Home > Ephemeris Program, stars > 04/26/2016 – Ephemeris – Arcturus, just passing through

04/26/2016 – Ephemeris – Arcturus, just passing through

April 26, 2016

Ephemeris for Tuesday, April 26th.  The Sun rises at 6:39.  It’ll be up for 14 hours and 2 minutes, setting at 8:42.   The Moon, 3 days before last quarter, will rise at 12:48 tomorrow morning.

Arcturus is an orange-colored giant star, 37 light years away.  We see it high in the east and pointed to by following the arc of the handle of the Big Dipper.  Arcturus is a rapidly moving star.  It’s velocity is about 76 miles per second (122 km/s).  It’s almost at its nearest to the Sun now.  In the next 2,000 years it will move about one degree, twice the width of the Moon toward Spica.  Arcturus may be part of a dwarf galaxy being assimilated by the Milky Way which may account to its odd motion.  Arcturus is thought to be close to 8% more massive than the Sun and about 6 to 8 ½ billion years old.  It has entered its red giant stage after running out of hydrogen in its core.  It may be a glimpse of what the sun will look like in 5 billion years.

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


Arcturus in motion.

The constellation Bootes and the 4th brightest star in the night sky. The thin line extending to the right from Arcturus is the distance it will travel in the next 2,000 years. That line is nearly one degree ling, or 2 Mon diameters. Created using Cartes du Ciel (Sky Charts)

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