Tags: Star.
HD 179821 is a massive bright star in the constellation of Aquila generally classified as a G-type yellow hypergiant of perhaps 30 solar masses at a distance from Earth of roughly 6000 parsecs (20000 light-years). It is surrounded by a dust shell that contributes to a double-peaked spectral energy distribution. It is estimated the star has lost about 10% of its initial mass after being a red supergiant star just 1600 years ago and is a likely supernova candidate.
