Bob Moler's Ephemeris Blog

This is Ephemeris for Friday, September 12th. Today the Sun will be up for 12 hours and 39 minutes, setting at 7:58, and it will rise tomorrow at 7:19. The Moon, 2 days before last quarter, will rise at 10:19 this evening.

The constellation of Cassiopeia the queen looks to most of us like the letter W. However, since it is circumpolar, that is it seems to move around the North Pole of the sky without setting. It represents to us with various orientations. When it’s seen now in the evening in the northeast, it kind of looks like a misshapen number 3. In early winter it would be nearly overhead and be the letter M, not the University of Michigan block letter M, but the angular University of Minnesota M. In early spring, it’s in the northwestern sky as the Greek capital letter sigma. And finally in early summer it’ll be low in the north and become the upright letter W. I’ll return to Cassiopeia and tell her story later this autumn.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.