Other causes of valve disease include: 1  Deposits of calcium (calcification) in parts of the valve. 2  A floppy valve, which is a common cause of mild mitral valve regurgitation. 3  Some congenital heart problems. 4  Infection of the valve (infective endocarditis). 5  A complication of various uncommon diseases.
exists and is an alternate of . Castor is a variable star and also a quadruple star system, and has a spectral class of A1/A2 giving it a colour of white to white blue. Castor is a variable star and also a quadruple star system, and has a spectral class of A1/A2 giving it a colour of white to white blue. See link for more information.  <br /><br /> See link for more information. Castor is a variable star and also a quadruple star system, and has a spectral class of A1/A2 giving it a colour of white to white blue. <br /><br />
Introduction: Welcome to the Astronomical Leagueâs Carbon Star Observing Program! Carbon stars are a unique and interesting type of variable star that exhibits peculiar characteristics and spectra.Most are red giant stars, and their distinguishing feature (and namesake) is the unusually high level of carbon molecules contained in their atmospheres.elcome to the Astronomical Leagueâs Carbon Star Observing Program! Carbon stars are a unique and interesting type of variable star that exhibits peculiar characteristics and spectra.