About 29 CMa
29 CMa is an epic variable star. It lies about 1,907.3 light-years from Earth, sits in the constellation CMa, shines at apparent magnitude 4.88 and has spectral type O7f.
Its spectrum reads O7f — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.