RX Boötis

RX Boötis is a variable star located in the constellation Boötes. It is classified as a Mira variable, a type of pulsating red giant star. These stars are characterized by their long periods of variability, typically ranging from 80 to 1,000 days, and large changes in brightness.

RX Boötis has a period of approximately 224 days. During this period, its visual magnitude varies significantly, fluctuating between a maximum brightness of around magnitude 9 and a minimum brightness of around magnitude 14. This large amplitude in brightness is a characteristic feature of Mira variables.

The star is relatively cool, with a surface temperature of around 3,000 Kelvin. As a red giant, RX Boötis has expanded considerably from its original size, now possessing a large radius and relatively low density. The pulsations are caused by instabilities in the star's outer layers, leading to expansion and contraction. These pulsations result in changes in temperature and radius, which ultimately cause the observed variations in brightness.

Observations of RX Boötis, like other Mira variables, are valuable for understanding stellar evolution and the processes that occur in the late stages of a star's life. Its significant variability makes it an accessible target for amateur astronomers equipped with telescopes and suitable observing techniques. Light curves, which plot the star's brightness over time, can be constructed from observations, providing valuable data for analysis.