Stockton Astronomical Society
Valley Skies - January 1999 Issue
Constellations:
Taurus the Bull
Gen: Tauri
Abb: Tau
Dec: 0.1° to 30.9°
RA: 3h 20m to 5h 58m
Taurus reaches its highest point in the sky in late December, just perfect for all of the Christmas telescopes to view. It appears as a very large "V" in the sky, with the large open cluster "The Hyades" marking the bull’s nose and continuing out to form its horns. The brightest star in this area is Aldebaran, a red giant variable star that marks the bull’s eye. Aldebaran (a Tau) was named by the Arab astronomers, and means "the follower", as it seems to follow the other large cluster of this month "The Pleiades" across the sky.
The mythology for this month is really mixed up, with all my books mixing up the characters in the same story. The one thing that stays the same is that Taurus is a bull and that goes as far back as 4000 years BC. One other aspect that is the same throughout history, is that both the constellation and the bull it depicts are symbols of fertility.
The most common legend with the Greeks deals with the Island of Crete.
In this story Zeus changes into the form of a white bull. He did this to convince the Princess Europa to climb on his back and travel into the sea. They finally arrived at the Island of Crete where he revealed himself as Zeus and became her lover. Together they had a son named Minos. Minos was later to become the King of the island.
Exploring in the Bull
Follow the line of the three stars in Orion’s Belt northwest through Aldebaran. If you continue this line farther out, you will come to a large fuzzy patch in the sky. This is the open cluster M45, or the "Pleiades". These stars are also known as the "Seven Sisters" or the Seven Doves. To the American Indians, it was commonly known as the Maidens and may have been used as a test of good sight.
Several members of the Pleiad family have names. I will list them by order of brightness. The first and brightest is Alcyone (al-SIGH-oh-nee), 25 Eta Tau, at magnitude 2.87. Alcyone is the primary star in a multiple system of four stars. Its companions are about 8th magnitude and they sit in the heart of the van den Bergh 23 reflection nebula. Alcyone is also considered to be the protector of sailors, protecting them from rocks and rough weather.
Next is Atlas, 27 Tau, at magnitude 3.63. Atlas has a major role in Greek Mythology; he is the father and bearer of the heavens. Growing up, I always had the vision of him with the Earth on his shoulders.
Electra, 17 Tau, comes in third at magnitude 3.70. Electra was one of many of Zeus’s lovers and also the mother of Dardanus.
At magnitude 3.87 is Maia, 20 Tau. Maia was the first and considered the most beautiful Pliead. She was also the mother of Hermes, and the month of May was named after her. Maia is a hot young blue-white giant that is embedded in the reflection nebula NGC 1432.
Merope (MER-oh-pee), 23 Tau, is magnitude 4.18. Merope was the only Pliead to marry a mortal, and she hides her shame behind a veil. This veil is NGC 1435 and it shows the best around Merope. Look for what appears like a smudge in front of the star. Since it is most visible around Merope, NGC 1435 is sometimes called the Merope Nebula.
Taygeta ( TAY-get-a) 19 Tau at magnitude 4.30, is the primary in a wide double system. Taygeta’s companion is magnitude 8.1 and located 69 arcsec away.
The seventh brightest star in this group is Pleione, 28 Tau. Pleione is also known as BU Tau. The BU is because it is a variable star that ejects a shell of hydrogen gas, causing its magnitude to change from 4.77 to 5.5. Pleione in myths is known as the mother of the Pleiades and also as the wife of Atlas.
From the Pleiades we move to the nose of the bull, the Hyades. The Hyades is a "V" shaped cluster about 130 light-years away from us. What we see is the nucleus of an extremely large group of several hundred stars called the Taurus Moving group. There are no young blue giants in this cluster and this leads astronomers to believe that the Hyades are a much older cluster than the Pleiades. The bull’s eye Aldebaran looks like part of the cluster but it is not. It is a lot closer to us than the cluster and moving in a slightly different direction.
Travel up the eastern horn of Taurus to its end, Zeta (z)Tauri. From here we will find our last object this month. If you put Zeta on the North Eastern edge of your finder scope, you should see a fuzzy patch on the opposite side. This is the first object on Messier’s list, the Crab Nebula or NGC 1952. Messier found this nebula on September 12th 1758. It was not until 1844 when Lord Rosse was able to view its filamentary structure that it got its name the Crab Nebula.
M-1 has been studied extensively over the years both visually and with radio telescopes. The nebula is the remnant of a supernova that was seen on Earth July 4th 1054. It was so bright that it was visible during the day for 23 days. An early theory was that the 16th magnitude star in the heart of the nebula was the reason the gases glow. This has been changed by more recent studies that now indicate that the glow and the tremendous amount of energy it emits is caused by the high speed movement of electrons due to magnetic fields in the nebula itself.
There are at least two other open clusters in this constellation but the weather has not allowed me to get out and find them. They are on the Sky Atlas and if we get a clear star party night maybe we can find them together.
Clear Skies...Eric
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Lasted Updated: 11/26/2000
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