Asterisms – Brosch 1, Virgo Diamond

Original article appears in GuideStar April, 2021.

By: Steve Goldberg

Asterism: a grouping of stars that form a recognizable pattern.
Constellation: Virgo                       
Right Ascension:  12h 33m 19.0s
Declination:  -00° 38' 42" Magnitude:  11 to 13
Size: 42”

This asterism is located in Virgo. Starting with Spica, locate star Porrima Gamma γ VIRGO. This star is the “anchor point” for the semi-circle of stars in Virgo.

Just above a line from Porrima to Zaniah Eta η VIRGO, Brosch 1 can be located.

Brosch 1 is a square or diamond, depending on how it appears in your eyepiece. The object first appears as 4 stars. But looking closer, one of the stars is a double. See if you can split that double. Another name for this asterism is the Virgo Diamond, which is very descriptive.

Brosch 1 is named for Noah Brosch, an Israeli astronomer still doing research today. Here is Wiki info on Brosch.

Wiki Noah Brosch






HAS Online Store

Get Connected!

HAS has begun using RainedOut, a text message service, to communicate late-breaking news about events. Click here to learn more and subscribe!

Night Sky Network