Terzan 5
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Terzan 5 is a heavily obscured globular cluster belonging to the bulge (the central star concentration) of the Milky Way galaxy.[3] It was one of six globulars discovered by French[7] astronomer Agop Terzan in 1968[8] and was initially labeled Terzan 11. The cluster was cataloged by the Two-Micron Sky Survey as IRC–20385.[9] It is situated in the Sagittarius constellation in the direction of the Milky Way's center. Terzan 5 probably follows an unknown complicated orbit around the center of the galaxy, but currently it is moving towards the Sun with a speed of around 90 km/s.[6]
Quick Facts Observation data (J2000 epoch), Class ...
Terzan 5 | |
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Observation data (J2000 epoch) | |
Class | G2[1] |
Constellation | Sagittarius |
Right ascension | 17h 48m 05s[2] |
Declination | −24° 46′ 48″[2] |
Distance | 18.8 ± 1.6 kly[note 1] (5.9 ± 0.5 kpc[4]) |
Apparent magnitude (V) | 12.8[1] |
Apparent dimensions (V) | 1′02″ (half-mass diameter)[4] |
Physical characteristics | |
Mass | ~2×106[4] M☉ (4 × 1036 kg) |
Radius | 2.7 ly[note 2] |
VHB | 22.5[3] |
Metallicity | = −0.21 dex |
Estimated age | 12 Gyr[6] |
Notable features | Possibly the core of a disrupted dwarf galaxy |
Other designations | Ter 5, IRC–20385 |
See also: Globular cluster, List of globular clusters |
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