Starry Autumn Sky
Learn a few constellations and you’ll have a familiar friend every clear night
Published: August 3, 2011
|Have you ever lost your way in the woods? Chances are you used two things to get around: a map and landmarks. That very same concept can help you find your way around the constellations in any season.|
The sky provides us with two major signposts each fall: The Big Dipper – a group of seven bright stars that dominates the constellation Ursa Major (the Great Bear) – and the constellation Orion the Hunter, which both play a key role in finding your way around the sky from late autumn until early spring. With the help of these two signposts, you’re well on your way to impressing your family and cabin guests with your stargazing acumen!
Exploring the Gems of Autumn
BIG DIPPER – One of the easiest star patterns to spot, the Big Dipper actually disappears from the autumn night sky for people in the South. The Little Dipper is shown at left.
Autumn’s cool nights remind us winter’s chill is not far off. Along with the cool air, the brilliant stars of the summer triangle descend in the west to be replaced with a rather bland-looking region of sky. But don’t let initial appearances deceive you. Hidden in the fall sky are gems equal to summertime.
The Big Dipper swings low this season, and for parts of the southern United States it actually sets. Cassiopeia the Queen, a group of five bright stars in the shape of a “W” or “M,” reaches its highest point overhead, the same spot the Big Dipper reached 6 months ago.
PERSEUS – This northern sky constellation is named after the mythological Greek hero Perseus, founder of Mycenae and the Perseid dynasty. He was said to have killed Medusa and rescued Andromeda from a sea monster set on her by Poseidon. As a reward, the gods placed him among the stars with Medusa's head in one hand and a jeweled sword in the other
To the east of Cassiopeia, Perseus the Hero rises high.
DOUBLE CLUSTER – These star clusters, visible with the naked eye, are part of the constellation Perseus. They are said to represent the jewels on the hilt of his sword.
Nestled between these two groups is the wondrous Double Cluster – a fantastic sight with binoculars or a low-power telescope.
Our view to the south of the Milky Way is a window out of our galaxy that allows us to look at the Local Group of galaxies. Due south of Cassiopeia is the Andromeda Galaxy (M31), a 4th-magnitude smudge of light that passes directly overhead around 9 p.m. in mid-November.
ANDROMEDA – This constellation is named after a legendary Greek princess.
M33 GALAXY – This spiral galaxy is approximately 3 million light-years away from Earth, and is one of the most distant objects in space that can be seen with the naked eye.
Farther south, between Andromeda and Triangulum, lies M33, a sprawling
face-on spiral galaxy best seen with binoculars or a rich-field
The Great Square of Pegasus passes just south of the zenith. Four 2nd- and 3rd-magnitude stars form the square, but few stars can be seen inside of it. If you draw a line between the two stars on the right side of the square and extend it southward, you’ll find 1st-magnitude Fomalhaut in Piscis Austrinus, the Southern Fish. Fomalhaut is the solitary bright star low in the south. Using the eastern side of the square as a pointer to the south brings you to Diphda in the large, faint constellation of Cetus the Whale.
GREAT SQUARE OF PEGASUS – This northern sky constellation, anchored by the Great Square, is named after one of the most well-known figures in ancient Greek mythology, Pegasus, the mighty winged horse.
|Well to the east of the Square lies the Pleiades star cluster (M45) in Taurus, which reminds us of the forthcoming winter. By late evening in October and early evening in December, Taurus and Orion have both cleared the horizon, and Gemini is rising in the northeast. In concert with the reappearance of winter constellations, the view to the northwest finds summertime’s Cygnus and Lyra about to set. |
Autumn is a great transition season, and it's definitely a fine time to experience the subtleties of these constellations.
Richard Talcott is a senior editor at Astronomy magazine. For more stories like this, visit www.Astronomy.com.