September 2013 Sky from the Keeble Observatory
Lunar phases for September: New Moon on the 5th, at 7:36 am; First Quarter on the 12th, at 1:08 pm; Full Moon on the 19th, at 7:13 am, and Last Quarter on the 26th, at 11:56 pm. Fall Equinox on the 22nd – Sun crosses equator at 4:44 pm.
Early risers will find Mars and Jupiter in the predawn twilight. Both are to the east, with Mars below and a bit to the left of Castor and Pollux, and Jupiter above and to the right early in the month. That bright star to the southeast is Sirius, which is bright enough to be mistaken for a planet. That they are to the west of the Sun tells us that we are catching up to them as we make our way along our orbit. They’ll both climb as the month goes on. Jupiter ends the month southeast at dawn. Evening twilight finds Venus and Saturn to the west. Their cosmic ballet will have them switch places by month’s end.
Our mid-month view of the sky, about two hours after sunset, finds Cygnus (the Swan) at zenith, appearing to glide along the Milky Way from northeast to southwest. The bright star Deneb marks the tail of the swan, about ten degrees northeast of zenith. At a similar angle to the west we see brilliant Vega in the constellation Lyra. These two bright stars make a triangle with Altair, about 30 degrees south of zenith. With binoculars, on a clear dark night, just east of Deneb you may find the ghostly, familiar outline of the “North America Nebula. Cassiopeia is to the northeast, looking like a W tipped backwards. If you follow the line of the “left” side of the W toward the east you’ll notice the faint fuzzy patch of the Andromeda Galaxy, about 45 degrees above the eastern horizon. It’s best seen on a clear, moonless night, and best by “averted vision” without binoculars. That you can see it at all gives some sense of the scale of our Universe, since this is the most distant object visible to the naked eye. It’s practically in our back yard! This spiral galaxy is only 2.2 million light years away, and is on a collision course toward our home Galaxy … it will be “here” in about 5 billion years, roughly when the Sun becomes a red giant!
Copyright 2013George Spagna