As fall approaches nights are getting longer and drier – a big plus for astronomers and fans of the night sky. The past week at Balsam have shown us what the fall skies can be with cool, dry nights and the summer milky way arching overhead.
This month the planet show picks up a notch with brilliant Jupiter once again shining over evening skies. Rising around 10 PM early in the month, by month end it will rise with the setting sun and grace the night sky all evening. A beautiful site through binoculars, you will be able to see the four bright Galilean moons (Io, Ganymeade, Europa and Callisto) on either side of Jupiter’s brilliant disk. Meanwhile Saturn sets low in the west near dusk and will disappear from view around mid-month. Mars rises around 2 AM and gradually brightens during the month. At month end it will be just beside the beautiful Beehive Cluster (M44).
If you are an early riser, this week is a good time to try and spot Mercury if you have a clear view of the eastern horizon. Its the most difficult of the inner planets to spot since it orbits very close to the Sun. Check out this article for more details.
The Autumnal Equinox occurs on September 23rd at 5:03 AM. This marks the beginning of Fall in the Northern Hemisphere and brings us equal measures of day and night.
If you go constellation hunting this month, be sure to check out Sagittarius. Drawn as an archer by the Greeks and a teapot in modern times, Sagittarius is home to many noteworthy and interesting astronomical objects such as globular clusters and nebulae. You can consult any of the numerous stargazing guides such as astronomy.com or skyandtelescope.com for pointers to the more visible and interesting objects. Sagittarius is also home to the center of the Milky Way and the massive black hole that resides there. Invisible through even the largest telescopes, we know its there none the less by its effect on the motions of nearby stars which careen wildly around an invisible object with a mass of over 4 million times that of our Sun.
Also point your eyes or binoculars straight up and take a look at Summer Triangle formed by the brilliant stars Vega, Altair and Deneb. Deneb is the ‘tail star’ of the constellation Cygnus (the Swan), Vega heads up the top of the lyre in Lyra, and Altair is the brightest star in Aquila (and the 12th brightest star in the night sky). Be sure to give a look at Alberio – the swan’s nose in Cygnus. Its actually a double star consisting of a bright yellow and a blue star in orbit around each other (see the photo below). Its easily seen in large binoculars or a small telescope. If you have visited Dogstar Observatory its on my list of objects to be seen in the summer and fall sky.
Until next month, turn out the lights and enjoy the nigh skies at Balsam Mountain Preserve.
Jim Stratigos, Resident Astronomer