By Bill Pellerin, Houston Astronomical Society
When you see the constellation Taurus and the nearby and popular constellation of Orion you know it’s winter. Well winter officially began at 10:44 a.m. (UT) on December 21. Those of us who live in the southern United States are now having days of cool temperatures and days of warm temperatures while the weather figures out what season it wants to be. Northerners are, according to news reports, having quite cold weather and some snow.
If it’s too cold for you to get outside and set up your telescope for an extended observing session there are still plenty of objects to admire with a quick visit to the back yard. The object this month is a very bright star, obvious to the unaided eye in the constellation Taurus. Aldebaran, a K star, stands out for both its brightness and its color, a bright orange / red that’s not duplicated by any nearby stars. To see a redder star, look to Betelgeuse, which is a M class star.
So, what are we looking at here? Aldebaran is slightly variable, from .75 magnitude to .95 magnitude, but this change in magnitude is not easily visible to anyone making visual observations. A photometric observer could detect this change, but a quick check of the AAVSO (American Association of Variable Star Observers) finds no data for this star submitted.