Swan Nebula or horseshoe, is a HII region Nebula ( a region of interstellar hydrogen that is ionized. It is typically a large, low-density cloud of partially ionized gas in whichstar formation has recently taken place) cataloged as Messier M17, located from 5,000 to 6,000 ly away from earth, in the richly field of the Sagittarius region in the Milky way.
The Omega Nebula is a part of an interstellar dust cloud , about 40 ly in diameter and weights 30,000 Solar Mass. However the mass of the Nebula is about 800 solar mass.
The Swan is the most luminous and brightest object with most star formation side in the Milky way , with apparent magnitude of +6 (a number that is a measure of its brightness as seen by an observer on Earth).
An Open cluster NGC 6618 lies embedded in the nebulous causes the gas of the nebula to brights up from the young hot stars. This cluster is one of the youngest star cluster about a 1 million year old. Also in the south east of the M17, a blue hypergiant (HD 168625 caltaloged) is located in the constellation of Sagittarius.
The Nebula is located in Sagittarius, best time of view is August.
astroarabia 