dipper@utastro.UUCP (Debbie Byrd) (01/07/86)
In a moment we'll talk about two of the biggest known stars in the galaxy -- and two of the smallest. Stay with us. January 7 Big and Little Stars Some stars are much bigger than our sun -- and some are much smaller. In the southern sky this month, within the boundaries of a single constellation, there are two double stars systems -- one with two of the least massive stars in the galaxy -- and the other with two of the most massive stars. Both double star systems lie within the boundaries of the faint constellation Monoceros, the unicorn. The first double star system -- called Ross 614 -- is visible only through telescopes. It consists of two very tiny stars -- each with far less mass than our sun. The two stars are both dwarfs -- each with only about one per cent the sun's mass. The stars orbit around each other once about every 16 years. Ross 614 is only 13 light-years away -- and a good thing, too, since otherwise this little star system might have been easy to overlook from Earth. In the same region of the sky, also in Monoceros, there's Plaskett's Star -- a double system containing two of the most massive stars in our galaxy. These two stars are both very hot blue supergiants -- which whirl around each other every 14 days! The system may contain about a hundred times as much mass as our sun. Its total luminosity is greater than the sun's by about three thousand times. The system is so bright that it can be seen over a great distance of 27 hundred light-years. Script by Deborah Byrd. (c) Copyright 1985, 1986 McDonald Observatory, University of Texas at Austin