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1. INTRODUCTION

The last few years have seen a number of discoveries of new satellite companions to the Milky Way. Willman (2005) systematically surveyed ~ 5800 square degrees of the Sloan Digital Sky Survey (SDSS; York et al. 2000) and identified two strong candidates. The first, now called Willman 1, is an unusually extended object with properties intermediate between those of globular clusters and dwarf galaxies (Willman et al. 2005). The second proved to be a new dwarf spheroidal (dSph) companion to the Milky Way, located in the constellation of Ursa Major (Willman et al. 2005, Kleyna et al. 2005).

Very recently, Zucker et al. (2006) serendipitously discovered a stellar overdensity in the "Field of Streams" (Belokurov et al. 2006) - a plot of the halo substructure in the Galactic northern hemisphere derived from SDSS Data Release 5 (DR5; Adelman-McCarthy et al. 2006). Closer analysis revealed that this was a new dwarf spheroidal galaxy, Canes Venatici, at a distance of ~ 200 kpc. All this suggests that there remain unknown Milky Way companions and that further systematic surveys to find them are warranted. Here, we describe a simple algorithm to carry this out in SDSS DR5, and present another strong candidate for a Milky Way satellite, lying in the constellation of Boötes. The properties of this object are somewhat unusual.