Carbon Stars of Kemble's Cascade

March 04, 2015


: Greg Parker
Summary AuthorGreg Parker

Shown above is Kemble's Cascade, the eye-catching diagonal line of stars in the generally barren constellation of Camelopardalis (the Giraffe). I like to image the reddest stars in the sky, and these are usually carbon stars, having more carbon than oxygen in their outer layers. Carbon stars are always variable stars, and by stellar standards they're cool and thus appear red.

The Kemble's Cascade region boasts two carbon stars, an S-type star, and a beautiful little open cluster (NGC 1502) that looks like a splash pool at the bottom of the starry cascade. Moving to the right from the center of the cascade we find carbon star V Camelopardalis, SAO 12870. This star has a color index (B-V index) of nearly 5. The B-V index gives an indication of the redness of a star -- anything over 2 is very red, so 5 is extremely red. At the bottom of the cascade is carbon star UV Camelopardalis, SAO 13009. UV Camelopardalis has a B-V index of 2.54. Sitting just above V Camelopardalis is another very red star, BD Camelopardalis, SAO 12874. This unusual S-type star exhibits the unique spectral features of zirconium oxide. Also a variable star, BD Camelopardalis can at times be the brightest S-type star in the sky. It has a B-V index of 1.97.

Kemble's Cascade was just recently discovered. It was first noted in 1980, by Father Lucian J. Kemble. He used binoculars while viewing from Alberta, Canada to make his discovery. The above photo was taken from the New Forest Observatory on February 13, 2015.

Photo details: This is a 4-frame mosaic taken with the mini-WASP.