The Free Press, Mankato, MN

February 2, 2011

Starline: February 2011

By Dr. Steve Kipp
Minnesota State University, Mankato

— February is a short month but full of astronomical milestones. Copernicus, Galileo, and Clyde Tombaugh, the discoverer of Pluto, were all born in February.

Pluto was discovered February 18, 1930. And the new moon on February 3 marks the beginning of the Chinese year 4709, the year of the rabbit. In the sky Orion dominates February.

Early in the evening Orion has climbed to a position high in the south. Starting with the stars of Orion you can find a variety of interesting objects in the sky around Orion.

First find the three belt stars of Orion, all nearly the same brightness close together in a tilted line. A line through the belt stars extended downward goes just above Sirius, the brightest star in the sky excepting the sun.

If you extend the line through the belt stars upward about the same distance as Sirius, the line goes just below a bright red star, Aldebaran.

If you inspect the stars near Aldebaran you will see it is the brightest star in a small pattern of stars. This represents the horns of Taurus the bull.

In mythology, Orion the hunter is defending himself against the charge of Taurus. Many of the stars in and around the pattern are in the Hyades, a nearby cluster of stars.

In mythology the Hyades are the daughters of Atlas who holds up the  sky. The Hyades are associated with spring rain which is said to be their tears. If you continue the line through the belt stars upward just beyond Aldebaran you quickly come to a little dipper-shaped pattern of stars.

This is another star cluster called the Pleiades, the seven sisters. Although many cultures describe seven stars in the Pleiades, there are only six stars visible today. What happened to the missing sister?

Go back to Orion’s belt stars. Below the belt stars are the two bright stars that represent Orion’s feet. To the left is Saiph and to the right is bright blue Rigel. The two bright stars above the belt represent Orion’s arms or more properly Orion’s shoulders.

To the left is the bright red star Betelgeuse and to the right is the bright white star Bellatrix. Compare the stars Rigel and Betelgeuse carefully. Do you agree that Betelgeuse is red and Rigel is blue? Extend a line through Bellatrix and Betelgeuse, the shoulder stars, and continue it to the left (east).

The first bright star just below this line is Procyon, the brightest star in Canis Minor, the little dog. Once you find Procyon lift you eyes above it until you see a pair of bright stars. These stars are Castor and Pollux the twin stars of the constellation Gemini.

In Greek mythology Castor and Pollux are the sons of the god Zeus and the mortal woman Leda. Pollux was born immortal but Castor could die. When Castor did die Pollux agreed to share some of his immortality with Castor. So the brothers alternate being among the living. One walks in the world while the other waits in Hades. The constellation Gemini was important in the ancient world. Sailors associated seeing Castor and Pollux with smooth seas. The oath “by Jiminy” really was “by Gemini.”

And both Uranus and Pluto, were discovered when they were in the constellation Gemini in the sky. The moon is full February 18 and it reaches its closest approach to the Earth the next day. Consequently coastal tides, both high and low, will be extreme around that date.

By the end of February the moon will have waned to a crescent and if you inspect the southeast sky at about 6:00 a.m. you will see a brilliant Venus with a thin waning crescent moon just above it.



Send comments and questions to Steve Kipp, at steven.kipp@mnsu.edu