WR 119 is a Wolf–Rayet star located about 10,500 light years away in the constellation Scutum. WR 119 is classified as a WC9 star, belonging to the late-type carbon sequence of Wolf-Rayet stars. WR 119 is noteworthy for being the least luminous known Wolf-Rayet star, at just over 50,000 L_☉.[3] The most recent estimate is even lower, at just 42,700 L_☉, based on the most recent analysis using Gaia DR2 data.[4]

Properties

WR 119's properties are on the very edge of what may be possible for Wolf-Rayet stars, due to being so extremely dim. Modelling its spectrum using PoWR gives a temperature of 45,000 K. Factoring in the distance used in that study of 3,500 pc, WR 119's luminosity is only 50,100 L_☉, derived from Gaia DR2's parallax data. The corresponding radius is only 3.7 R_☉, the smallest of the WC9 stars, less than half the size of the average WC9 star. WR 119's luminosity is also just 20% that of the average WC9 star's luminosity. The corresponding mass is just 5.8 M_☉, the lowest mass for any Wolf-Rayet star derived using a mass-luminosity relation.[3]

In the visual wavelength, the star is also the dimmest of the WC9 stars (and anything later than WC4 in the study), with a visual luminosity of just 3,130 L☉[3] because most of the 50,100 L_☉ is emitted at ultraviolet wavelengths due to WR 119's very high surface temperature.

WR 119 has a strong stellar wind, typical of Wolf-Rayet stars, but weaker than most WC stars. WR 119 loses 10^-5.13 M☉ (about 7.41×10⁻⁶ M_☉) per year because of this stellar wind, which has a terminal velocity of 1,300 kilometres per second. WR 119 also emits a lot of dust, hence the "d" at the end of its spectral type,[3] which may be an indication of binary status.

References