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.
In 1948, Daniel Joseph Kelly O'Connell announced that the star is a variable star. 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. or 6.87 to 7.9. 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. Another analysis finds a primary period of and a longer secondary period of .
The physical characteristics of IX Carinae are also only known approximately, partly because of an uncertain distance. The effective temperature is around , while its bolometric luminosity is between and . It is one of the largest stars with a radius of approximately . If placed at the center of the Solar System, it would extend close to the orbit of the outer asteroid belt.
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.
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