RR Herculis (RR Her) is the small red star in the middle of the image.
RR Her is a variable star with an unusual spectral type of SC5.5-C71e. The S designation means it falls somewhere between a class M star and a carbon star. Visually, it is observed to be the classic deep-hued red color common to most other carbon stars.
RR Herculis is a pulsating variable that ranges in visual magnitude from 8.80 to 13.5 over a period of 238.7 days. It too faint to be seen by the naked eye and a telescope is required to view this star.
The star is 1209.6286 parsecs from us which means it is roughly 3945.2808253 light years away.
RR Herculis was one of four long period carbon stars studied in the 1977 paper submitted to the Astrophysical Journal titled Enhanced carbon abundances in long-period variable carbon stars. (Thompson R.I.). The study indicates that the enhanced carbon levels in such stars are in part due to helium shell flash events that the stars perodically undergo. When the flash occurs, complex processs occur within the star that cause the transport of additional carbon to the outer layers where it forms an observable abundance.
