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 Information
As 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 April 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!
April Morning Planets
(click images to enlarge)
Beginning of the month
April 21st
- Mercury- In superior conjunction on March 31st look for Mercury at its greatest elongation east on April 26th. This will be the Northern H. best view all year. Look just between the waxing crescent Moon and the horizon just after sunset -2.1 mag (1st) to -0.4 mag (21st)
April 26th
- Venus- Just stunning in the morning sky growing to -4.7 after mid month. Watch for the lunar occultation starting just around sunrise and ending about an hour later! Large binos and small telescope should catch the action! -3.9 mag (1st) to -4.4 mag (21st)
Venus just before sunrise passing behind the Moon....and later, after sunrise, reappearing
- Mars- Finally starts to get brighter and over the next few months Mars will run (almost) a circle around Venus as their positions change in relation to Earth. This little game of tag within the constellations will be fun to watch for the next several months. 1.2 (1st) to 1.2 mag (21st)
- Jupiter- Should be high enough in the morning to be seen. (unless you are in Seattle and we have our perpetual planet zapping cloud banks) Look for Jupiter during the day on the 19th as the Moon passes close by. On the 26th pull out the telescope and see if you can catch the "fake moon" mag 5.9 44 Capricorni -1.9 mag (1st) to -1.9 mag (21st)
- Saturn- In eastern Leo Saturn's rings are inclined 3.8 deg towards Earth. Definitely a dramatic difference from last year! 0.6 mag (1st) to 0.6 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 April 2009
Days and Times in UT: (help with time)
Observations are for 9 pm for everyone!
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 - April 2009
| 2-5 | - 100 Hours of Astronomy! AAGG will be at the Museum of Flight in Seattle (look for the TAS Student booth). To find an event near you go to the 100 Hours of Astronomy Website! |
| 2 | - First Quarter Moon (14:34 UT) |
| 4 | - Moon 1.7 deg S of Beehive (M44) in Cancer |
| 6,22 | - Saturn lunar transit event - Mimus eclipses Enceladus (get custom times for your viewing site from SkyCal (also Enceladus and Tethys on the 17th) (use the Saturn applet to find Enceladus) |
| 7 | - Moon 6 deg N of Saturn in Leo |
| 9 | - Full Moon (14:56 UT) |
| 10-18 | - Zodiacal light possible low on the north-northwest horizon (NH) |
| 13 | - Antares 0.4 deg S of Moon possible occultation in your area. |
| - Double shadow transit on Jupiter (16:56 UT) |
| 15 | - Mars 0.5 deg S of Uranus |
| 16 | - Moon at apogee (404232 km) |
| 17 | - Last Quarter Moon (13:36 UT) |
| 18 | - Venus 6 deg N of Mars |
| - Eta Aquariids meteor peak - persistent long tail meteors leftovers from Halley's Comet! Unfortunately there is likely to be interference with the Moon |
| 19 | - Jupiter 2 deg S of Moon |
| 20-26 | - National Dark Sky Week - turn off unnecessary light, change out bulbs to energy efficient low watt bulbs, install motion detectors....do something! :-) |
| 22 | - Lyrid meteor shower peak -Not one of the strongest annual showers but should be a good show with very little Moon (3 days until new) leftovers from Comet Thatcher look for ~12 meteors per hour |
| - Venus 1.1 deg S of Moon! possible occultation in your area. |
| - Mars 6 deg S of Moon |
| 25 | - New Moon (3:23 UT) |
| - Mercury 1.9 deg S of the Moon and the Pleiades (M45) in Taurus |
| 28 | - Moon at perigee (366040 km) |
| 29 | - Moon 1.8 deg N of M35 in Gemini |
| - Don't forget to visit the International Year of Astronomy Website for a plethora of fantastic activities, events and ideas! |
| - Venus at its brightest for the month, -4.5 mag |
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 we will look for 10 objects, 8 open clusters in the southern milky way and a pair of galaxies, all are within reach of binoculars. The open clusters are easy binocular targets and most are visible with the naked eye. M81 and M82 are difficult binocular targets that offer a stunning telescopic view. (I'm trying to find out what has happened to the NGC/IC Project homepage. It has been a standard AAGG reference for 3 years but seems to have disappeared! If you have any information on this great site please let me know....until then the images will be from: "Messier45.com" )
- M41
- This cluster in Canis Major is visible as a hazy patch to the naked eye just below Sirius. M41 is resolvable in binoculars and appears fairly loose in telescopes at low power.
- M93
- This is a small fuzzy patch of light in Puppis, partially resolvable in binoculars. The hardest part of finding this cluster in binoculars is picking it out of a fairly rich region of the milky way. Use low power to examine this cluster and the surrounding richness in a telescope. Medium power provides a nice view of the cluster itself.
- M47
- A bright cluster in Puppis, easily visible as a hazy patch to the naked eye. Binoculars will show a large hazy patch with many stars resolvable. Telescopes show a fairly loose cluster with stars of wide variety of magnitudes.
- M46
- This cluster is right next to M47 and is also visible to the naked eye. In binoculars M46 appears as a large hazy patch with no stars resolvable, giving a nice contrast to M47. In telescopes at low powers this cluster evenly fills the eyepiece. While you are here go to medium or high power and look for the planetary nebula NGC2438. It will appear as a faint uneven ring, with a blue/green color.
- M50
- An open cluster in Monoceros. This is a small hazy patch in binoculars, partially resolvable. Like M93, the richness of the surrounding field is the only difficulty in finding this object. This is a fairly tight cluster at low power in a telescope.
- M48
- Moving on to Hydra, we find another naked eye cluster. M48 is a large fuzzy patch in binoculars, partially resolvable. Use low to medium power in your telescope for a spectacular view.
- M67
- In the southeast portion of Cancer is another open cluster, barely visible as a fuzzy patch to the naked eye. Binoculars show M67 as a large hazy patch of light, similar to M46. Use low power to resolve this large, rich cluster in a telescope.
- M44
- Known as the Praesepe or Beehive Cluster, this open cluster is easily visible to the naked eye as a large, fuzzy patch bigger than the moon. Binoculars or rich field telescopes provide the best view of M44.
- M81, M82
- This pair of galaxies in Ursa Major are very possible to see in binoculars, they look like a pair of fuzzy stars. Both galaxies will fit into the same low power telescope field. M81 will appear as a large oval gray patch of light. M82 is a pencil like streak of light next to and perpendicular to the long axis of M81.
From the Tony Cecce, Corning, NY - Twelve Month Tour of The Messier Catalog
Comets for April 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 hat
or write us a favorable review in iTunes of Podcast Pickle or iPodder!
Music Scottish Guitar Quartet -"Romance Within You"
Marqui Adora- "Catch the Sun"
Sean Wiggins- "Mercury in Retrograde"
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
