Astronomy:Triangulum II
Coordinates: 
02h 13m 17.4s, +36° 10′ 42.4″
| Triangulum II | |
|---|---|
| Observation data (J2000 epoch) | |
| Constellation | Triangulum |
| Right ascension | 02h 13m 17.4s[1] |
| Declination | +36° 10′ 42.4″[1] |
| Distance | 97.8 ± 6.5 kly (30 ± 2 kpc)[1] |
| Characteristics | |
| Mass/Light ratio | 3600 (V)[1] M☉/L☉ |
| Apparent size (V) | 3.9′[1] |
| Other designations | |
| Triangulum II, Tri II, Laevens 2, Lae 2 | |
Triangulum II (Tri II or Laevens 2) is a dwarf galaxy close to the Milky Way Galaxy. Like other dwarf spheroidal galaxies, its stellar population is very old: the galaxy was quenched before 11.5 billion years ago.[2] It contains only 1000 stars, yet is quite massive, having a solar mass to light ratio of 3600.[3] This is an unusually high mass for such a small galaxy.[4]
The distance from the centre of the Milky Way is 26 kpc (85 kly). The luminosity is 450 times that of the Sun.[3] This makes it one of the dimmest known galaxies.[3] The 2D half light radius is 34 pc (110 ly). The galaxy was discovered in images taken by Pan-STARRS by Benjamin P. M. Laevens in 2015.[1][3]
Triangulum II is a candidate for detecting WIMPs as a source of dark matter.[4]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Laevens, Benjamin P. M.; Martin, Nicolas F.; Ibata, Rodrigo A.; Rix, Hans-Walter; Bernard, Edouard J.; Bell, Eric F.; Sesar, Branimir; Ferguson, Annette M. N. et al. (31 March 2015). "A New Faint Milky Way Satellite Discovered in the PAN-STARRS1 3π Survey". The Astrophysical Journal 802 (2): L18. doi:10.1088/2041-8205/802/2/L18. Bibcode: 2015ApJ...802L..18L. http://dro.dur.ac.uk/16298/1/16298.pdf?DDD25+dph1nm+d700tmt.
- ↑ Sacchi, Elena; Richstein, Hannah; Kallivayalil, Nitya; Van Der Marel, Roeland; Libralato, Mattia; Zivick, Paul; Besla, Gurtina; Brown, Thomas M. et al. (2021). "Star Formation Histories of Ultra-faint Dwarf Galaxies: Environmental Differences between Magellanic and Non-Magellanic Satellites?". The Astrophysical Journal Letters 920 (1): L19. doi:10.3847/2041-8213/ac2aa3. Bibcode: 2021ApJ...920L..19S.
- ↑ 3.0 3.1 3.2 3.3 "Triangulum II: Possibly a Very Dense Ultra-Faint Dwarf Galaxy". The Astrophysical Journal 814 (1): L7. 16 November 2015. doi:10.1088/2041-8205/814/1/L7. Bibcode: 2015ApJ...814L...7K.
- ↑ 4.0 4.1 Dajose, Lori (18 November 2015). "Dark matter dominates in nearby dwarf galaxy". Phys.org. http://phys.org/news/2015-11-dark-dominates-nearby-dwarf-galaxy.html. Retrieved 19 November 2015.; Lori Dajose (November 18, 2015). "Dark Matter Dominates in Nearby Dwarf Galaxy". Caltech. http://www.caltech.edu/news/dark-matter-dominates-nearby-dwarf-galaxy-48790.
| Location | Milky Way → Milky Way subgroup → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → Observable universe → Universe Each arrow (→) may be read as "within" or "part of". |  | |||||||
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