BD Camelopardalis is an S Class star and also happens to be a symbiotic star. The star is located in the constellation Camelopardalis, which represents the camel-leopard, more commonly known as a giraffe.
Class S stars like BD Camelopardalis have excess zirconium and other s-process elements Most of the carbon and oxygen in them exists as carbon monoxide. Unlike carbon stars and M Class stars, S Class stars have little “leftover” carbon or oxygen to form various other molecules. Most of the stars in this category, like BD Camelopardalis, are giants.
Despite showing zirconium oxide lines, which is characteristic of S Class stars, in its absorption spectrum, BD Camelopardalis shows no technetium lines. On the Hertzsprung-Russell diagram, S Class stars similar to BD Camelopardalis tend to fall in the upper right region (they’re giants!) due to their low temperatures, high radii, and high luminosities.
With an apparent magnitude of 5.115, BD Camelopardalis is often the brightest star of its class in the visible sky. This star has a radius 135 times greater than the Sun’s, and it has an absolute magnitude of -0.9, making it much brighter than the Sun. This star has a parallax of 6.27 milliarcseconds and is approximately 520 light years away.
Class S stars like BD Camelopardalis are similar to classes K5-M in that they are all late-type giant stars. A main distinguishing factor of S Class is that these stars tend to be redder than other stars with the same temperatures.It’s possible that Class S is an intermediate stage for Asymptotic Giant Stars between M Class stars transforming into Class C-N. A hydrogen shell that surrounds an inert core often powers stars like these.
BD Camelopardalis is an example of an “extrinsic” S Class star, meaning that enhancements of carbon are likely products of mass transfer as part of a binary star system. As for the other star in the system, it’s probably a white dwarf that used to be a carbon star. *