Asterism in Aquarius

 

Messier 73 , M 73
 

 

Image Information
Date Imaged

?/2006

Location Imaged From

Tierra del Sol , CA

Equipment Telescope: Meade 10" LX200
Mount: Ulti-Wedge
Camera: SBIG ST-7e CCD NABG
Focal Ratio: f/6.3
Exposure Information

Lum: 5 X 2 min binned 1 X 1
RGB: 5 X 1 min binned 1 X 1

Messier 73 (also known as M73 and NGC 6994) is an asterism of four stars in the constellation of Aquarius. An asterism is comprised of physically unconnected stars that appear close to each other in the sky as seen from Earth. M73 is one of the best-known asterisms in the sky, and it has been carefully studied scientifically.

M73 was discovered by Charles Messier on October 4, 1780, who originally described the object as a cluster of four stars with some nebulosity. Subsequent observations by John Herschel, however, failed to reveal any nebulosity. Moreover, Herschel noted that the designation of M73 as a cluster was questionable. Nonetheless, Herschel included M73 in the General Catalogue of clusters, nebulae, and galaxies, and John Dreyer included M73 when he compiled the New General Catalogue.