Q872164

Also known as New General Catalogue 121

globular cluster in the constellation Tucana

Key facts

Constellation: Tucana
Right ascension: 00 26 49.0
Declination: −71 ° 32 ′ 10 ″
Distance: 200 kly (60 kpc )
Mass: 3.6 +0.9, −0.7 × 10 M ☉
Radius: 98 ly (30.2 pc)
Tidal radius: 143″
Metallicity: [ Fe/H ] = −1.28 ± 0.03 dex
Estimated age: 10.5 ± 0.5 Gyr

via Wikipedia infobox

Wikidata facts

Image: NGC 121 Hubble WikiSky.jpg

via Wikidata · CC0

Article

NGC 121 is a globular cluster of stars in the southern constellation of Tucana. It is the oldest globular cluster in the Small Magellanic Cloud (SMC), which is a dwarf satellite galaxy of the Milky Way. This cluster was first discovered by English astronomer John Herschel on September 20, 1835. The compiler of the New General Catalogue, Danish astronomer John Louis Emil Dreyer, described this object as "pretty bright, pretty small, little extended, very gradually brighter middle". The cluster is located at a distance of around 200,000 light-years (60 kpc) from the Sun.

This cluster forms part of the West Halo, a region that is moving outward with respect to the rest of the SMC. It is located about 2.3° northwest of the SMC galactic center. The cluster mass is 3.6×10 times the mass of the Sun. The angular half-light radius of this cluster is 27.1″, and the tidal radius is 143″. It is positioned about ~32′ from the massive globular cluster 47 Tucanae, which has a tidal radius of 42.86′.