipse of 2009 occurs at the Moon's ascending node in western
Capricornus. An annular eclipse will be visible from a wide track that traverses
the Indian Ocean and western Indonesia. A partial eclipse will be seen within
the much larger path of the Moon's penumbral shadow, which includes the southern
third of Africa, Madagascar, Australia except Tasmania, southeast India,
Southeast Asia and Indonesia.
February 09 - Penumbral Lunar Eclipse ( see map,
times): The first lunar eclipse of 2009 is one of four such events during
the year. The first three eclipses are penumbral while the last (on Dec. 31) is
partial. The Feb 09 event is the deepest penumbral eclipse of the year with a
penumbral magnitude of 0.899. It will be easily visible to the naked eye as a
dusky shading in the northern half of the Moon. The times of the major phases
are listed below.
July 07 - Penumbral Lunar Eclipse ( see map,
times.): July's penumbral eclipse is only of academic interest since the
magnitude is just 0.156. Although the Moon will be above the horizon from most
of Canada, the eclipse is so minor as to be completely invisible to the naked
eye.
July 21-22 - Total Solar Eclipse ( see map,
times, and animation!): To make up
for the anemic lunar eclipse earlier in the month, a major total eclipse of the
Sun occurs two weeks later. The path of the Moon's umbral shadow extends across
India, China, a handful of Japanese islands and the South Pacific Ocean (Espenak
and Anderson, 2008). A partial eclipse is seen within the much broader path of
the Moon's penumbral shadow, which includes most of eastern Asia, Indonesia, and
the Pacific Ocean.
August 05-06 - Penumbral Lunar Eclipse ( see map,
times): A shallow penumbral eclipse occurs 15 days after the total solar
eclipse. Since its magnitude is only 0.402, it will not be visible to the naked
eye.
December 31 - Penumbral Lunar Eclipse ( see map,
times): The last eclipse of 2009 occurs on New Year's Eve. This minor
partial lunar eclipse takes place in Gemini, and is visible primarily from the
Eastern Hemisphere (Figure 8). Greatest eclipse takes place at 19:23 UT when the
eclipse magnitude will reach 0.0763.
Eclipse information from: NASA Eclipse
Homepage, Eclipses
Online (HM Nautical Almanac Office, UK in coordination with the U.S. Naval Observatory)
| Shower |
Activity Period |
Maximum |
Radiant |
Velocity |
r |
ZHR |
Class |
Moon |
| |
|
Date |
S. L. |
R.A. |
Dec. |
km/s |
|
|
|
|
| Antihelion Source (ANT) |
Dec 14-Sep 07 |
- |
- |
- |
- |
30 |
3.0 |
3 |
II |
- |
| Quadrantids (QUA) |
Dec 26-Jan 13 |
Jan 03 |
283°16 |
15:20 |
+49° |
42 |
2.1 |
120 |
I |
6 |
| Alpha Centaurids (ACE) |
Jan 28-Feb 21 |
Feb 07 |
319°2 |
14:00 |
-59° |
56 |
2.0 |
5 |
II |
12 |
| Delta Leonids (DLE) |
Feb 15-Mar 10 |
Feb 25 |
336° |
11:12 |
+16° |
23 |
3.0 |
2 |
II |
0 |
| Gamma Normids (GNO) |
Feb 25-Mar 22 |
Mar 13 |
353° |
16:36 |
-51° |
56 |
2.4 |
4 |
II |
16 |
| Lyrids (LYR) |
Apr 16-Apr 27 |
Apr 23 |
033° |
18:12 |
+33° |
46 |
2.1 |
18 |
I |
27 |
| Pi Puppids (PPU) |
Apr 15-Apr 28 |
Apr 23 |
033°5 |
07:20 |
-45° |
18 |
2.0 |
var |
III |
27 |
| Eta Aquarids (ETA) |
Apr 27-May 23 |
May 07 |
047° |
22:36 |
-01° |
68 |
2.4 |
60 |
I |
12 |
| Eta Lyrids (ELY) |
May 06-May 14 |
