| NGC 1850 | |
|---|---|
 AHubble Space Telescope (HST) image of NGC 1850. | |
| Observation data (J2000.0epoch) | |
| Constellation | Dorado |
| Right ascension | 05h 08m 50.190s[1] |
| Declination | −68° 45′ 35.65″[1] |
| Apparent magnitude(V) | 9.0 |
| Apparent dimensions(V) | 3.4′ |
| Physical characteristics | |
| Mass | 41,700+10,800 −8,600[2] M☉ |
| Radius | 16.2 ± 1.1 ly (4.97 ± 0.35 pc)[2] |
| Tidal radius | 9.82 ± 0.39 ly (3.01 ± 0.12 pc)[2] |
| = −0.3[2]dex | |
| Estimated age | ~100 Myr[2] |
| Other designations | NGC 1850, ESO 056-SC070, h 2780, GC 1060 |
| See also:Globular cluster,List of globular clusters | |
NGC 1850 is adouble cluster and asuper star cluster in theDorado constellation, located in the northwest part[3] of the bar of theLarge Magellanic Cloud,[4] at a distance of 168 kly (51.5 kpc) from theSun.[citation needed] It was discovered by Scottish astronomerJames Dunlop in 1826.
This is an unusual cluster system because the main distribution of stars is like aglobular cluster, but unlike the globular clusters of theMilky Way it is composed of young stars. The only similar object in the Milky Way isWesterlund 1.[5] The main cluster has the appearance of a globular cluster with an age of50±10 Myr. The second is a more loosely distributed sub-cluster with an age of4.3±0.9 Myr,[4] located at anangular separation of30″ to the west of the main cluster.[6] There are indications of interactions between the two, with the larger component being irregular and showing a tail toward the northwest.[3]
The main cluster is around 100 million years old,[2] with atidal radius of 10 light years and an overall radius of 16 light years.[2] It has an estimated mass of 42,000 times themass of the Sun.[2] The stellar component is split into twomain sequence populations, with about a quarter of the stars in a blue (hotter) group and the rest in a redder (cooler) population.[2] The cluster is embedded in an ionization region designated Henize 103.[7]
The much younger subcluster, often designated NGC 1850A,[3] contains a number of young, massiveO/B-type stars that are on or near themain sequence, distributed up to1′ from the central clump. Seven subcluster members have masses of≥ 35 M☉, and two of those are≥ 50 M☉. Lower mass members up to~3 M☉ are still on thepre-main-sequence stage. The age distribution of the subcluster members indicate star formation has been active almost constantly since its formation. The eastern side of the cluster is more obscured and has fewer OB stars.[6]
In November 2021, astronomers usingMUSE on theVery Large Telescope reported the discovery of a stellar-massblack hole in NGC 1850 by viewing its influence on the motion of a star in close proximity, the first direct dynamical detection of a black hole in a young massive cluster.[8]
Media related toNGC 1850 at Wikimedia Commons
