a low mass star that converts helium to carbon is agb star.
a low mass star that converts helium to carbon is agb star.
a low mass star that converts helium to carbon is a?
agb star
white dwarfs are thought to be the final evolutionary state of stars whose mass is not high enough to become a neutron star, that of about 10 solar masses. this includes over 97% of the other stars in the milky way. after the hydrogen-fusing period of a main-sequence star of low or medium mass ends, such a star will expand to a red giant during which it fuses helium to carbon and oxygen in its core by the triple-alpha process. if a red giant has insufficient mass to generate the core temperatures required to fuse carbon (around 1 billion k), an inert mass of carbon and oxygen will build up at its center. after such a star sheds its outer layers and forms a planetary nebula, it will leave behind a core, which is the remnant white dwarf. usually, white dwarfs are composed of carbon and oxygen. if the mass of the progenitor is between 8 and 10.5 solar masses (), the core temperature will be sufficient to fuse carbon but not neon, in which case an oxygen–neon–magnesium white dwarf may form. stars of very low mass will not be able to fuse helium, hence, a helium white dwarf may form by mass loss in binary systems.
white dwarf
the infrared source irs1 is close to σ ori a. it has been resolved to a pair of low mass objects, a proplyd, and a possible third object. the brighter object has an m1 spectral class, a mass around , and appears to be a relatively normal low mass star. the fainter object is very unusual, showing a diluted m7 or m8 absorption spectrum with emission lines of hydrogen and helium. the interpretation is that it is a brown dwarf embedded within a proplyd that is being photoevaporated by σ ori a. x-ray emission from irs1 suggests the presence of an accretion disc around a t tauri star, but it is unclear how this can fit with the proplyd scenario.
sigma orionis