Home > Asterism, Constellations, Ephemeris Program, stars > 12/18/2014 – Ephemeris – Capella’s kids

12/18/2014 – Ephemeris – Capella’s kids

December 18, 2014

Ephemeris for Thursday, December 18th.  The sun will rise at 8:14.  It’ll be up for 8 hours and 49 minutes, setting at 5:03.   The moon, 3 days before new, will rise at 5:23 tomorrow morning.

Tuesday I talked about the bright star Capella in the constellation Auriga the charioteer,  the brightest star in the eastern sky until Jupiter rises around 9:30.  I mentioned a slim triangle of stars called the Kids, offspring of the mama goat Capella.  The star at the tip of that slim triangle is designated by the Greek letter epsilon and so in known as Epsilon Aurigae.  It was discovered to be variable in brightness in 1821.  It turns out to be an eclipsing binary, where stars eclipse each other.  Only the period between eclipses is 27 years, and the eclipses last about 2 years.  Typical eclipsing binary stars have periods of days and the eclipses last hours.  The eclipsing star has a large debris ring around it that’s also eclipsing the other star.

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

Addendum

Capella and the Kids

Capella and her kids. at 9 p.m. December 18, 2014. Created using Stellarium.

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