May 10 |
050° |
19:22 |
+43° |
43 |
3.0 |
3 |
II |
15 |
| June Bootids (JBO) |
Jun 22-Jul 02 |
Jun 27 |
095°7 |
14:56 |
+48° |
18 |
2.2 |
var |
III |
5 |
| Piscis Austrinids (PAU) |
Jul 15-Aug 10 |
Jul 28 |
125° |
22:44 |
-30° |
35 |
3.2 |
5 |
II |
7 |
| Alpha Capricornids (CAP) |
Jul 12-Aug 08 |
Jul 28 |
125° |
20:20 |
-10° |
24 |
2.5 |
4 |
II |
7 |
| Delta Aquarids (SDA) |
Jul 21-Aug 30 |
Jul 30 |
127° |
22:42 |
-17° |
43 |
3.2 |
20 |
I |
9 |
| Perseids (PER) |
Jul 13-Aug 26 |
Aug 12 |
140° |
03:12 |
+58° |
59 |
2.6 |
100 |
I |
20 |
| Kappa Cygnids (KCG) |
Aug 03-Aug 25 |
Aug 17 |
145° |
19:04 |
+59° |
25 |
3.0 |
3 |
II |
25 |
| Alpha Aurigids (AUR) |
Aug 28-Sep 03 |
Sep 01 |
158°6 |
06:06 |
+39° |
65 |
2.6 |
7 |
II |
11 |
| September Perseids (SPR) |
Sep 06-Sep 13 |
Sep 10 |
168° |
03:12 |
+40° |
65 |
2.9 |
5 |
II |
19 |
| Delta Aurigids (DAU) |
Sep 18-Oct 10 |
Sep 29 |
186° |
05:52 |
+49° |
64 |
2.9 |
2 |
II |
13 |
| Draconids (GIA) |
Oct 06-Oct 10 |
Oct 08 |
195°4 |
17:28 |
+54° |
20 |
2.6 |
var |
III |
18 |
| Southern Taurids (STA) |
Sep 18-Nov 26 |
Oct 11 |
198° |
02:18 |
+09° |
29 |
2.3 |
5 |
II |
21 |
| Epsilon Geminids (EGE) |
Oct 18-Oct 21 |
Oct 20 |
207° |
06:48 |
+28° |
71 |
3.0 |
2 |
II |
2 |
| Orionids (ORI) |
Sep 28-Nov 10 |
Oct 21 |
208° |
06:22 |
+16° |
68 |
2.5 |
23 |
I |
3 |
| Leo Minorids (LMI) |
Oct 17-Oct 27 |
Oct 23 |
209° |
10:40 |
+37° |
61 |
2.7 |
2 |
II |
4 |
| Northern Taurids (NTA) |
Oct 20-Nov 29 |
Nov 13 |
231° |
03:52 |
+22° |
29 |
2.3 |
5 |
II |
25 |
| Leonids (LEO) |
Nov 07-Nov 28 |
Nov 18 |
236° |
10:16 |
+22° |
71 |
2.5 |
var |
III |
1 |
| Alpha Monocerotids (AMO) |
Nov 15-Nov 25 |
Nov 21 |
239°32 |
07:48 |
+01° |
65 |
2.4 |
var |
III |
4 |
| Dec Phoenicids (PHO) |
Nov 28-Dec 09 |
Dec 06 |
254°25 |
01:12 |
-53° |
18 |
2.8 |
var |
III |
18 |
| Puppid/Velids (PUP) |
Dec 01-Dec 15 |
Dec 07 |
255° |
08:12 |
-45° |
40 |
2.9 |
10 |
I |
19 |
| Monocerotids (MON) |
Dec 06-Dec 20 |
Dec 07 |
255° |
06:32 |
+09° |
41 |
3.0 |
2 |
II |
10 |
| Sigma Hydrids (HYD) |
Nov 22-Dec 23 |
Dec 09 |
257° |
08:24 |
+03° |
60 |
3.0 |
3 |
II |
21 |
| Geminids (GEM) |
Dec 05-Dec 19 |
Dec 14 |
262°2 |
07:36 |
+32° |
35 |
2.6 |
120 |
I |
26 |
| Coma Berenicids (COM) |
Dec 10-Jan 25 |
Dec 19 |
268° |
11:40 |
+25° |
64 |
3.0 |
5 |
II |
3 |
| Ursids (URS) |
Dec 16-Dec 25 |
Dec 22 |
270°7 |
14:34 |
+75° |
32 |
3.0 |
10 |
I |
5 |
Information and Table Template Courtesy The American Meteor Society, International Meteor Organization, and Meteors Online.
Shower: named for the constellation or closest star within a
constellation where the radiant is located at maximum activity.
Activity Period: the dates when the ZHR (Zenith Hourly Rates) are
equal to or greater than one.
Maximum: the date on which the maximum activity is expected to occur.
S.L.: the equivalent solar longitude of the date of maximum
activity. Solar longitude is measured in degrees (0-359) with 0 occurring at the
exact moment of the spring equinox, 90 at the summer solstice, 180 at the
autumnal equinox, and 270 at the winter solstice.
Radiant: the area in the sky where shower meteors seem to appear from.
This position is given in right ascension (celestial longitude) and
declination (celestial latitude).
