| Authors | Zucker, Daniel B.; Kniazev, Alexei Y.; MartÃnez-Delgado, David; Bell, Eric F.; Rix, Hans-Walter; Grebel, Eva K.; Holtzman, Jon A.; Walterbos, Rene A. M.; Rockosi, Constance M.; York, Donald G.; Barentine, J. C.; Brewington, Howard; Brinkmann, J.; Harvanek, Michael; Kleinman, S. J.; Krzesinski, Jurek; Long, Dan; Neilsen, Eric H., Jr.; Nitta, Atsuko; Snedden, Stephanie A. |
| Abstract | We report the discovery of Andromeda X, a new dwarf spheroidal satellite of M31, based on stellar photometry from the Sloan Digital Sky Survey. Using follow-up imaging data we have estimated its distance and other physical properties. We find that Andromeda X has a dereddened central surface brightness of μV,0~26.7 mag arcsec-2 and a total apparent magnitude of Vtot~16.1, which at the derived distance modulus, (m-M)0~24.12-24.34, yields an absolute magnitude of MV~-8.1+/-0.5 these values are quite comparable to those of Andromeda IX, a previously discovered low-luminosity M31 satellite. The discoveries of Andromeda X and of numerous other extremely faint satellites around M31 and the Milky Way in the past few years suggest that such objects may be plentiful in the Local Group. |
