Abstract
We present the discovery of a faint Milky Way satellite, Laevens 2/Triangulum II, found in the Panoramic Survey Telescope And Rapid Response System 3π imaging data and confirmed with follow-up wide-field photometry from the Large Binocular Cameras. The stellar system, with an absolute magnitude of MV = -1.8 ± 0.5, a heliocentric distance of 30-2+2 kpc, and a half-mass - radius of 34-8+9 pc, shows remarkable similarity to faint, nearby, small satellites such as Willman 1, Segue 1, Segue 2, and Boötes II. The discovery of Laevens 2/Triangulum II further populates the region of parameter space for which the boundary between dwarf galaxies and globular clusters becomes tenuous. Follow-up spectroscopy will ultimately determine the nature of this new satellite, whose spatial location hints at a possible connection with the complex Triangulum - Andromeda stellar structures.
Original language | English (US) |
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Article number | L18 |
Journal | Astrophysical Journal Letters |
Volume | 802 |
Issue number | 2 |
DOIs | |
State | Published - Apr 1 2015 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- Galaxies: dwarf
- Galaxy: structure
- Globular clusters: general
- Local group