Velocity: the velocity at which shower meteors strike the Earth's
atmosphere. The velocity depends on the angle meteoroids (meteors in space)
intersect the Earth. Meteoroids orbiting in the opposite direction of the Earth
and striking the atmosphere head-on are much faster than those orbiting in the
same direction as the Earth. This velocity is measured in kilometers per second.
r: The Population Index, An estimate of the ratio of the number
of meteors in subsequent magnitude classes. Simply stated: the lower the "r"
value, the resulting overall mean magnitude of each shower will be brighter. "r"
usually ranges from 2.0 (bright) to 3.5 (faint).
ZHR: Zenith Hourly Rate, the average maximum number of shower
meteors visible per hour if the radiant is located exactly overhead and the
limiting magnitude equals +6.5. Actual counts rarely reach this figure as the
zenith angle of the radiant is usually less and the limiting magnitude is
usually lower. ZHR is a useful tool when comparing the actual observed rates
between individual observers as it sets observing conditions for all to the same
standards.
Class: A scale developed by Robert Lunsford to group meteor showers by
their intensity:
Class I: the strongest annual showers with ZHR's normally ten or
better.
Class II: reliable minor showers with ZHR's normally three or better.
Class III: showers with widely variable rates. They may be strong one
year and totally inactive the next.
Class IV: weak minor showers with ZHR's rarely exceeding three. The
study of these showers is best left to experienced observers who use plotting
and angular velocity estimates to determine shower association. Observers with
less experience are urged to limit their shower associations to showers with a
rating of I to III. These showers are also good targets for video and
photographic work.
Moon: the age of the moon in days where 0 is new, 7 is first quarter,
14 is full, and 21 is last quarter. Meteor activity is best seen in the absence
of moonlight so showers reaching maximum activity when the moon is less than 10
days old or more than 25 are much more favorably observed than those situated
closer to the full moon.
Information from the "Observer's Handbook 2009" RASC
Direct download: AAGG_sky_tour_July_2009.mp3
Category: Sky Tours
-- posted at: 4:57 AM |
|
Wed, 3 June 2009
I had forgotten just how much time finals, graduations, weddings, and final paper consume! The podcast is running behind all of these...expect it around the 9th.
Sorry everyone...life does get complicated.
Alice
Category: Problems
-- posted at: 8:32 PM |
|
Mon, 4 May 2009
Astronomy a Go Go! May Sky Tour
This tool displays the approximate Moon phases for a
given month(images are close approximations). For official phase times and dates
for this month and past months are available from the U.S. Naval
Observatory.
Astronomical Online
Glossary
Download this month's sky map!Skymaps.com is our favorite monthly
skymap provider. Download either the
Northern hemisphere sky map
or theSouthern hemisphere sky
map so you can follow along with our viewing sessions.
Creator: Kym
Thalassoudis
Southern Hemisphere Additional InformationAs Astronomy a Go Go! finds
its home in the higher Northern latitudes those of you who live south of the
equator will benefit from these two Southern Hemisphere sites: Royal
Astronomical Society of New Zealand's Southern Hemisphere Calendar RASNZ site (absolutely
outstanding) and
Southern Sky Watch.
Planets for May 2009
April will be a morning viewing month for planets with a lovely lunar meet
and greet with Jupiter and Mars and an occultation of Venus. Saturn is available
for evening viewers!
May Morning Planets
(click images to
enlarge)
Beginning of the month
End of the month
- Mercury- Quickly receding back towards the Sun and will be in
inferior conjunction on May 18th moving into the early morning sky along with
Venus, Mars and Jupiter 1.0 mag (1st) to 5.6 mag (21st)
- Venus- The brightest object low in the morning sky as she moves
towards greatest western elongation in June -4.7 mag (1st) to -4.4 mag (21st)
- Mars- Plays little game of tag with Venus within Pisces this month,
Venus trail about 6 degrees behind Mars. 1.2 (1st) to 1.2 mag (21st)
- Jupiter- Beautiful close to the meridian in the morning sky, rising
at midnight for southern observers this month, in June for northern observers.
(unless you are in Seattle and we have our perpetual planet zapping cloud banks)
-2.2 mag (1st) to -2.2 mag (21st)
- Saturn- In eastern Leo Saturn's were rings were seemingly flat at the
end of April and beginning of May. The rings will open to 4.2 degrees by the
15th, the widest they will be until late November. Saturn begins the month in
retrograde motion, becoming stationary on the 17th before resuming eastward
motion 0.7 mag (1st) to 0.8 mag (21st)
- Uranus- In Aquarius 5.9 mag (1st) to 5.9 mag (21st)
- Neptune- In Capricorn 8.0 mag (1st) to 7.9 mag (21st)
- Ceresand Eta - Finder chart
from the New Zealand RAS (RASNZ) great charts! Northern Hemisphere observers
this time you get to flip the chart or stand on your head!
