NGC 5897

NGC 5897 is a globular cluster in the constellation Libra. This satellite of the Milky Way, which is quite remote (located about 41,000 light years away), has a diameter of over 170 light years. With its Shapley–Sawyer Concentration Class of XI, it has very low star density even in its center.[3]

NGC 5897
The globular cluster NGC 5897 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
Class	XI[1]
Constellation	Libra
Right ascension	15h 17m 24.40s[2]
Declination	−21° 00′ 36.4″[2]
Distance	24.1 kly (7.4 kpc)[2]
Apparent magnitude (V)	8.52[2]
Physical characteristics
Radius	6.3' x 6.3'[3]
Metallicity	${\displaystyle {\begin{smallmatrix}\left[{\ce {Fe}}/{\ce {H}}\right]\end{smallmatrix}}}$ = -2.04±0.15[4] dex
Other designations	GCl 33, C 1514-208[2]

The stars of the cluster have only 0.91% of the Sun's metallicity,[5] while the abundance of elements produced by the alpha process is roughly 5 times larger.[4] This means that the cluster formed in a time before the galaxy formed a disk and spiral arms. However, some of the stars are apparently younger, indicating multiple star-forming epochs.[4]

NGC 5897 has a diameter of 12.6 arcminutes and an apparent magnitude of 8.5.