RR Lyrae



  • Variable star which has given its name to a group of similar stars, also known as cluster variables because they are often found in galactic clusters. They all have an absolute magnitude of about 0.5 at the peak of their light curve, which means that as soon as one is observed and its apparent magnitude is found, its distance can be found by simple arithmetic. All RR Lyrae stars have periods of variation of under a day.