Tonight, try star-hopping to the Andromeda galaxy from the constellation Cassiopeia the Queen. In a dark sky, you might even spot this hazy patch of light with no optical aid, as the ancient stargazers did before the days of light pollution.
But what if you can’t find the Andromeda galaxy with the eyes alone? Some stargazers use binoculars and star-hop to the Andromeda galaxy via this W-shaped constellation.
Cassiopeia appears low in the northeast sky at nightfall and early evening, then swings upward as evening deepens into late night. In the wee hours after midnight, Cassiopeia is found high over Polaris, the North Star. Note that one half of the W is more deeply notched than the other half. This deeper V is your “arrow” in the sky, pointing to the Andromeda galaxy.
Remember, on a dark night, this galaxy looks like a faint smudge of light. Once you’ve found it with the unaided eye or binoculars, try with a telescope – if you have one. The Andromeda galaxy is the nearest large spiral galaxy to our Milky Way. It’s about 2.5 million light-years away, teeming with hundreds of billions of stars.
Bottom line: Some prefer the constellation Cassiopedia – which is easy to find, shaped like an M or W – as a jumping off point for locating the Andromeda galaxy.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.