Long Ago Separated at Birth
This week’s moon visits two star clusters a billion years apart
Before dawn Friday morning, the moon appears just a few degrees ahead of the orange star Aldebaran, the fiery eye of Taurus the bull. To either side of the moon, you’ll find the two brightest star clusters. To the east is the Y-shaped Hyades cluster, or the face of the bull. To the moon’s west is the Pleiades cluster, or the seven sisters, which marks the bull’s shoulder.
The Hyades is the brighter of the two clusters. On a dark night you may discern a dozen or more stars with your own eyes. With binoculars or a small telescope, the number might double or even triple.
The Pleiades is the most famous star cluster, named after seven daughters of the Titan Atlas. However, even with very dark skies you’re likely to only find six of them. Myths regarding the missing seventh sister span the globe. Modern astronomers have added to the lore, having discovered that the seventh-brightest star in the cluster, Pleione, is actually a variable whose cycle from bright to dim stretches over millennia.
While appearing close and within the same constellation, the Hyades and the Pleiades are unrelated. However, scientists believe the Hyades is related to another grouping of stars, the Beehive cluster, which the waning crescent moon visits before dawn Wednesday. While the two clusters are hundreds of light years apart, astronomers suspect they were born in the same stellar incubator almost a billion years ago.
Venus is near the Beehive custer much of the week, and Wednesday before dawn the moon makes it even easier to find. Look for the moon in the east, with Venus only a few degrees to the right. Equidistant beyond Venus and near the center of the constellation Cancer, try to pick out a fuzzy blob of light. Binoculars or a small telescope will clear the haze, revealing some of the many stars in the Beehive cluster.