WR 128

WR 128 is a Wolf–Rayet star located about 9,500 light years away in the constellation of Sagitta. A member of the WN class, WR 128's spectrum resembles that of a WN4 star, but hydrogen is clearly present in the star, making it the only known hydrogen-rich WN4 star in the galaxy. However, similar H-rich very early WN stars can be found in the LMC and especially in the SMC, but the only other galactic examples of this are WR 3 and WR 152.
In 1981, Igor Antokhin et al. discovered that the star, then known as HD 187282, is a variable star. It was given its variable star designation, QT Sagittae, in 1985.

Properties

Analysis of WR 128's spectrum with PoWR shows that it has a temperature of around and is losing mass at a very slow pace, at, or in other words, 1 solar mass every 250,000 years. All this mass is being carried by a very strong stellar wind with a terminal velocity of 2,050 kilometres per second. Taking its distance into account, WR 128 has a luminosity of, or, making it one of the dimmest galactic WN stars. Using the Stefan-Boltzmann Law, we can calculate a radius of. A "transformed" radius at an optical depth of 2/3, more comparable to other types of stars, is at about.