Can stars gain mass ?
Stars can gain mass if they are members of an accreting
binary system. As one star evolves into a red giant, some of its mass can be
captured by a companion star. If that star is a normal star, the added mass
will probably cause the star to burn hotter as its gravitational mass
is increased. If the companion star is a white dwarf or a neutron star, the
matter falls to the surface and builds up until some threshold is reached in
temperature or density, and the surface erupts as a nova explosion. If the
companion is a black hole, the mass is absorbed but some of it is converted
into energy to produce a luminous x-ray source. These are the
more common ways for an evolved star to gain new mass.
Copyright 1997 Dr. Sten Odenwald
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