Palomar 6

Palomar 6 is a loose globular cluster in the constellation Ophiuchus that belongs to the Milky Way galaxy. It is a member of the Palomar Globular Clusters group. It is located about 25,000 light-years (7,700 parsecs) away from the Sun. It formed in what would become the bulge of the Milky Way. It is similar to other old-bulge globular clusters such as Messier 62, NGC 6522, NGC 6558, and Haute-Provence 1.

Palomar 6
Observation data (J2000 epoch)
Class	XI
Constellation	Ophiuchus
Right ascension	17h 43m 42.20s
Declination	−26° 13′ 21.0″
Distance	25.02 ± 0.62 kly (7.67 ± 0.19 kpc)
Physical characteristics
Mass	2.28×105 M☉
Metallicity	${\displaystyle {\begin{smallmatrix}\left[{\ce {Fe}}/{\ce {H}}\right]\end{smallmatrix}}}$ = –0.91 dex
Estimated age	12.4 ± 0.9 Gyr
Other designations	ESO 520-21, GCl 75, 1740-262

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, and is one of four globulars known to contain a planetary nebula.