Three Red Giants

We are once again working in daylight saving time. The sun rises before 7:37 a.m. and sets after 7:33 p.m. The daylight and nighttime periods are equal on March 17 when the Sun rises at 7:33 a.m. and sets at 7:33 p.m. Spring begins on March 19 at 11:06 p.m.

On March 14, look for the Moon just below the Pleiades Star Cluster. Use binoculars to view this nice pairing and the surrounding area low in the southwest at sunset.

We turn our attention to three large red giant stars that are all visible at 11 p.m. Two of these beacons are low on the horizon so they tend to twinkle and flash colors. Compare the color you see when viewing these stars with the color of other stars.

The stars are red giants because they are significantly larger than the Sun. The Sun is 865,000 miles in diameter. The red comes from the fact that the stars appear red or at least orange when view with a telescope. This is because they are cooler than the Sun and glow with a reddish light.

We start low in the west with Aldebaran in the constellation Taurus the Bull. Aldebaran sits at the top left leg of a “V” shaped cluster of stars called The Hyades.

It marks the eye of Taurus. Aldebaran is 37 million miles in diameter.

From Aldebaran, move to the left to the three stars in a row that form Orion’s Belt hanging low in the westsouthwest. Move up from the belt to the bright red star Betelgeuse in Orion. This object is 600 million miles in diameter and it will explode as a supernova within 100 thousand years.

Now, face east no earlier than 11 p.m. Low in the east is our final red giant known as Arcturus in the constellation Boötes (bo-OAT-eez) the

Herdsman. Boötes looks like a large diamond shaped kite lying on its left side. Arcturus is the smallest of our giants at only 21 million miles in diameter.

These three red giants are always interesting to observe.

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