Top Qs
Timeline
Chat
Perspective
R Octantis
Variable star in the constellation Octans From Wikipedia, the free encyclopedia
Remove ads
R Octantis, also known as HD 40857, is a solitary, red hued variable star located in the southern circumpolar constellation Octans. It has an apparent magnitude that varies in-between 6.4 and 13.2 within 405 days.[3] At is maximum, it is barely visible to the naked eye. The object is located relatively far at a distance of about 1,900 light years based on parallax measurements from Gaia DR3,[2] but is receding with a heliocentric radial velocity of 46 km/s.[6]
Remove ads
R Octantis has been known to have a peculiar spectra since 1892.[10] It was revealed to have emission lines in its spectrum in a 1954 paper[11] and was found to be a long period variable a year later.[12] In 1966, R Octantis was officially classified as a Mira variable.[4] Later observations reveal it to have an overabundance of oxygen on its outer layers.[13]
The object has an average stellar classification of M5.5e, indicating that it is a M-type star with emission lines in its spectrum.[4] However, this can range from M5.3 to M8.4e.[3] It is currently on the asymptotic giant branch, generating energy by fusing hydrogen and helium shells around an inert carbon core. As a result, it has expanded to 466 times the radius of the Sun.[7] R Octantis radiates over 9,000 times the luminosity of the Sun from its photosphere at an effective temperature of 2,571 K,[8] which is cooler than most Mira variables.
Remove ads
References
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads