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 />
Cepheid variable stars are the name for a special type of variable star first discovered in the constellation Cepheus. Cepheids are extremely important to astronomers because their periodic changes in brightness can be used to figure out how far away they are.epheid variable stars are the name for a special type of variable star first discovered in the constellation Cepheus. Cepheids are extremely important to astronomers because their periodic changes in brightness can be used to figure out how far away they are.