I’m a former developer, occasional boat-builder, full-time caregiver for a disabled adult. I’ve always been interested in astronomy and modern physics but just recently decided to get serious about it! I’ve been learning everything I can about astronomy and astrophysics and I’m truly having a blast with every aspect. Right now I’m working through some of the core physics and astro curriculum through MIT Open Course Ware.
R Lyrae is a M5 III class red giant star on the Asymptotic Giant Branch (AGB). It is 4th magnitude visually, but is very bright in the infrared. In J-band near infrared it is brighter than Vega, and is one of the 14 brightest star in the sky in the K-band. As an AGB star its structure consists of a inert central core of carbon and oxygen, surrounded by a helium burning shell, itself surrounded by a hydrogen burning shell. And around it all is a very large stellar atmosphere - perhaps in the range of 1 AU radius. The chromosphere is observed to be complex and turbulent, with gas moving in or outward by up to 10 km/s. The star is estimated to have had an initial mass of 2 solar masses, and is currently around 1.8 solar masses. The remaining mass has been blown into interstellar space by a powerful stellar wind.