Archive for May 10, 2021

05/10/2021 – Ephemeris – The story of the constellations Boötes and Ursa Major

May 10, 2021 Comments off

This is Bob Moler with Ephemeris for Monday, May 10th. Today the Sun will be up for 14 hours and 38 minutes, setting at 8:58, and it will rise tomorrow at 6:18. The Moon, 1 day before new, will rise at 6:25 tomorrow morning.

Seen in the east at 10 p.m. tonight is the kite shaped constellation of Boötes the herdsman. The bright star Arcturus is at the bottom of the kite to the right. It is pointed to by the arc of the handle of the Big Dipper, higher in the east. Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young lady who had the misfortune of being loved by Zeus the chief of the Greek gods. Zeus’ wife Hera, found out about it, and since she couldn’t punish Zeus, turned the poor woman into a bear. Arcas, many years later, unaware of the events surrounding his mother’s disappearance was about to kill the bear when Zeus intervened and placed them both in the sky to save her, as Arcas still pursues her across the sky nightly.

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


Arcas and Callisto as Boötes and Ursa Major
Bootes and Ursa Major aka Arcas chasing Callisto around the pole of the sky. Created using Stellarium.
Arcas and Callisto woodcut
Arcas about to slay the bear by the 17th century artist Baur. Source: University of Virginia Electronic Text Center