Vesta chart
temporarily missing...use this
one until site is corrected
Key Dates for May 2009
Days and Times in UT: (help with
time)
Observations are for 10 pm for Northern Hemisphere and 8pm for the
Southern Hemisphere.
Today's sunrise
and sunset times or plan ahead using the US Naval Observatory
Website
Occultation information can be found at the IOTA website!
Astronomical Highlights - May 2009
| 1-3 |
- AAGG will be judging the Astronomy section of the Cascade Challenge!! Go
Girl Scouts! |
| 1 |
- First Quarter Moon (4 UT) |
| 6 |
- Peak of the Eta Aquarid Meteor shower, debris left behind from Halley's
Comet |
| 9 |
- Full Moon (4:01 UT) |
| 10 |
- Moon near Antares (21h UT) Occultation visible from SE Europe, NE Africa
and S.Asia, check the IOTA
website for occultation information for your area. |
| 14 |
- Moon at apogee (404,915 km) |
| 15 |
- Shadow transit of Titan on Saturn 5:30-10:35 UT You will need a 8" or
better aperture |
| 17 |
- Last Quarter Moon (7:26 UT) |
| 18 |
- Mercury at inferior conjunction with the Sun passing into the morning sky
to join Venus, Mars and Jupiter |
| 21 |
- Venus 7 deg S of Moon |
| 21 |
- Mars 7 deg S of Moon |
| 24 |
- New Moon (12:11 UT) |
| 25 |
- Jupiter 0.4 deg S of Neptune |
| 26 |
- Moon at perigee (361,153 km) |
| 27 |
- Jupiter 0.39 deg SSE of Neptune at 10 UT mag -2.4 and +7.19 |
| 31 |
- First Quarter Moon 3:22 UT |
Date information courtesy of: RASC Observer's Handbook, Skymaps.com,
Astronomical Calendar 2009, CalSky, Skymaps.com. sunrise and sunset times
for your home*
Comparative lengths of
day and night
More sites to help with Virgo huntingStart by listening to show 39 from
2007, I take you through one path of 49 galaxies step by step...with pictures
too!
Helpful free maps 7 and 7a
Alan M.
MacRobert's "Mastering
the Virgo Cluster" Sky and Telescope, May 1994 pg 42
-This is the one I
carry in my notebook because I love the route and the map.
Tom Trusock's Cloudy
Nights Article
Steve Gottlieb's Virgo
Mainline Article
A great set of hopping lists from
SEDS
Galaxy hopping in LeoAlan MacRobert's Leo
hopping article in Sky and Telescope
This month we
continue our tour of our nearby neighbors outside the Milky May galaxy. Our
observing will take in 10 more galaxies. Be ready to look for very faint and
small objects. Most are possible to see in binoculars, but you will need a
telescope and dark skies to really enjoy the sights. This is the final warm up
to prepare us for next month's challenge, navigating the Virgo Cluster of
galaxies. When you are done with these objects and give yourself a treat, skip
ahead to the summer globular clusters of M3 or M13. While they are not an
official part of this month's tour they should never be missed whenever they are
available. Besides these bright and spectacular objects are a treat to tired
eyes after a night of galaxy hunting. Be careful, these are so bright after the
other objects that you might want to wear shades.
 M51
- The famous Whirlpool galaxy in Canes Venatici is a bright face on spiral
with a smaller elliptical companion, NGC 5195. Look for a pair of fuzzy patches
of light. The slightly larger and brighter one is M51. Make sure to spend some
time here as there is almost always some spiral structure to be seen, on good
nights the detail possible is unbelievable. This is a difficult but very
possible object in binoculars appearing as a hazy patch of light.
 M63
- Another spiral galaxy in Canes Venatici smaller and fainter than M51, but
seen more edge on so the galaxy appears as an elongated patch of light with a
bright star at one end. Further inspection will show a faint halo around this
patch. A difficult object in binoculars.
 M94
- Just past M63 is another galaxy in Canes Vanitici. Look for a bright fuzzy
star to find the core of M94, surrounded by a faint haze. A tough binocular
object.
 M101
- I consider this face on spiral galaxy in Ursa Major one of the most
difficult Messier objects to find in a telescope. This is a large faint patch of
light almost as big as the full moon. There are no real condensations so use low
power and look for a brighter part of the sky, more of a change in contrast than
an object at first glance, which is the galaxy. Dark skies really help in the
search of this one and are a to find M101 in binoculars.
 M102
- Not an official Messier object in most references, we will look for the
galaxy NGC 5866
which is a somewhat standard insertion. Look for a small, faint patch light that
looks like a short fuzzy line.
