Paper: astro-ph/0506460
Date: Mon, 20 Jun 2005 15:57:40 GMT (79kb)

Title: Two New Milky Way Companions

Authors: Beth Willman
Comments: 10 pages. Proceedings of "Resolved Stellar Populations". Held in
Cancun, Mexico, 18-22 Apr 2005, ASP Conference Series eds D. Valls-Gabaud &
M. Chavez
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We discuss the detection limits and current status of a uniform survey of
SDSS I for ultra-faint Milky Way dwarf galaxies. We present the properties of
two new, low surface brightness Milky Way companions discovered as a result of
this survey. One of these companions is the Ursa Major dwarf, the newest dwarf
spheroidal companion to the Milky Way and the lowest luminosity galaxy yet
known. Ursa Major is about 100 kpc away and is similar to Sextans, but with
roughly an order of magnitude fewer stars. The other companion, SDSSJ1049+5103,
lies $\sim$ 50 kpc away. Its stellar distribution suggests that it may be
undergoing tidal stripping. This companion is extremely faint (M$_V$ $\sim$ -3)
but has a large half-light size for its luminosity. It is therefore unclear
whether it is a globular cluster or a dwarf galaxy.

http://arXiv.org/abs/astro-ph/0506460