Crater 2 Dwarf
Coordinates: 
11h 49m 14.4s, −18° 24′ 46.8″
| Crater 2 | |
|---|---|
| Observation data (J2000.0 epoch) | |
| Constellation | Crater[1] |
| Right ascension | 11h 49m 14.400s 177.310°±0.03°[1] |
| Declination | −18° 24′ 46.80″ −18.413°±0.03°[1] |
| Distance | 383,000 ly (117.5 kpc)[1] |
| Apparent magnitude (V) | 20.35±0.02 mag[1] |
| Absolute magnitude (V) | −8.2±0.1 mag[1] |
| Characteristics | |
| Type | dSph[1] |
| Apparent size (V) | 62.4′ (rh=31.2′ ± 2.5′)[1] 6,950 ly (2,132 pc) rh=1066pc ± 84pc[1] |
| Notable features | 4th largest satellite galaxy to Milky Way[1] |
Crater 2 is a low-surface-brightness dwarf satellite galaxy of the Milky Way,[1] located approximately 380,000 ly from Earth. Its discovery in 2016 revealed significant gaps in astronomer's understanding of galaxies possessing relatively small half-light diameters and suggested the possibility of many undiscovered dwarf galaxies orbiting the Milky Way. [2] Crater 2 was identified in imaging data from the VST ATLAS survey.[2]
The galaxy has a half-light radius of ∼1100 pc, making it the fourth largest satellite of the Milky Way.[1] It has an angular size about double of that of the moon.[2][3] Despite the large size, Crater 2 has a surprisingly low surface brightness, implying that it is not very massive.[4] This may be a result of tidal interactions with it and larger galaxies, such as the Milky Way and the Large Magellanic Cloud.[4]
See also[edit]
References[edit]
- ^ a b c d e f g h i j k l Torrealba, G.; Koposov, S. E.; Belokurov, V.; Irwin, M. (2016). "The feeble giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater". Monthly Notices of the Royal Astronomical Society. 459 (3): 2370–2378. arXiv:1601.07178. Bibcode:2016MNRAS.459.2370T. doi:10.1093/mnras/stw733.
- ^ a b c Croswell, Ken (14 April 2016). "Never-before-seen galaxy spotted orbiting the Milky Way". New Scientist. Retrieved 14 April 2016.
- ^ Howard, Jacqueline (2016-04-16). "Elusive Dwarf Galaxy Found Orbiting Our Milky Way". Huffington Post. Retrieved 2016-04-19.
- ^ a b Ji, Alexander P.; Koposov, Sergey E.; Li, Ting S.; Erkal, Denis; Pace, Andrew B.; Simon, Joshua D.; Belokurov, Vasily; Cullinane, Lara R.; Da Costa, Gary S.; Kuehn, Kyler; Lewis, Geraint F.; MacKey, Dougal; Shipp, Nora; Simpson, Jeffrey D.; Zucker, Daniel B.; Hansen, Terese T.; Bland-Hawthorn, Joss; S5 Collaboration (2021). "Kinematics of Antlia 2 and Crater 2 from the Southern Stellar Stream Spectroscopic Survey (S 5)". The Astrophysical Journal. 921 (1): 32. arXiv:2106.12656. Bibcode:2021ApJ...921...32J. doi:10.3847/1538-4357/ac1869. S2CID 235624056.
External links[edit]
2016 in space | ||
|---|---|---|
Space probe launches  |
|    |
| Impact events | ||
| Selected NEOs | ||
| Exoplanets |
| |
| Discoveries |
| |
| Novae | ||
| Comets | ||
| Space exploration | ||
| Location | Milky Way → Milky Way subgroup → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → KBC Void → Observable universe → Universe Each arrow (→) may be read as "within" or "part of". |  | |||||
|---|---|---|---|---|---|---|---|
| Structure |
| ||||||
| Satellite galaxies | |||||||
| Related | |||||||
 | This elliptical galaxy article is a stub. You can help Wikipedia by expanding it. |