Bob Moler's Ephemeris Blog

Ephemeris for Monday, December 16th.  The sun will rise at 8:13.  It’ll be up for 8 hours and 49 minutes, setting at 5:03.   The moon, 1 day before full, will set at 8:07 tomorrow morning.

Last week I talked about the star Betelgeuse the bright red star in the top left of Orion’s rectangle in the hunter’s shoulder.  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 130 thousand times as bright as the sun and 74 times its diameter.  Its distance is around 860 light years.  A telescope might reveal a close companion star to Rigel, off 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.

Addendum

Taurus and Orion with Orion’s brightest stars named. Created using Stellarium.