Yesterday we looked at the far side of the moon. Let’s focus on the side we can see the next couple nights. Tonight the half moon treads into Taurus the Bull, one of the few constellations that fairly resembles its mythological self. The Pleiades or Seven Sisters glimmer in the bull’s shoulder, and the Hyades trace out the its face. The twin clusters are the brightest in the sky and add spark and spangle to mid-winter skywatching.
Each hatched inside a cloud of gas and dust called a nebula. The Pleiades were born 150 million years ago during the early Cretaceous period when flowering plants made their first appearance on Earth. How fitting! The Hyades are more than 4 times as old; their arrival coincided with the appearance of early soft-bodied animals of the Ediacaran Period, long before the first fish swam. Each now travels as a gravitationally connected stellar swarm around the Milky Way galaxy’s hub.
If you have clear skies tonight the two clusters and moon will form a neat equilateral triangle about 12° or a little more than a fist on a side. Because the moon will be a little bright, the clusters will look more appealing in binoculars. By the way, the bright star Aldebaran doesn’t belong to the Hyades. It only appears that way because it’s in the same line of sight as the cluster. Aldebaran shines in the foreground just 65 light years away compared to 151 light years for the Hyades. The Pleiades are more distant at 444 light years.
Wednesday night (Feb. 12), the moon will shine squarely within the Hyades, making for a very cool sight in binoculars. I do hope you get to see it. Go out and look anytime it’s dark. Like people drawing close to fire to stay warm, the little Hyades stars will gather round the moon. Can you still see Aldebaran with the moon so close? While you’re enjoying the view through binoculars, there are three double stars staring right back at you. All three are easy “splits” in any glass. Two of them — Theta (θ) Tauri and Sigma (σ) Tauri — are called optical doubles because like Aldebaran, they’re in the same line of sight and only appear close. Unlike Aldebaran both are true cluster members. The third pair, Delta1,2 (δ1,2) Tauri is a true double star and both suns are super easy to see.
Clear skies and happy hunting!