IX Carinae

A visual band light curve for IX Carinae, plotted from ASAS data [1]
Observation data Epoch J2000       Equinox J2000
Constellation	Carina
Right ascension	10h 50m 26.300s [2]
Declination	59° 58′ 56.57″ [2]
Apparent magnitude (V)	7.2 - 8.5 [3] or 6.87 - 7.9 [4]
Characteristics
Spectral type	M2Iab [3]
Variable type	SRc [3] [4]
Astrometry
Radial velocity (Rv)	0.90±1.8 [5] km/s
Proper motion (μ)	RA: –6.466 [2]  mas/ yr Dec.: 2.322 [2]  mas/ yr
Parallax (π)	0.4436 ± 0.0220  mas [2]
Distance	7,400 ± 400  ly (2,300 ± 100  pc)
Details
Mass	13 [6]  M☉
Radius	566 [7]  R☉
Luminosity	52,000 [7]  L☉
Temperature	3,660±170 [7]  K
Other designations
IX Car, CD-59°3368, CPD-59°2775, GSC 08626-01670, HD 94096, HIP 52991, IRAS 10484-5943, 2MASS J10502630-5958563, PPM 339497, SAO 238523, TYC 8626-1670-1
Database references
SIMBAD	data

IX Carinae (IX Car) is a red supergiant and pulsating variable star of spectral type M2Iab in the constellation Carina. It is a member of the Carina OB1 association along the Carina Nebula.

IX Carinae is a semiregular variable star, but its properties are poorly-defined. Different sources give its brightness range as magnitude 7.2 to 8.5. ^[3] or 6.87 to 7.9. ^[4] The International Variable Star Index finds a period of approximately 384 days from ASAS-3 and visual observations, but also gives a possible period of 108 days. ^[4] Another analysis finds a primary period of 408±50  d and a longer secondary period of 4,400±2,000 d. ^{[8] [3]}

The physical characteristics of IX Carinae are also only known approximately, partly because of an uncertain distance. The effective temperature is around 3,600  K, ^{[9] [7]} while its bolometric luminosity is between 34,000  L_☉ ^[10] and 134,000 L_☉. ^[9] It is one of the largest stars with a radius of approximately 566  R_☉ (394,000,000  km; 2.63  au). ^[7] If placed at the center of the Solar System, it would extend close to the orbit of the outer Asteroid Belt Jupiter.

IX Carinae has been listed as a candidate supernova close enough to Earth that pre-collapse neutrinos could be detected, allowing for observations of the star to be made from before the supernova explosion. ^[11]

References