With autumn in full swing, it's a great time to round up the family, a telescope or pair of binoculars, and a basic star chart to check out some of this season's spectacular celestial showpieces. All are easy targets for binoculars or a small telescope and well worth coming back to again and again.
Every beginning stargazer should start right here, with the Moon. Because not only is it the easiest space object to find, it is also arguably the most fascinating, with myriad surface features to explore. The best time to view the Moon is when it is in a partial phase, not when it is full or nearly full. Why? Because when it's full not only is it overpoweringly bright, but also the Sun's light is hitting the lunar surface head-on, casting no shadows. It's that shadow relief along the border between the light and dark portions of the Moon's face in the partial phases that really highlights the rugged detail of the crater walls and mountain peaks.
As a guide to your Moon viewing, we highly recommend Orion's new MoonMap 260! It features 260 named lunar features and locations of all lunar spacecraft landings.
The giant planet Jupiter is a must-see target this fall. By November it can be found fairly high in the sky by midnight or earlier in the constellation Gemini. Virtually any size telescope will show Jupiter's four largest moons, whose positions change nightly. On Jupiter's orb itself, see if you can discern its cloud bands, which exhibit a range of different hues. Even more difficult is making out the Great Red Spot, which typically requires a mid-size telescope or larger.
Albireo (Beta Cygni)
While observing double stars may not be everyone's cup of tea, this is one you just have to see. It is surprisingly picturesque. Located at the head of Cygnus the Swan, it consists of two gravitationally bound stars that display a striking color contrast in the telescope's eyepiece. The brighter, 3rd-magnitude star is gold while the other, a 5th-magnitude sun, glows blue. The color difference looks even more pronounced if you defocus the stars slightly.
M31, taken by Bryan Cogdell, taken with an Orion ED80T CF Triplet Apochromatic Refractor Telescope, and Canon 250D.
The Andromeda Galaxy (M31)
Look for this majestic spiral galaxy in the eastern sky. If your sky is dark enough you will be able to make out M31 as a distinctly fuzzy patch with just your eyes. The diffuse light from its billions of stars fills the eyepiece of any telescope. Use low power for the clearest image. You'll see a star-like center and maybe even a dark dust lane. The galaxy looks wonderful in binoculars, too. You are seeing the galaxy as it was 2.4 million years ago, which is how long it has taken its light to reach Earth! Ancient light, indeed.
The Pleiades (M45)
One of the most beautiful star clusters visible with the naked eye or wide-angle binoculars is the Pleiades, or "Seven Sisters." Look for this bright, dipper-shaped open cluster in the eastern sky. Binoculars will reveal dozens of stars in this grouping spanning nearly 2 degrees, or four Moon diameters. With a telescope, use the lowest magnification possible for the widest field of view. In a dark sky your telescope may start to reveal some fuzziness, i.e., nebulosity, around one or more of the brightest stars.
Near the "W" of Cassiopeia resides a pair of open star clusters called the Double Cluster. They are a beautiful sight in binoculars and small telescopes. The twin splashes of bright, mostly white and blue-white stars span the width of two full Moons, so a wide-field instrument and low power will show them best. There are also a few yellow-orange stars sprinkled in among the others. Can you spot them?
M15 Globular Cluster
You'll find this tight ball of stars just northwest of the bright star Enif in the constellation Pegasus. M15 gets its moniker from being the 15th entry recorded by 18th century French comet hunter Charles Messier in his now-famous catalog of deep-space objects. M15 is one of the fall season's finest globular clusters. In binoculars it will look like a fuzzy spot, but in a 4" or larger telescope you'll start to resolve pinpoint stars around its edges. It's hard to believe that so compact a cluster contains about 100,000 stars, but it does!
There are plenty more great objects gracing the fall skies. So get out and enjoy the season's celestial scenery.
What is your favorite object to view this time of year? Tell us in the comments!