V538 Carinae is a variable star in the constellation of Carina, and a possible red supergiant. If this star replaced the Sun in the Solar System, its photosphere would at least engulf the orbit of Mars.
Properties
V538 Carinae has a measured angular diameter of . Its distance is uncertain. At the Hipparcos distance of , this corresponds to a radius of , but at the distance implied by its Gaia Data Release 2 parallax, the radius would be around . Calculations based on the Gaia DR2 parallax with temperatures and bolometric corrections inferred from Gaia colours give an even larger radius above .
Some studies suggest that this star is a luminous AGB star and a long-period variable, instead of a supergiant. It is classified in the General Catalogue of Variable Stars as a semiregular variable star of type SRb, indicating a cool pulsating giant star, with a possible period of 655 days. Its brightness varies between extremes of magnitude 7.7 and 9.2.
Notes
References
Semiregular variable stars
Carinae, V538
M-type supergiants
M-type bright giants
098658
Carina (constellation) 055355 TIC objects
