SUPERMASSIVE DARK STARS: DETECTABLE IN JWST

The first phase of stellar evolution in the history of the universe may be dark stars (DSs), powered by dark matter (DM) heating rather than by nuclear fusion. Weakly interacting massive particles (WIMPs), which may be their own antipartners, collect inside the first stars and annihilate to produce a heat source that can power the stars for millions to billions of years. In this paper, we show that these objects can grow to be supermassive dark stars (SMDSs) with masses greater than or similar to(10(5)-10(7)) M-circle dot. The growth continues as long as DM heating persists, since DSs are large and cool (surface temperature less than or similar to 5 x 10(4) K) and do not emit enough ionizing photons to prevent further accretion of baryons onto the star. The DM may be provided by two mechanisms: (1) gravitational attraction of DM particles on a variety of orbits not previously considered and (2) capture of WIMPs due to elastic scattering. Once the DM fuel is exhausted, the SMDS becomes a heavy main-sequence star; these stars eventually collapse to form massive black holes (BHs) that may provide seeds for supermassive BHs in the universe. SMDSs are very bright, with luminosities exceeding (10(9)-10(11)) L-circle dot. We demonstrate that for several reasonable parameters, these objects will be detectable with the James Webb Space Telescope. Such an observational discovery would confirm the existence of a new phase of stellar evolution powered by DM.