Mira, Omicron Ceti (ο Cet), is an evolved red giant star located in the constellation Cetus. It is a pulsating variable that serves as a prototype for its own class of stars, known as the Mira variables. . . . The white dwarf companion, Mira B, has the stellar classification DA, indicating a hydrogen-rich atmosphere. In 1995, Mira B was resolved by the Hubble Space Telescope. The ultraviolet images obtained with the HST and the subsequent Chandra observations showed a bridge of gas flowing from Mira to the companion.
https://www.star-facts.com/mira/
Mira has an average peak brightness of magnitude 3.5. It’s not one of the sky’s brightest stars, even when brightest. It gradually fades to around magnitude 9 (too faint to see with the eye; for reference, in a dark sky, the unaided eye can barely detect a magnitude 6 star). Then it rebounds back to its peak brightness. So Mira undergoes about a 159-fold change in brightness, as it moves through its 332-day brightness cycle.
Mira’s 13-light-year-long tail
In 2006, the Galaxy Evolution Explorer telescope obtained ultraviolet images of Mira that surprised scientists. They revealed a long comet-like tail of material trailing the star as it sped through ambient galactic gas. Mira moves through this space at about 290,000 miles per hour (130 km/s). The tail, about 13 light-years long, is composed of gases and dust released by Mira over the last 30,000 years. The amount of gases and dust in Mira’s tail equal about 3,000 times the Earth’s mass.
@Oneofthestormboys I was familiar with Cepheid variables, because they are a kind of "standard candle" for establishing absolute magnitudes and thus cosmic distances. Cepheids are named after Delta Cephei, in the constellation Cepheus. So it was kinda confusing to encounter a different kind of variable in Cetus. Ceteid would be a bad name for the class; hence Mira type variable. Anyway, it was a great rabbit hole to go down!
