Eta Sagittarii [SEP] constellation
Eta Sagittarii
Eta Sagittarii (Eta Sgr, η Sagittarii, η Sgr) is a binary star system in the southern zodiac constellation of Sagittarius. Based upon parallax measurements, it is located at a distance of from Earth. It was formerly known as Beta Telescopii (β Tel). In India, where part of the constellation of Sagittarius represents an Elephant, this star forms the creature's tail.
The primary component, η Sagittarii A, is a red giant star with a stellar classification of
classification E4 and the other a lenticular galaxy of classification S0. IC 4808 is a galaxy of apparent magnitude 12.9 located on the border of Corona Australis with the neighbouring constellation of Telescopium and 3.9 degrees west-southwest of Beta Sagittarii. However, amateur telescopes will only show a suggestion of its spiral structure. It is 1.9 arcminutes by 0.8 arcminutes. The central area of the galaxy does appear brighter in an amateur instrument, which shows it to be tilted northeast-southwest.
Southeast of Theta and southwest of Eta lies the