The Face of the Bull

Venus and Mars still appear very close together in our evening sky. Have you had a chance to see them through the clouds? It was cloudy in Peoria this weekend, so I missed the closest conjunction, but I got to see them Thursday! 

A conjunction picture shared with EarthSky.org. Image Source 

Visit EarthSky.org to see more beautiful conjunction images!

Perhaps when you were out looking for Venus and Mars, you noticed Orion, prominent in the south as soon as the Sun sets. Orion is a fantastic help in finding other constellations. If you can find Orion you can find Taurus the Bull! 

A few weeks ago, I wrote about finding Canis Major by following the line of stars in Orion's belt. You can do the same thing to find Taurus the Bull - just follow the belt stars in the opposite direction, until you find a group of stars in the shape of a 'V'. That group of stars is the Hyades (an open star cluster which contains hundreds of stars) and marks the face of Taurus the Bull. See if you can find Taurus below:

Click image to enlarge. Can you find Orion? Follow the line of stars in his belt up and to the rightto find a 'V' of stars - the face of Taurus.  Image credit: Me and Stellarium

Did you find him? If not, look below for the constellation lines to help you out: 

Click the image to enlarge. Orion and Taurus, with constellation lines. Image Credit: Me and Stellarium

The 'V' of stars (the Hyades) points up to two fairly bright stars above Orion, which represent the Bull's horns. If you keep following the line from Orion's belt through the Hyades, you will find the Pleiades, a smaller star cluster that rides on the back of the Bull.

The Hyades is an open star cluster - a group of hundreds of stars traveling though space together. The center of the cluster is about 153 light years from the Solar System, which makes it pretty close to us in astronomical terms. 

Beautiful image of the Hyades captured by astrophotographer Jerry Lodriguss. See more at astropix.com 

As you can see in the above image, many of the visible stars in the Hyades are red-orange in color, meaning they are massive stars and running out of fuel. Since all the stars in the Hyades formed at about the same time, we know that the red stars were once massive and very hot blue stars, but have used up most of their fuel. The stars that are currently blue in the cluster had less mass to begin with, and paradoxically will shine longer. 

This star cluster probably formed about 635 million years ago. Scientists believe many of the original stars in the cluster have already burnt out or escaped the gravity of the cluster. Over the next few hundred million years, the Hyades will continue to lose mass as the stars disperse and its brightest stars evolve to become white dwarfs. 

The brightest star is Aldebaran, which is actually not a part of the Hyades, as it is only 65 light years away, much closer to Earth. It is simply along the same line of sight, so it looks like it is in the Hyades from our perspective. Aldebaran is a orange giant star. Look how much bigger it is than our Sun! When the Sun runs out of fuel, it will become nearly as large as Aldebaran is now. 

Aldebaran vs.our Sun. Image Credit: Wikipedia Commons

In Greek mythology, the Hyades were the five daughters of Atlas, who carried the world upon his back. After the death of their brother, Hyas, the sisters cried so inconsolably that they died of grief (or perhaps dehydration?). They were placed in the stars, and were called the "rainy ones;" they were thought to bring spring showers. 

In another story the Hyades were nymphs who nursed the infant Dionysus (Bacchus in Rome) in their cave on Mount Nysa, feeding him milk and honey. The Romans didn't have such a romantic view of the Hyades however - they called the stars the piglets. 

Mercury Entrusting the Infant Bacchus to the Nymphs of Nysa by Boucher. Image Credit: Wikipedia Commons. 

More about the Pleiades in a future post! 

So next time you are out at night, look up! Find Orion, and use him to find Taurus the Bull. Good luck! If you want to learn more about constellations and how to find them, visit the Dome Planetarium at the Peoria Riverfront Museum. We have shows every day we are open, always included with general admission.