See also: Globular cluster, List of globular clusters
NGC 1851 (also known as Caldwell 73)[9] is a relatively massive[3] globular cluster located in the southern constellation of Columba. Astronomer John Dreyer described it as not very bright but very large, round, well resolved, and clearly consisting of stars.[4] It is located 39.5 kilolight-years from the Sun, and 54.1 kilolight-years from the Galactic Center.[3] The cluster is following a highly eccentric orbit through the galaxy, with an eccentricity of about 0.7.[10]
This object has a Shapley–Sawyer Concentration Class of II,[1] indicating a dense central concentration. It has one of the highest concentrations known for Galactic globular clusters.[3] The stellar components show two separate populations of subgiant stars, with the brighter branch being more concentrated in the outer regions of the cluster.[10] NGC 1851 is an estimated 9.2[6] billion years old with 551,000 times the mass of the Sun.[5]
The cluster is surrounded by a diffuse halo of stars that stretches outward to a radius of 240 pc or more. This feature, if combined with the lack of tidal tail or associated stream of stars, suggests the cluster may be a stripped dwarf galaxy nucleus, similar to Omega Centauri, that has been accreted by the Milky Way.[3] The tidal tail is still present though.[11] It is also possible the cluster is the result of the merger of two separate clusters, but the fact that they would need to have the same metallicity – what astronomers term the abundance of elements other than hydrogen and helium – makes this scenario less likely.[10]
PSR J0514-4002A is a millisecond pulsar in NGC 1851. It is orbiting a massive object that may also be a neutron star. The pair have an orbital period of 18.8 days with a large eccentricity of 0.89.[12] A nearby pulsar PSR J0514−4002E is orbiting a massive object which appears to occupy the "mass gap" between the heaviest neutron stars and the lightest black holes, making it an unusual star system which may be useful for studying theories of gravity.[13] The TRAPUM Large Survey Project using the MeerKAT radio telescope discovered thirteen new pulsars in the cluster, which consist of six isolated millisecond pulsars (MSPs) and seven binary pulsars, of which six are MSPs and one is mildly recycled. [14] 43 RR Lyrae variables have been discovered in the cluster, which show this to be an Oosterhoff type I cluster but having properties similar to type II. Two populations of horizontal branch stars have been observed, with the pair having an age difference of around two billion years.[15] Spectroscopic analysis of the red giant branch member stars suggests there are actually three different populations of stars in the cluster.[16]
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^Carballo-Bello, Julio A.; Martínez-Delgado, David; Navarrete, Camila; Catelan, Márcio; Muñoz, Ricardo R.; Antoja, Teresa; Sollima, Antonio (2017), "Tails and streams around the Galactic globular clusters NGC 1851, NGC 1904, NGC 2298 and NGC 2808", Monthly Notices of the Royal Astronomical Society, 474: 683–695, arXiv:1710.08927, doi:10.1093/mnras/stx2767
^Cite error: The named reference Ridolfi2019 was invoked but never defined (see the help page).
^Ewan D. Barr et al. A pulsar in a binary with a compact object in the mass gap between neutron stars and black holes. Science 2024; 383:275-279. doi:10.1126/science.adg3005
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NGC1851 (also known as Caldwell 73) is a relatively massive globular cluster located in the southern constellation of Columba. Astronomer John Dreyer...
members are Messier 2, Messier 56, Messier 75, Messier 79, NGC1851, NGC 2298, and NGC 5286. NGC 2808 is another globular-like cluster of the Sausage. It...
Globular clusters thought to be associated with the CMa include NGC1851, NGC 1904, NGC 2298 and NGC 2808, all of which may have been part of the galaxy's globular...
neutron stars and black holes. The pair are located in the globular cluster NGC1851. Two insect-like robots, a mini-bug and a water strider, are reported as...
"Tails and streams around the Galactic globular clusters NGC1851, NGC 1904, NGC 2298 and NGC 2808", Monthly Notices of the Royal Astronomical Society...
"Tails and streams around the Galactic globular clusters NGC1851, NGC 1904, NGC 2298 and NGC 2808", Monthly Notices of the Royal Astronomical Society...
1851 and catalogued as a nebula-type object. It has been monitored by multiple different telescopes since its discovery. Stoney first described NGC 3000...
"Tails and streams around the Galactic globular clusters NGC1851, NGC 1904, NGC 2298 and NGC 2808", Monthly Notices of the Royal Astronomical Society...
objects, such as the Hyades, the Double Cluster (NGC 869 and NGC 884), and the Sculptor Galaxy (NGC 253). The Messier catalogue was actually compiled...
Lopez chess openings ECO code Thyroid cancer ICD-10 code Caldwell 73 (NGC1851), a globular cluster in the constellation Columba This disambiguation page...
Astrosat, and directed by Sue Sudbury, was released. FUV Images of the NGC-1851 cluster Messier 74 captured by astrosat Spaceflight portal AstroSat-2 Indian...
galaxies. List of NGC objects (1–1000) List of NGC objects (1001–2000) List of NGC objects (2001–3000) List of NGC objects (3001–4000) List of NGC objects (4001–5000)...
of Stars (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects...
"Evidence Against Dark Matter Halos Surrounding the Globular Clusters MGC1 and NGC 2419". The Astrophysical Journal. 741 (2): 72. arXiv:1010.5783. Bibcode:2011ApJ...
1851. It is part of a small group of galaxies including NGC 2998, NGC 3002, NGC 3005, NGC 3008, and MCG+07-20-052. "Results for object NGC 3006 (NGC 3006)"...
NGC 3005 is an edge-on spiral galaxy in the constellation of Ursa Major, discovered by Bindon Stoney on January 25, 1851. It is a member of the NGC 2998...
Struve on April 28, 1851. NGC 4467 is a companion of Messier 49 and is a member of the Virgo Cluster. List of NGC objects (4001–5000) NGC 4464 "NASA/IPAC...
Bibcode:2013ApJ...767..101B. doi:10.1088/0004-637X/767/2/101. S2CID 73653979. "NGC 1841". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 16...
Messier 38 or M38, also known as NGC 1912 or Starfish Cluster, is an open cluster of stars in the constellation of Auriga. It was discovered by Giovanni...
February 26, 1851. The galaxy is a member of the Virgo Cluster. List of NGC objects (4001–5000) "NASA/IPAC Extragalactic Database". Results for NGC 4466. Retrieved...
March 1, 1851. List of the most distant astronomical objects List of NGC objects (5001–6000) "NASA/IPAC Extragalactic Database". Results for NGC 5609. Retrieved...