Surveillance performed during use of the MegaPrime/MegaCam 1 deg2 ( camera ) on the Canada-France-Hawaii Telescope ( CFHT ) had mapped M31 stellar halo ( one quarter ) up to ~ 150 kpc .
The MegaPrime/MegaCam 1 deg2 ( camera ) on the Canada-France-Hawaii Telescope ( CFHT ) had mapped the M31 stellar halo ( one quarter ) up to ~ 150 kpc .