Big fish, little fish: Two new ultra-faint satellites of the milky way

V. Belokurov, M. G. Walker, N. W. Evans, G. Gilmore, M. J. Irwin, D. Just, S. Koposov, M. Mateo, E. Olszewski, L. Watkins, L. Wyrzykowski

Research output: Contribution to journalArticlepeer-review

158 Scopus citations


We report the discovery of two new Milky Way satellites in the neighboring constellations of Pisces and Pegasus identified in data from the Sloan Digital Sky Survey. Pisces II, an ultra-faint dwarf galaxy lies at the distance of 180 kpc, some 15°away from the recently detected Pisces I. Segue 3, an ultra-faint star cluster lies at the distance of 16 kpc. We use deep follow-up imaging obtained with the 4-m Mayall Telescope at Kitt Peak National Observatory to derive their structural parameters. Pisces II has a half-light radius of 60 pc, while Segue 3 is 20 times smaller at only 3 pc.

Original languageEnglish (US)
Pages (from-to)L103-L106
JournalAstrophysical Journal Letters
Issue number1 PART 2
StatePublished - 2010


  • Galaxies: dwarf
  • Galaxies: individual (Pisces, Pegasus)
  • Local Group

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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