  If the supermassive black hole (SMBH) at the center of our Galaxy grew
adiabatically, then a dense "spike" of dark matter is expected to have formed
around it. Assuming that dark matter is composed primarily of weakly
interacting massive particles (WIMPs), a star orbiting close enough to the SMBH
can capture WIMPs at an extremely high rate. The stellar luminosity due to
annihilation of captured WIMPs in the stellar core may be comparable to or even
exceed the luminosity of the star due to thermonuclear burning. The model thus
predicts the existence of unusual stars, i.e. "WIMP burners", in the vicinity
of an adiabatically grown SMBH. We find that the most efficient WIMP burners
are stars with degenerate electron cores, e.g. white dwarfs (WD) or degenerate
cores with envelopes. If found, such stars would provide evidence for the
existence of particle dark matter and could possibly be used to establish its
density profile. In our previous paper we computed the luminosity from WIMP
burning for a range of dark matter spike density profiles, degenerate core
masses, and distances from the SMBH. Here we compare our results with the
observed stars closest to the Galactic center and find that they could be
consistent with WIMP burners in the form of degenerate cores with envelopes. We
also cross-check the WIMP burner hypothesis with the EGRET observed flux of
gamma-rays from the Galactic center, which imposes a constraint on the dark
matter spike density profile and annihilation cross-section. We find that the
EGRET data is consistent with the WIMP burner hypothesis. New high precision
measurements by GLAST will confirm or set stringent limits on a dark matter
spike at the Galactic center, which will in turn support or set stringent
limits on the existence of WIMP burners at the Galactic center.
