Cancer, the crab, is famed for its position in the zodiac. Yet other than its location, there’s not much to recommend it. The outline of the crab itself isn’t all that crab-like, and even its brightest stars are mere pinpricks of light.
Cancer’s main highlight is a star cluster known as M44. It buzzes with so many tightly packed stars that it’s also known as the Beehive. That appearance isn’t deceiving, because M44 is one of the busiest star clusters around, with perhaps a thousand stars or more.
The cluster is about 600 light-years away, and probably about 600 million years old. Astronomers deduce its age by determining the types of stars it contains — and the types it does not. Missing from the cluster are the hottest, brightest, and most massive stars. Such stars burn through their nuclear fuel in a hurry, so they disappear in tens or hundreds of millions of years, placing a limit on the cluster’s age.
Most of the cluster’s members are the faint cosmic embers known as red dwarfs, while about a third are somewhat like the Sun. Only a handful of stars are much brighter and more massive than the Sun.
M44 stands about a third of the way up the eastern sky as darkness falls on February evenings, and climbs high across the sky later on. To the eye alone, it looks like a small hazy patch of light sprinkled with a few little stars. Binoculars reveal dozens of stars, adding a bit of sparkle to the otherwise drab crab.
Script by Damond Benningfield, Copyright 2012
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