Archive for August 29, 2019

08/29/2019 – Ephemeris – To astronomers constellations are just areas of the sky

August 29, 2019 Comments off

Ephemeris for Thursday, August 29th. Today the Sun will be up for 13 hours and 23 minutes, setting at 8:25, and it will rise tomorrow at 7:02. The Moon, 1 day before new, will rise at 7:00 tomorrow morning.

What are constellations? I talk about them all the time on this program. There are 88 officially recognized constellations by the International Astronomical Union. Most, in the northern sky come from the ancient Greeks, and are given Latin names. For professional astronomers the constellations mark out specific areas of the sky in an interlocking set of puzzle pieces. In some cases it looks like there’s some gerrymandering with the shapes. Some star to star lines drawn do seem to represent the namesake, like Scorpius the scorpion. Most don’t. Stars of a constellation generally are not near one another, they’re just in the same direction from us. Asterisms, or informal star groups, like the Big Dipper however do look like what they represent.

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


Summer constellations showing stars, lines, boundaries, and figures in succession. Click on the image to enlarge. Here you can see that Jupiter is in Ophiuchus, not Scorpius. Created using Stellarium and GIMP.