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 />
Castor A and B are both comprised of almost identical A-type main sequence stars with orbital periods of 9.2 days and 2.9 days, respectively. C is also a binary twin set, this time made up of low-mass red dwarfs locked in a 19.5-hour orbit. What the unaided eye sees as a single star is actually a triplet of twins! Besides its value as a âwowâ object, thereâs another good reason for adding Castor to your star party repertoire. Bright double stars arenât as adversely affected by haze or light-polluted skies as are deep-sky objects like nebulae and galaxies.