Astronomy From Your Back Yard - 6/2 to 6/8 2010
Wednesday, June 02 2010 @ 03:37 pm EDT
Contributed by: dgrosvold
By Dave Grosvold
From our vantage point right now in the evenings, the Big Dipper asterism is upside down. Look above the three stars of the handle for Canes Venatici, the Hunting Dogs. This week, you can catch several bright galaxies in this area high overhead in binoculars. These Messier galaxies, named for the first astronomer who cataloged them, Charles Messier (pronounced ME-see-ay,) are challenging, but attainable. Grab a chaise lounge chair, a pair of binoculars, lay back, and spend some time scanning this area. Itís easiest to hunt out M63, M94, and M106, but M51, the Whirlpool Galaxy, is the most famous of this group, and the most difficult to spot due to its low surface brightness. Consider yourself more than a beginning observer if you can bag this one. You can view a finder chart for these galaxies by clicking on the chart thumbnail image.
Starting on Thursday evening, Mars is within 3° of Regulus in the constellation Leo. They're almost the same brightness, and make a striking color-contrast pair high in the west after dark. Follow them each evening until they reach conjunction on Sunday, June 6th, when they will be only 0.8° apart.
On Friday evening, June 4th, the Moon reaches Last Quarter at 5:13 PM CDT. The Moon doesnít rise Friday evening until 1:00 AM or so, which gives observers a few hours of dark sky observing before it comes up and washes the sky in moonglow.
The bright Evening Star shining in the west-northwest during and after twilight is Venus. The twins of Gemini, Pollux and Castor, are above it. Venus is about as high in twilight as it will get this year in this part of the world. Venus is still a small gibbous disk in a telescope. It's so dazzlingly bright that you'll have the best telescopic views of it in the bright blue sky before sunset when the contrast is lower. After sunset, you may want to use a polarizing or neutral density filter to cut the glare. Later in the summer, Venus will be closer to Earth, and easier to view when larger and in its crescent phase.
Also this week, the faint comet C/2009 R1 (McNaught) is nearing its period of best visibility in mid-June at magnitude 7.8. Look for it low in the northeast just before the start of dawn with binoculars or a small telescope.
If youíre up to it, Saturday and Sunday morning just before dawn is a good time to catch the Moon and Jupiter rising together in the eastern sky. Just below the Circlet of Pisces, Jupiter climbs higher each week in the east-southeast during the early dawn hours. Donít forget to try looking for Jupiter's Great Red Spot while the South Equatorial Belt is nearly invisible. Mercury can also be found very low in the east at dawn. Look for it with binoculars, below Jupiter and to the lower left.
Saturn glows high in the southwest during the evening this week. In a telescope, Saturn's rings are tilted a mere 1.7į from edge-on, their minimum tilt for the next 15 years. Look for the thin black shadow-line cast by the rings across Saturn's bright globe.
The ISS (International Space Station) will make several overhead passes during the early morning hours this week. The brightest of these will occur on Sunday and Tuesday mornings, both near magnitude -3.5. On Sunday morning, look for the ISS to rise in the SW at 5:31 AM, and pass overhead at a maximum altitude of 83° at 5:33 AM in the SE before setting in the NE at 5:36 AM. A bit earlier on Tuesday morning, the ISS will rise at 4:44 AM in the SW, reach a maximum altitude of 82° in the SE at 4:45 AM, and then set in the NE at 4:48 AM. The ISS will also make passes on Saturday and Monday mornings but will only reach a maximum brightness of magnitude -1.3 on these passes.
There will also be several bright Iridium Flares this week in the early morning hours, with several reaching fairly bright magnitudes. But if youíre out and about in the evening on Thursday, June 3rd, try to catch Iridium 18 at an altitude of 63° in the eastern sky at 9:06 PM.
Check the Heavens Above website for times and positions of Iridium Flares, the ISS, and other satellites in the nighttime sky. You can also view a current finder chart for comet C/2009 R1 (McNaught) on the Heavens Above website.