WR 102ea

WR 102ea is a Wolf–Rayet star in the Sagittarius constellation. It is the third most luminous star in the Quintuplet cluster after WR 102hb. With a luminosity of 2,500,000 times solar, it is also one of the most luminous stars known. Despite the high luminosity it can only be observed at infra-red wavelengths due to the dimming effect of intervening dust on visual light.

WR 102ea

WR 102ea (circled) in the Quintuplet Cluster
Observation data Epoch J2000      Equinox J2000
Constellation	Sagittarius
Right ascension	17h 46m 15.12s[1]
Declination	−28° 49′ 36.9″[1]
Characteristics
Evolutionary stage	Wolf Rayet
Spectral type	WN9h[2]
Apparent magnitude (K)	8.8[3]
Astrometry
Radial velocity (Rv)	116[4] km/s
Proper motion (μ)	RA: -0.59[1] mas/yr Dec.: -1.21[1] mas/yr
Distance	26k[2] ly (8k[2] pc)
Details
Mass	58[5] M☉
Radius	86[2] R☉
Luminosity	2.5 million[2] L☉
Temperature	25,100[2] K
Age	~4[5] Myr
Other designations
FMM 241, qF 241, (erroneously QPM-241), Q10, MGM 5-10, LHO 71
Database references
SIMBAD	data

It is an evolved massive star which has an emission line spectrum from a strong stellar wind caused by high luminosity and the presence of elements heavier than hydrogen in the photosphere. The spectrum is dominated by ionised helium and nitrogen lines due to convectional and rotational mixing of fusion products to the surface of the star. However it is still in a core hydrogen burning phase and hydrogen lines are also visible in the spectrum, in contrast to WN stars without hydrogen which are older, less massive, and less luminous. Despite being a relatively unevolved star, WR 102ea has lost over half its mass already.^[5]