Palomar 12 by Hubble Space Telescope, 3.36′ view
|Observation data (J2000 epoch)|
|Right ascension||21h 46m 38.84s|
|Declination||–21° 15′ 09.4″|
|Distance||63.6 ± 2.9 kly (19.50 ± 0.89 kpc)|
|Apparent magnitude (V)||11.99|
|Apparent dimensions (V)||17′.4|
|Radius||162 ± 8 ly|
|Estimated age||6.5 Gyr|
|Other designations||GCl 123|
First discovered on the National Geographic Society – Palomar Observatory Sky Survey plates by Robert G. Harrington and Fritz Zwicky, it was catalogued as a globular cluster. However Zwicky came to believe this was actually a nearby dwarf galaxy in the Local Group. It is a relatively young cluster, being about 30% younger than most of the globular clusters in the Milky Way. It is metal-rich with a metallicity of [Fe/H] ~= -0.8. It has an average luminosity distribution of Mv = -4.48.
Based on proper motion studies, this cluster was first suspected in 2000 to have been captured from the Sagittarius dwarf galaxy about 1.7 Ga ago. It is now generally believed to be a member of the Sagittarius dwarf galaxy (Cohen 2004, Sbordone et al. 2006). It is estimated to be 6.5 Gyr old.
- distance × sin( diameter_angle / 2 ) = 162 ly. radius
- Simbad reference data
- SEDS: Palomar 12, Capricornus Dwarf
- Palomar 12 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images