r hya

Mira Variables with Period Changes

Mira variables are the longest-observed class of stars for which we have long-term quantitative data that allow us to study their behavior over centuries-long periods of time.  Fortunately for us, they're also easy to observe and monitor, having some of the largest amplitudes of all variables, and hundreds of them are bright enough that they're within reach of astronomers with modest telescopes.

R Hydrae

Once, Twice, Three Times a Variable Star!

A page from Hevelius' 1690 Uranographia star atlas, which shows the then unknown variable, R Hya, to be a faint star in the tail of Hydra.