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 />
A spectrograph shows that each of the two bright components, A and B, is itself a double. Castor A consists of almost identical stars, each of about 2 solar masses, orbiting each other every 9.22 days and about one-tenth the distance of Mercury from the Sun. Castor B's twin stars orbit even faster, making their circuit in a mere 2.9 days. The faint, distant star, Castor C, is also double, consisting of nearly identical, low-mass M stars â red dwarfs â with temperatures of about 4,000K, some two solar diameters apart with an orbital period of 20 hours. One or both are flare stars.