Sep 01

September 2009

What’s Up in the Sky September, 2009
By Peter Burkey

Some of the best observing in West Michigan often occurs during the month of September. The nights are usually mild, bug-free, and clear and kids do not have to stay up past their bedtime waiting for it to get dark. So, make an effort to do some star gazing this month – conditions may not be as favorable until next Spring.

Jupiter’s moons continue to put on quite a show, as I described last month, transiting, eclipsing, and being occulted by the planet and each other. Google “Jupiter’s moons September 2009” for specific dates, times, and observing suggestions.

One of the easiest astronomical observations is the “Stonehenge” sunset. This occurs on the first day of Autumn and Spring, when the Sun sets due west. Standing beside any east-west road (such as 8th Street) you will witness the Sun setting on the horizon at the very end of the road and, depending on your exact location, it may be peeking between buildings or stands of trees. Observe again after two or three days to see just how quickly the Sun’s position changes at this time of year.

Early risers can enjoy seeing the planet Venus dazzling the Eastern predawn sky. Don’t miss a beautiful pairing of the planet and a thin crescent Moon one hour before sunrise on Wednesday, September 16. On the 20th, look for Venus and the star Regulus separated by less than the width of a full Moon.

This is also the time of year when the Summer Triangle is nearly overhead and the Milky Way stretches from the spout of the “teapot” in Sagittarius in the South all the way to the “W” shaped Cassiopeia in the North. Scan it with binoculars or a small telescope to reveal star clusters and nebulae.

One of my favorite telescopic targets is the beautiful double star Albireo. It is head of the Swan, Cygnus, (or the bottom of the Northern Cross) and is about half way between Vega and Altair, almost overhead.

Take advantage of this time of year to enjoy what’s up in the sky.

This month in history:
Sept. 3: Last two lunar landings canceled by NASA – 1970
Sept. 6: Space Shuttle Challenger makes first night landing – 1983
Sept. 8: Premier of “Star Trek” – 1966
Sept. 18: Photo of Earth and Moon together in space taken by Voyager 1 – 1977
Sept. 21: Galileo spacecraft plunges into Jupiter’s atmosphere, ending mission – 2003
Sept. 23: Premier of “The Jetsons” – 1962

Here are this month’s viewing highlights:
Planets this month: Jupiter is visible in SE at sunset and is the brightest object in the southern sky as the night progresses. Venus dominates predawn sky in the east, rising two hours before the Sun. It is next to a thin crescent Moon on the 16th – not to be missed. Mars is 33 degrees to the upper right of Venus, in the constellation Gemini. Mercury and Saturn join Venus by month’s end.

Sept. 4: Full Moon
Sept. 11: Last-quarter Moon
Sept. 18: New Moon.
Sept. 22: Autumnal equinox – first day of fall in Northern Hemisphere.
Sept. 26: First quarter Moon.