Stellar Structure of Dark Stars: a first phase of Stellar Evolution due to Dark Matter Annihilation

Dark Stars are the very first phase of stellar evolution in the history of the universe: the first stars to form (at redshifts z ∼ 10 − 50) are powered by dark matter annihilation instead of fusion (if the dark matter is made of particles which are their own antipartners). We find equilibrium polytropic configurations for these stars; we start from the time DM heating becomes important (M ∼ 1 − 10M⊙) and build up the star via accretion up to 1000M⊙. The dark stars, with an assumed particle mass of 100 GeV, are found to be very bright with a luminosity of a few 106L⊙, surface temperatures (4000− 10,000)K, radii ∼ 10cm, and lifetimes of at least 10 years. Dark stars look quite different from standard metal free stars in the absence of DM heating and can be distinguished in future observations, possibly even in JWST or TMT. In addition, dark stars are predicted to have atomic and molecular hydrogen lines.