12/10/2018 – Ephemeris – How the star Procyon got its name

Ephemeris for Monday, December 10th. The Sun will rise at 8:09. It’ll be up for 8 hours and 53 minutes, setting at 5:02. The Moon, 3 days past new, will set at 8:09 this evening.

Visible low in the east at 9 p.m. or a little after will appear the star Procyon, sometimes called the little Dog Star. It’s in the constellation of Canis Minor, the little dog. It will rise at 8:40 p.m. for the Traverse City Interlochen area. Yet to rise at that time is the Dog Star itself, Sirius, the brightest night-time star. It won’t rise until 9:15 p.m., 35 minutes later even though Sirius is west of Procyon. I bring this up because the name Procyon means Before the Dog. At our latitude Procyon rises before any part of Canis Major, the big dog that Sirius is in the heart of. This is sensitive to one’s latitude. At the equator, say in Ecuador. Sirius would rise first due to its westerly position by 54 minutes. You see Procyon is also north of Sirius and that makes all the difference.

Note at 31 degrees north latitude they will rise together. Explain that, flat-earthers!

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

Addendum

Stars and constellations in the east at 9:30 p.m., about 4 hours after sunset, on December 10th. This only works for locations above 30 degrees north latitude. Created using Stellarium.