Starwatch: Stargazing is really heating up this fall
Where has summer gone? We're hearing the swan song of summer loud and clear; the Minnesota State Fair is on, schools are opening, and I even spotted a few Halloween decorations going up in a department store.
If you're like me, you hang on to summer as long as you can, and one way to do that is September stargazing. There are still plenty of summer constellations playing on stage in the celestial theater over Rochester, and being that it gets darker earlier, your sleep deprivation is reduced.
As soon as evening twilight sets in, the first star that pops out in the west is not a star at all. That's the planet Venus, which is about 100 million miles away.
As bright as it is, Venus isn't very interesting through a telescope, even a big one. That's because it's completely shrouded in a poison cloud cover. About the only interesting thing about observing Venus is that it goes through phase/shape changes like the moon. Right now Venus is ovalish, like a gibbous moon.
Not far away is the much fainter planet Saturn. Even through a good telescope, Saturn will be small and very fuzzy. It's a heck of a long ways away at well over 900 million miles, and because it's so low in our sky, the atmosphere really blurs it out.
In the low southern sky is one of my favorite constellations, known by many as the Teapot. Now, for you purists, the teapot is formally known as Sagittarius, a centaur shooting an arrow at its neighboring constellation to the west, Scorpius the Scorpion. If you see Sagittarius as a half man, half horse with a bow and arrow, more power to you! I'll stick with the Teapot.
The Teapot is located in the direction of the center of our Milky Way galaxy, around 30,000 light-years away. If the sky is dark enough where you are, you'll see a milky white band of light from the Teapot in the southwest sky that runs all the way across to the northeast horizon. You're looking at the combined lights of billions of distant stars that make up the main plane of our galactic home.
Nearly overhead is another signpost of summer, the Summer Triangle. Just look for the three brightest stars you can see around the zenith and that's it. All three stars are the brightest stars in each of their respective constellations. Vega is the brightest star in the constellation Lyra the Harp. Altair is the brightest in Aquila the Eagle, and Deneb is the brightest star in Cygnus the Swan, also known as the "Northern Cross."
There's nothing really all that "summer" about the Big and Little Dippers, since they're visible every night of the year, but summer is a great time to spot them. That's especially true for the Big Dipper, since it's proudly hanging by its handle high in the northwest. The fainter Little Dipper is standing on its handle to the right of the Big Dipper, with Polaris, the North Star, at the end of its handle.
In the northeast sky, look for the sideways "W" that outlines the throne of Cassiopeia the Queen. Just to the upper left of the queen in the northern sky, look for the faint upside-down house with the steep roof, which is supposed to be Cepheus the King.
You can't deny the change in seasons forever. Autumn is coming, with the possible snow season beginning on Sept. 15. One of the prime autumn constellations, Pegasus the winged horse, is on the rise in the eastern sky after sunset. Look for the big diamond of stars that outlines the torso of Pegasus. This is called the "Square of Pegasus," but because of the way it's positioned in the sky this time of year, it's also known as the "Autumn Diamond."
Below and to the left of the Autumn Diamond, scan with a decent pair of binoculars for a faint patch of light. If you see it, you are looking at our galaxy's next-door neighbor, the Andromeda Galaxy, more than 2 million light-years away. Keep in mind that just one light-year equals almost 6 trillion miles!
A comet is coming
Later this year the brightest comet in a long time could really light up our skies. Comet Ison is now about halfway between the planets Jupiter and Mars and will pass by the Earth and Sun in late November and early December. Forecasting the brightness of comets is always tricky, but right now indications are that it could have a really long tail and be bright enough to see with the naked eye. Stay tuned to this column for more in the coming weeks.
Instructions for sky map
Cut out the map. Hold it over your head and line up the compass points on the map with the points on the horizon. Use a small flashlight with a piece of red cloth or paper over the lens to protect your night vision.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul and is author of the book, "Stars, a Month by Month Tour of the Constellations" published by Adventure Publications.
The Rochester Astronomy Club welcomes new members and puts on public star parties. Their website is www.rochesterskies.org.
If you have any astronomical questions or want me to write about something you're seeing in the night sky, drop me a line at email@example.com.