Bob Moler's Ephemeris Blog

Thursday, January 13th.  The sun will rise at 8:16.  It’ll be up for 9 hours and 8 minutes, setting at 5:25.   The moon, 1 day past first quarter, will set at 3:15 tomorrow morning.  | A week ago I talked about the star Betelgeuse the bright red star in the top left of Orion’s upright rectangle.  Orion is seen in the southeast at 9 in the evening.  The blue-white star in Orion’s opposite corner is usually brighter.  It is Rigel whose longer Arabic name of which Rigel is the first part means Left Leg of the Giant.  Rigel is a giant itself, actually a super giant star, which is more a measure of its mass than its size, that of 17 solar masses.  Its surface temperature is more than twice as hot as the sun.  It is 85 thousand times as bright as the sun and 50 times its diameter.  Its distance is around 773 light years.  Those with telescopes might be able to spot a close companion star to Rigel, just at the edge of the bright arc light image of Rigel itself.

* Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.