NGC 6352 (also known as Caldwell 81) is a globular cluster of stars in the southern constellation of Ara, located approximately 18.3 kly[3] from the Sun. It was discovered by Scottish astronomer James Dunlop on May 14, 1826.[10] The cluster has a Shapley–Sawyer Concentration Class of XI:.[1] A telescope with a 15 cm (5.9 in) aperture is required to resolve the stars within this loose cluster.[4]
NGC 6352 | |
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Observation data (J2000 epoch) | |
Class | XI:[1] |
Constellation | Ara |
Right ascension | 17h 25m 29.11s[2] |
Declination | –48° 25′ 19.8″[2] |
Distance | 18.3 kly (5.6 kpc)[3] |
Apparent magnitude (V) | +7.8[4] |
Apparent dimensions (V) | 7.1′[5] |
Physical characteristics | |
Mass | 3.7×104[6] M☉ |
Tidal radius | 10.5″[7] |
Metallicity | = –0.70[8] dex |
Estimated age | 12.67 Gyr[8] |
Other designations | Caldwell 81, Cr 328, NGC 6352[9] |
This cluster is about 12.67[8] billion years old with two distinct stellar populations; the second generation is only around 10 million years younger than the first.[3] It lies approximately 13 kly (4 kpc) from the Galactic Center and 1.6 kly (0.5 kpc) from the galactic plane.[11] The orbital motion of this cluster through the Milky Way suggests it is a member of the bulge or disk population.[12] It is relatively metal-rich for an object of this class,[3] having a metallicity of –0.70.[8] The core radius is 49.8″[3] and the tidal radius is 10.5″.[7]