S Carinae is an M-typered giant with a mean apparent magnitude of +6.94. It is approximately 1,620 light years from Earth. It is classified as a Mira typevariable star and its brightness varies between magnitude +4.5 and +10.0 with a period of 149.49 days.[3] It has one of the earliest spectral types, and hence the hottest temperatures, of any Mira variable, and has a relatively short period for the class.[10] The temperature of this pulsing star is highest at visual brightness maximum and lowest at visual brightness minimum.[9]
S Carinae has exhausted its core hydrogen and expanded to become a red giant. It has also exhausted its core helium and evolved to the asymptotic giant branch, where it fuses hydrogen and helium in separate shells outside the core.[10][4]
^ abcdSamus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
^ abcEggen, O. J. (1972). "Narrow-and broad-band photometry of red stars. VII. Luminosities and temperatures for halo-population red stars of high luminosity". The Astrophysical Journal. 172: 639. Bibcode:1972ApJ...172..639E. doi:10.1086/151383.
^Celis, L. (1995). "Luminosity Attenuation and Distances of Red Giant Stars". The Astrophysical Journal Supplement Series. 98: 701. Bibcode:1995ApJS...98..701C. doi:10.1086/192175.
