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05/21/2020 – Ephemeris – A star cluster in a most unusual spot

May 21, 2020 Leave a comment

This is Ephemeris for Thursday, May 21st. Today the Sun will be up for 15 hours and 3 minutes, setting at 9:11, and it will rise tomorrow at 6:07. The Moon, 1 day before new, will rise at 6:16 tomorrow morning.

High in the south at 10:30 p.m. or so is a tiny and faint constellation of Coma Berenices, or Berenice’s hair. In it are lots of faint stars arrayed to look like several strands of hair. The whole group will fit in the field of a pair of binoculars, which will also show many more stars. The hank of hair supposed belonged to Berenice II, Queen of Egypt, in the 3rd century BCE. Coma Berenices is the second closest star cluster to us at only 250 light years away, after the Hyades, the face of Taurus the bull a winter constellation. It’s in an odd spot for a galactic star cluster, which are supposed to lie in the plane of the Milky Way. It’s actually seen at the galactic pole, as far as possible away from the milky band. It’s a matter of perspective because it’s so close to us. It’s still really in the plane of the Milky Way.

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

Addendum

Coma Berenices and the galactic pole

Coma Berenices and galactic coordinated showing how close to the galactic pole it is. The bright star Arcturus at the left edge.  Leo’s hind end is at the lower right. Created using Cartes du Ciel (Sky Charts).

Coma Berenices

Approximate 7 power binocular field of view of the Coma Berenices Star Cluster. Created using Cartes du Ciel (Sky Charts).

Note: There is another cluster in the constellation.  It’s called the Coma Cluster.  It’s a cluster of over a thousand galaxies a bit over 300 million light years away.