 M64
- In a telescope this galaxy in Coma Berenices is a fairly bright, slightly
oval shaped patch of light. Look for the dark lane which gives this galaxy the
common name Black Eye. The galaxy appears as a faint fuzzy patch in binoculars.
 M85
- This elliptical galaxy lies in Coma Berenices just north of the Virgo
Cluster of galaxies. This appears as a bright, but small, patch of light with a
bright stellar core.
 M49
- This is an elliptical galaxy in Virgo just south of the main cluster of
galaxies. M49 is round patch of light with bright center gradually fading to a
round halo. M49 looks like a faint fuzzy star in binoculars.
 M61
- This is a face on spiral galaxy just south of M49 in Virgo, but much
fainter. Look for a faint, round fuzzy patch of light.
 M104
- This is the well known Sombrero galaxy in Virgo. It is bright edge on spiral
galaxy which looks like a bright, elongated streak. It is very possible to see
in binoculars.
From the Tony
Cecce, Corning, NY - Twelve Month Tour of The Messier Catalog
Comets for May 2009
More comet
information at Seiichi
Yoshida's comet website. Also checkout Gary Kronk's comet and meteor pages Skyhound Comet pages
Historical and Current Events...Did you know?
Mark has developed his own website
so let's all trot on over and see the pages of wonderful history he has for us
this month!
Help us out by leaving a donation in the ol' PayPal hator write us a
favorable review in iTunes of Podcast Pickle or iPodder!
Music Scottish Guitar
Quartet -"Romance Within You"
Angelique Kidjo- "Salala"
Antonin Bastian- "Tu Cha Cha Cha"
Earth's major motions for 2009
| Perihelion |
|
Jan 4 15(UT) |
| First Cross Quarter Day |
|
Feb 2-6 |
| Equinox |
|
Mar 20 11:44(UT) |
| Second Cross Quarter Day |
|
May 4-7 |
| Solstice |
|
June 21 05:45(UT) |
| Aphelion |
|
July 4 02h (UT) |
| Third Cross Quarter Day |
|
Aug 5-8 |
| Equinox |
|
Sept 22 21:18(UT) |
| Fourth Cross Quarter Day |
|
Nov 5-8 |
| Solstice |
|
Dec 21 17:47(UT) |
Planet Positions for 2009
| 2009 |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
| Venus |
Sgr |
Cap |
Aqr |
Psc |
Tau |
Gem |
Cnc |
Vir |
Vir |
Sco |
Sgr |
Cap |
| Mars |
Sgr |
Cap |
Aqr |
Psc |
Psc |
Ari |
Tau |
Tau |
Gem |
Cnc |
Cnc |
Leo |
| Jupiter |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
Cap |
| Saturn |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Leo |
Vir |
Vir |
Vir |
Vir |
Interesting Planet Pairing for 2009
- December 31, 2008 - Jupiter and Mercury - After sunset a
little more than one degree apart in Sagittarius. Pull out the binos and
telescopes because Mercury will be a mere 15 arcminutes from the globular
cluster M75. All three will be together in one field of view in most home
binoculars.
- January 22nd - Venus and Uranus - After sunset 1.3 degrees
apart a few days later on the 29th they are joined by a waxing crescent moon.
- February 23rd - Jupiter, Mars and Mercury - In the early
morning sky just before sunrise the trio are in a space about 2 degrees wide.
Binoculars will be helpful but beware the quickly rising Sun. The Moon, almost
invisible, will be between Mars and the Sun.
- March 23rd - Mars, Moon, Neptune, and Jupiter - Makes a nice
line-up in the morning sky with Neptune just off the tip of the waning crescent
moon.
- April 21st - Venus, Mars, Uranus, waning crescent Moon, Neptune
and Jupiter - all in the pre-dawn sky together. First the right triangle of
Venus, Mars, and Uranus followed by the waning crescent Moon and then finally by
Neptune and Jupiter. Mars will be a faint 1.41 mag so binoculars will be
helpful. The next day, possible occultation of Venus by the Moon. Check the IOTA
website for occultations in your area.
- May 25th - Jupiter and Neptune - Jupiter is less than 1/2
degree South of Neptune in the morning sky. If you have ever had problems
finding Neptune this would be a good time to try, between now and June.
- June 19th - Venus and Mars - In the pre-dawn sky just south of
a waning crescent Moon. Closer to the Sun is Mercury and the Pleiades.
- August 17th - Saturn and Mercury - Very close to the Sun low
in the evening sky. Much better view for Southern viewers.
- September 3rd UT 4:43 - Jupiter hides its Galilean moons. Not
until 2019 will all of Jupiter's Galilean moons orbit in such a way.
- September 4th - Saturn - Not exactly a pairing but the Earth
will cross the plane of the rings from south to north making the rings invisible
- October 16th - Mercury, Venus, and Saturn - All lined up in
the pre-dawn sky close to the horizon. A faint waning crescent is just south of
the trio.
