by Bill Pellerin, GuideStar editor
Update: The AAVSO has posted a notice on its web site that the eclipse will not happen at the anticipated date and time.
Object: Diadem—Alpha Com
Class: Double Star
R.A.: 13 h, 9 m, 59 s
Dec: 17 degrees, 31 minutes, 48 seconds
Distance: 47 ly
Constellation: Coma Berenices
Optics needed: Unaided Eye
Why this object is interesting
The name of this star means crown or other ornament representing royalty. In this case the crown is in the constellation Coma Berenices (Berenice’s hair) and this star represents the crown on the head of queen Berenice.
All well and good, but the thing that makes this star interesting to observers is that it is a binary star consisting of two mag 5 stars very near each other and with an orbital period of about 26 years. Remember that orbiting objects orbit around the center of mass of the system, so, in this case it’s more like a dance in the sky than it’s like a low mass object orbiting a high mass object.