In this Letter , we announce the discovery of a new satellite of the Milky Way in the constellation of Boötes at a distance of \sim 60 kpc .
It was found in a systematic search for stellar overdensities in the North Galactic Cap using Sloan Digital Sky Survey Data Release 5 ( SDSS DR5 ) .
The color-magnitude diagram shows a well-defined turn-off , red giant branch , and extended horizontal branch .
Its absolute magnitude is M _ { V } \sim - 5 \fm 8 , which makes it one of the faintest galaxies known .
The half-light radius is \sim 220 pc .
The isodensity contours are elongated and have an irregular shape , suggesting that Boo may be a disrupted dwarf spheroidal galaxy .