- December 24th - Jupiter and Neptune - Just after sunset
Jupiter and Neptune sit side-by-side just north of delta Capricornus and east of
the "42,44,45 Cap Wall"
Phases of the Moon 2009
(click to enlarge)
Universal Time
NEW MOON FIRST QUARTER FULL MOON LAST QUARTER
d h m d h m d h m d h m
JAN. 4 11 56 JAN. 11 3 27 JAN. 18 2 46
JAN. 26 7 55 FEB. 2 23 13 FEB. 9 14 49 FEB. 16 21 37
FEB. 25 1 35 MAR. 4 7 46 MAR. 11 2 38 MAR. 18 17 47
MAR. 26 16 06 APR. 2 14 34 APR. 9 14 56 APR. 17 13 36
APR. 25 3 23 MAY 1 20 44 MAY 9 4 01 MAY 17 7 26
MAY 24 12 11 MAY 31 3 22 JUNE 7 18 12 JUNE 15 22 15
JUNE 22 19 35 JUNE 29 11 28 JULY 7 9 21 JULY 15 9 53
JULY 22 2 35 JULY 28 22 00 AUG. 6 0 55 AUG. 13 18 55
AUG. 20 10 02 AUG. 27 11 42 SEPT. 4 16 03 SEPT. 12 2 16
SEPT. 18 18 44 SEPT. 26 4 50 OCT. 4 6 10 OCT. 11 8 56
OCT. 18 5 33 OCT. 26 0 42 NOV. 2 19 14 NOV. 9 15 56
NOV. 16 19 14 NOV. 24 21 39 DEC. 2 7 30 DEC. 9 0 13
DEC. 16 12 02 DEC. 24 17 36 DEC. 31 19 13
Eclipses for 2009
January 26 - Annular Solar Eclipse ( see map,
times, and animation!): The first
solar eclipse of 2009 occurs at the Moon's ascending node in western
Capricornus. An annular eclipse will be visible from a wide track that traverses
the Indian Ocean and western Indonesia. A partial eclipse will be seen within
the much larger path of the Moon's penumbral shadow, which includes the southern
third of Africa, Madagascar, Australia except Tasmania, southeast India,
Southeast Asia and Indonesia.
February 09 - Penumbral Lunar Eclipse ( see map,
times): The first lunar eclipse of 2009 is one of four such events during
the year. The first three eclipses are penumbral while the last (on Dec. 31) is
partial. The Feb 09 event is the deepest penumbral eclipse of the year with a
penumbral magnitude of 0.899. It will be easily visible to the naked eye as a
dusky shading in the northern half of the Moon. The times of the major phases
are listed below.
July 07 - Penumbral Lunar Eclipse ( see map,
times.): July's penumbral eclipse is only of academic interest since the
magnitude is just 0.156. Although the Moon will be above the horizon from most
of Canada, the eclipse is so minor as to be completely invisible to the naked
eye.
July 21-22 - Total Solar Eclipse ( see map,
times, and animation!): To make up
for the anemic lunar eclipse earlier in the month, a major total eclipse of the
Sun occurs two weeks later. The path of the Moon's umbral shadow extends across
India, China, a handful of Japanese islands and the South Pacific Ocean (Espenak
and Anderson, 2008). A partial eclipse is seen within the much broader path of
the Moon's penumbral shadow, which includes most of eastern Asia, Indonesia, and
the Pacific Ocean.
August 05-06 - Penumbral Lunar Eclipse ( see map,
times): A shallow penumbral eclipse occurs 15 days after the total solar
eclipse. Since its magnitude is only 0.402, it will not be visible to the naked
eye.
December 31 - Penumbral Lunar Eclipse ( see map,
times): The last eclipse of 2009 occurs on New Year's Eve. This minor
partial lunar eclipse takes place in Gemini, and is visible primarily from the
Eastern Hemisphere (Figure 8). Greatest eclipse takes place at 19:23 UT when the
eclipse magnitude will reach 0.0763.
