Hydrogen-deficient star the outer layer of the star. The double degenerate scenario is a binary-star approach in which a smaller degenerate helium white dwarf and a larger carbon-oxygen white dwarf orbit each other so closely that they eventually inspiral due to gravitational wave losses. At the Roche limit, mass transfer takes place from the helium to the carbon-oxygen star. The latter undergoes helium shell burning to form a supergiant and evolve to a hydrogen-deficient star. The double degenerate scenario provides a better fit to the observational data. Hydrogen-deficient star A hydrogen-deficient star is a type of star that has little or no
Omega Carinae Omega Carinae is a shell star, having a circumstellar disk of gas surrounding its equator. The luminosity class of III indicates it has evolved into a giant star, having exhausted the hydrogen at its core and left the main sequence. The effective temperature of 13,275 K in its outer envelope is what gives this star the blue-white hue that is characteristic of B-type stars. This star is rotating rapidly with a projected rotational velocity of , which gives a lower limit to the star's azimuthal velocity along the equator. The critical equatorial velocity, at which the star would begin to