Wednesday, April 28 2010 @ 07:01 PM CDT
Contributed by: dgrosvold
By Dave Grosvold
The Moon is just past Full this evening, which occurred at 7:18 AM CDT. Tonight the Moon rises at 8:42 PM CDT, which washes out most of the eastern and southern skies. It is also too bright at or near Full to view through a telescope or binoculars, unless you have a filter. However, the Moon does look great when Full and viewed with the unaided eye.
One thing you can catch even with a Full Moon will be the brightest pass of the International Space Station (ISS) this week at -3.3 magnitude (Mag.) The ISS passes overhead starting at 9:18 PM CDT. It will swing from an altitude of 10° in the SW, up to 82° in the NW, then sink to 11° in the NE before becoming invisible. Look for the ISS to reach its brightest high overhead in the northwest.
Mars is also high overhead, but now dimming in Cancer as it pulls away from the Earth. Mars is still east of the Beehive Cluster. Jupiter is rising just before dawn in the eastern sky. At this time of the morning, Jupiter is brightest object in the sky.
Thursday, April 29th
Look to the lower left of the Moon tonight after 11 PM or so for rising Antares. Antares (an-TAR-eez) is a bright red supergiant star in Scorpius, with an approximately 800 times larger radius than our Sun. But Antares is a cool, low density star, with only about 18 solar masses, and it radiates most of its energy in the infrared part of the spectrum. Antares resides about 600 light years from our Solar System.
Catch the ISS again this evening at 8:44 PM CDT, starting at 10° in the S, going up to 24° in the SE, then back to 10° in ENE. It stays low in the sky this evening and shines a bit less bright at only -2.1 Mag.
Many members of the Virgo Cluster of Galaxies can be spied in binoculars on a good dark, moonless night. This area in Virgo is home to a huge group of galaxies, which are part of our own Local Supercluster. Tonight you have a chance to see many of them before the Moon rises, just before 11:00 PM. Look for very faint fuzzy splotches slightly bigger than stars. Stars will always appear as a point source in binoculars or a telescope, but extended objects like galaxies and nebula will appear to be larger than points, sometimes much larger. In a medium amateur telescope (10” or so,) there are enough galaxies visible in this part of the sky to keep you busy most of the night.
On Friday evening, the ISS passes low in the north but brighter than the last one at -3.1 Mag, starting at 8:34 PM CDT, look for it at 10° in the NNW. It will be hard to spot this time since it won't get more than 10° above the horizon.
Venus is near the Pleiades low in the western sky all week. The Pleiades or M45, is a nearby region of recent star formation, and so is full of hot, young, blue-white stars.
On Saturday evening, look ¼° to the lower left of Venus in binoculars for Kappa Tauri — a binary star in Taurus. You should be able to discern both components of the binary pair in binoculars. Whether you realize it or not, most star systems are binary stars. As a single star, our Sun is an exception, not the norm.
Sunday, May 2nd
You can catch Iridium Flares on Sunday, Monday, and Tuesday evenings. On Sunday morning, Iridium 96 flares to -7 Mag at 6:04 AM CDT, Look for it at an altitude of 27°, in the north-northeast.
Saturn is high in the south at the head of Virgo all week. Look for fine black shadow of rings on disk of planet in telescope or binoculars.
On Monday evening, Iridium 56 flares to -8 Mag at 9:43 PM CDT. It should be visible at an altitude of 49° in the eastern sky. Remember, Iridium Flares are brief and not something that will be visible for more than a few seconds. The flare Monday night will be the brightest one visible this week.
Tuesday, May 4th
On Tuesday, you have two chances to see an Iridium Flare. In the morning, Iridium 29 flares to -3 Mag at 5:47 AM CDT, 21° high in the north-northeast. In the evening, Iridium 84 flares to -2 Mag at 9:37 PM CDT, at an altitude of 49° in the eastern sky.