Eclipse information from: NASA Eclipse
Homepage, Eclipses
Online (HM Nautical Almanac Office, UK in coordination with the U.S. Naval Observatory)
| Shower |
Activity Period |
Maximum |
Radiant |
Velocity |
r |
ZHR |
Class |
Moon |
| |
|
Date |
S. L. |
R.A. |
Dec. |
km/s |
|
|
|
|
| Antihelion Source (ANT) |
Dec 14-Sep 07 |
- |
- |
- |
- |
30 |
3.0 |
3 |
II |
- |
| Quadrantids (QUA) |
Dec 26-Jan 13 |
Jan 03 |
283°16 |
15:20 |
+49° |
42 |
2.1 |
120 |
I |
6 |
| Alpha Centaurids (ACE) |
Jan 28-Feb 21 |
Feb 07 |
319°2 |
14:00 |
-59° |
56 |
2.0 |
5 |
II |
12 |
| Delta Leonids (DLE) |
Feb 15-Mar 10 |
Feb 25 |
336° |
11:12 |
+16° |
23 |
3.0 |
2 |
II |
0 |
| Gamma Normids (GNO) |
Feb 25-Mar 22 |
Mar 13 |
353° |
16:36 |
-51° |
56 |
2.4 |
4 |
II |
16 |
| Lyrids (LYR) |
Apr 16-Apr 27 |
Apr 23 |
033° |
18:12 |
+33° |
46 |
2.1 |
18 |
I |
27 |
| Pi Puppids (PPU) |
Apr 15-Apr 28 |
Apr 23 |
033°5 |
07:20 |
-45° |
18 |
2.0 |
var |
III |
27 |
| Eta Aquarids (ETA) |
Apr 27-May 23 |
May 07 |
047° |
22:36 |
-01° |
68 |
2.4 |
60 |
I |
12 |
| Eta Lyrids (ELY) |
May 06-May 14 |
May 10 |
050° |
19:22 |
+43° |
43 |
3.0 |
3 |
II |
15 |
| June Bootids (JBO) |
Jun 22-Jul 02 |
Jun 27 |
095°7 |
14:56 |
+48° |
18 |
2.2 |
var |
III |
5 |
| Piscis Austrinids (PAU) |
Jul 15-Aug 10 |
Jul 28 |
125° |
22:44 |
-30° |
35 |
3.2 |
5 |
II |
7 |
| Alpha Capricornids (CAP) |
Jul 12-Aug 08 |
Jul 28 |
125° |
20:20 |
-10° |
24 |
2.5 |
4 |
II |
7 |
| Delta Aquarids (SDA) |
Jul 21-Aug 30 |
Jul 30 |
127° |
22:42 |
-17° |
43 |
3.2 |
20 |
I |
9 |
| Perseids (PER) |
Jul 13-Aug 26 |
Aug 12 |
140° |
03:12 |
+58° |
59 |
2.6 |
100 |
I |
20 |
| Kappa Cygnids (KCG) |
Aug 03-Aug 25 |
Aug 17 |
145° |
19:04 |
+59° |
25 |
3.0 |
3 |
II |
25 |
| Alpha Aurigids (AUR) |
Aug 28-Sep 03 |
Sep 01 |
158°6 |
06:06 |
+39° |
65 |
2.6 |
7 |
II |
11 |
| September Perseids (SPR) |
Sep 06-Sep 13 |
Sep 10 |
168° |
03:12 |
+40° |
65 |
2.9 |
5 |
II |
19 |
| Delta Aurigids (DAU) |
Sep 18-Oct 10 |
Sep 29 |
186° |
05:52 |
+49° |
64 |
2.9 |
2 |
II |
13 |
| Draconids (GIA) |
Oct 06-Oct 10 |
Oct 08 |
195°4 |
17:28 |
+54° |
20 |
2.6 |
var |
III |
18 |
| Southern Taurids (STA) |
Sep 18-Nov 26 |
Oct 11 |
198° |
02:18 |
+09° |
29 |
2.3 |
5 |
II |
21 |
| Epsilon Geminids (EGE) |
Oct 18-Oct 21 |
Oct 20 |
207° |
06:48 |
+28° |
71 |
3.0 |
2 |
II |
2 |
| Orionids (ORI) |
Sep 28-Nov 10 |
Oct 21 |
208° |
06:22 |
+16° |
68 |
2.5 |
23 |
I |
3 |
| Leo Minorids (LMI) |
Oct 17-Oct 27 |
Oct 23 |
209° |
10:40 |
+37° |
61 |
2.7 |
2 |
II |
4 |
| Northern Taurids (NTA) |
Oct 20-Nov 29 |
Nov 13 |
231° |
03:52 |
+22° |
29 |
2.3 |
5 |
II |
25 |
| Leonids (LEO) |
Nov 07-Nov 28 |
Nov 18 |
236° |
10:16 |
+22° |
71 |
2.5 |
var |
III |
1 |
| Alpha Monocerotids (AMO) |
Nov 15-Nov 25 |
Nov 21 |
239°32 |
07:48 |
+01° |
65 |
2.4 |
var |
III |
4 |
| Dec Phoenicids (PHO) |
Nov 28-Dec 09 |
Dec 06 |
254°25 |
01:12 |
-53° |
18 |
2.8 |
var |
III |
18 |
| Puppid/Velids (PUP) |
Dec 01-Dec 15 |
Dec 07 |
255° |
08:12 |
-45° |
40 |
2.9 |
10 |
I |
19 |
| Monocerotids (MON) |
Dec 06-Dec 20 |
Dec 07 |
255° |
06:32 |
+09° |
41 |
3.0 |
2 |
II |
10 |
| Sigma Hydrids (HYD) |
Nov 22-Dec 23 |
Dec 09 |
257° |
08:24 |
+03° |
60 |
3.0 |
3 |
II |
21 |
| Geminids (GEM) |
Dec 05-Dec 19 |
Dec 14 |
262°2 |
07:36 |
+32° |
35 |
2.6 |
120 |
I |
26 |
| Coma Berenicids (COM) |
Dec 10-Jan 25 |
Dec 19 |
268° |
11:40 |
+25° |
64 |
3.0 |
5 |
II |
3 |
| Ursids (URS) |
Dec 16-Dec 25 |
Dec 22 |
270°7 |
14:34 |
+75° |
32 |
3.0 |
10 |
I |
5 |
Information and Table Template Courtesy The American Meteor Society, International Meteor Organization, and Meteors Online.
