It is believed this is the origin of the extreme helium stars.
2.
? Sgr 1 is a helium star, almost entirely deficient of hydrogen.
3.
Later this will become an extreme helium star before cooling to become a white dwarf.
4.
These include cool helium stars, and dense planetary nebulae ( in particular NGC 7027 ).
5.
The luminosity is estimated from helium star models to be and the star has a radius around.
6.
The known extreme helium stars are supergiants where hydrogen is underabundant by a factor of 10, 000 or more.
7.
It has been proposed that it is a degenerate star or a hot helium star, but it seems unlikely that it is a normal star.
8.
PV Telescopii is a class B-type ( blue ) extreme helium star that is the prototype of a class of variables known as PV Telescopii variables.
9.
"' V803 Centauri "'( V803 Cen ) is a cataclysmic binary consisting of a dwarf helium star losing mass to a white dwarf.
10.
It is possible that the diversity of R CrB stars is caused by a diversity of formation mechanisms, relating them to extreme helium stars and hydrogen-deficient carbon stars.
मोबाइल