dipper@utastro.UUCP (Debbie Byrd) (03/08/85)
Near Regulus -- the brightest star in the constellation of Leo the Lion -- there's a star that fades from our sight. More -- after this. March 8 R Leonis The star Regulus is easy to find around now -- it's the brightest star in the constellation Leo the Lion -- now high overhead around midnight. Regulus is the bottom star in the prominent backwards-question mark pattern that represents the head of Leo. Regulus is not the only interesting star in Leo -- in fact, there's another noteworthy star near Regulus in the evening sky. This star is invisible unless you have a very dark sky -- and even then, it sometimes disappears from view. It's what is called a variable star, whose shining light varies in brilliance. Sometimes the star is bright enough to be seen with the naked eye, and sometimes -- it's not. The star is called R Leonis -- that's the letter R. It changes in brightness on an average timescale of 310 days. It's one of many known long-period variable stars, whose brightness takes a long time to change. On the dome of the sky, R Leonis lies five degrees -- about ten times the diameter of the moon -- westward of Regulus. R Leonis is too dim to see with the naked eye right now -- it passed its brightest magnitude or point of visibility last December. But in case you like colors, the star R Leonis is known for the intensity of its red light seen through a telescope. Its fiery red color is said to be sometimes tinged with purple. Script by Deborah Byrd and Diana Hadley. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin