Fr.: supergéante bleue
periodically variable supergiant (PVSG)
abarqul-e vartande-ye dowreyi
Fr.: supergéante variable périodiquement
A variable → supergiant star with typical periods of the order of 10 to 100 days and amplitudes less than a few tenths of a magnitude. PVSGs are thought to be pulsating → g modes, caused by a density inversion, arising from an → opacity bump, most likely from Fe, H, and/or He.
abarqul-e sorx (#)
Fr.: supergéante rouge
A supergiant star with spectral type K or M. Red supergiants are the largest stars in the Universe, but not necessarily the most massive. Betelgeuse and Antares are the best known examples of a red supergiant.
supergiant B[e] star (sgB[e])
setâre-ye B[e]-ye abarqul
Fr.: étoile B[e] supergéante
A highly luminous → B[e] star with a luminosity greater than 104L_sun. A number of such objects exist in the → Magellanic Clouds, e.g. LMC R126, R66, SMC R4, and R50. A likely example in our Galaxy is MWC 300.
yellow supergiant (YSG)
abarqul-e zard (#)
Fr.: supergéante jaune
A supergiant star of type F and G whose effective temperature is between 4800 and 7500 K. Yellow supergiants are extremely rare, because they represent a very short-lived phase, typically a few tens of thousands of year, in the evolution of → massive stars.