Starwatch: A beehive, a manger, and two donkeys point to spring
Even though the weather may not exactly be advertising spring, nothing can stop it astronomically. The vernal equinox is next Wednesday afternoon at 4:58 p.m. For the first time since last September, the sun is entering the northern half of the celestial sphere. From now until late June, the sun will climb even higher in the sky until the days reach their maximum length.
Already there have been many signs in the night sky for some time now. One of those signs is the Beehive star cluster. It’s far from a celestial billboard, but it’s a definite sign of warmer times to come.
The Beehive star assemblage is located in the very faint constellation Cancer the Crab. Finding Cancer is one of the ultimate stargazing challenges unless you’re really in the dark countryside. The Beehive cluster is actually brighter than most of the stars in the constellation it’s part of. Look in the southeastern sky about halfway between the brighter constellations Leo the Lion and Gemini the Twins.
The Beehive cluster is known astronomically as Messier object 44, or M-44 for short. What most folks see resembles a patchy faint cloud. When ancient Greek astronomers like Hipparchus observed it around 130 B.C., he registered it in his star catalogue as a “cloudy star.” The Romans saw it as a manger and called it Praesepe, which is Latin for manger.
In those days the Beehive’s host constellation, Cancer, was known to some cultures as a pair of donkeys. The tale spun down that the ghostly cloud was a manger that the beasts were feeding at. The donkeys and the manger were also a way to forecast the weather. It was said that a “murky manger” was a sign of rain. As much as I like natural weather forecasting in my daytime job, I won’t be trading in computer models, satellite pictures, or doppler radar for a pair of asses feeding at a manger anytime soon.
It wasn’t until the early 1600s, when Galileo poked his telescope toward the Praesepe and saw it as a cluster of stars, that it eventually got the name Beehive cluster. With your not-so-crude telescope, or even a decent pair of binoculars, you can easily see how it got that moniker.
Astronomically the Beehive is considered an open star cluster, a group of about 1,000 stars that have emerged out of the same nebula as hydrogen gas sprinkled with heavier elements from a long since-exploded star. The stars in this cluster are believed by astronomers to be about 500 to 600 million years old, and while that may be considered a young age for a star, it is rather old for a cluster of young stars. Many of these same kinds of clusters are gravitationally broken up before the stars are that old, but the Beehive is hanging in there. That “teenage mob” of at stars is over 3,400 trillion miles away from our backyards, and nearly 134 trillion miles wide.