Shower: named for the constellation or closest star within a
constellation where the radiant is located at maximum activity.
Activity Period: the dates when the ZHR (Zenith Hourly Rates) are
equal to or greater than one.
Maximum: the date on which the maximum activity is expected to occur.
S.L.: the equivalent solar longitude of the date of maximum
activity. Solar longitude is measured in degrees (0-359) with 0 occurring at the
exact moment of the spring equinox, 90 at the summer solstice, 180 at the
autumnal equinox, and 270 at the winter solstice.
Radiant: the area in the sky where shower meteors seem to appear from.
This position is given in right ascension (celestial longitude) and
declination (celestial latitude).
Velocity: the velocity at which shower meteors strike the Earth's
atmosphere. The velocity depends on the angle meteoroids (meteors in space)
intersect the Earth. Meteoroids orbiting in the opposite direction of the Earth
and striking the atmosphere head-on are much faster than those orbiting in the
same direction as the Earth. This velocity is measured in kilometers per second.
r: The Population Index, An estimate of the ratio of the number
of meteors in subsequent magnitude classes. Simply stated: the lower the "r"
value, the resulting overall mean magnitude of each shower will be brighter. "r"
usually ranges from 2.0 (bright) to 3.5 (faint).
ZHR: Zenith Hourly Rate, the average maximum number of shower
meteors visible per hour if the radiant is located exactly overhead and the
limiting magnitude equals +6.5. Actual counts rarely reach this figure as the
zenith angle of the radiant is usually less and the limiting magnitude is
usually lower. ZHR is a useful tool when comparing the actual observed rates
between individual observers as it sets observing conditions for all to the same
standards.
Class: A scale developed by Robert Lunsford to group meteor showers by
their intensity:
Class I: the strongest annual showers with ZHR's normally ten or
better.
Class II: reliable minor showers with ZHR's normally three or better.
Class III: showers with widely variable rates. They may be strong one
year and totally inactive the next.
Class IV: weak minor showers with ZHR's rarely exceeding three. The
study of these showers is best left to experienced observers who use plotting
and angular velocity estimates to determine shower association. Observers with
less experience are urged to limit their shower associations to showers with a
rating of I to III. These showers are also good targets for video and
photographic work.
Moon: the age of the moon in days where 0 is new, 7 is first quarter,
14 is full, and 21 is last quarter. Meteor activity is best seen in the absence
of moonlight so showers reaching maximum activity when the moon is less than 10
days old or more than 25 are much more favorably observed than those situated
closer to the full moon.
Information from the "Observer's Handbook 2009" RASC
Direct download: AAGG_sky_tour_May_2009.mp3
Category: Sky Tours
-- posted at: 5:22 AM |
|
Sun, 3 May 2009
Just got back from a weekend starparty and judging event, club general meeting and hubbie's birthday. Podcast will be edited tonight and up by tomorrow!
Category: general
-- posted at: 5:47 PM |
|
Mon, 20 April 2009
Astronomy a Go Go! Don't Miss the Planets
Don't forget to step out side for evening and morning planet parade!
The occultation of VENUS by the MOON Wednesday April 22 check the IOTA website! For
occultation information for your area
Extra special is that Venus and the Moon will be in matching crescent phases!
What a treat! Get out the binos and telescope for this one set the alarm!
Mercury has been great in the evening, a real rare site for those in the high
northern latitudes. What starting tonight and for the next week as it creeps
towards the Pleiades, the new waxing crecent moon catches the group and then he
heads back down to the Sun.
Information from the "Observer's Handbook 2009" RASC
Category: Solar system
-- posted at: 5:39 PM |
|
|
