NGC 5617
NGC 5617 | |
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Centaurus | |
NGC 5617 is an
Observation history
It was discovered by James Dunlop in 1826. He described it on May 8, 1826 as "a cluster of small stars of mixed magnitudes, considerably congregated towards the centre, 4' or 5' in diametre" and added it to his catalog as number 302. John Herschel described as "Class IV object, very rich; irregularly round; pretty much compressed in the middle but scattered at borders; 15'; there are three stars of 10th magnitude, 5 or 6 stars of 11th magnitude; the rest below 11th" and added it to General Catalogue as No. 3570. In the New General Catalogue it is described as "large (10'), richer in stars to the west (about 80 total), with a compressed middle. It contains stars of magnitude 8 and fainter."[4]
Characteristics
NGC 5617 is located nearly 2 kpc (6.500 light years) away from Earth, at the further border of
There are 175 probable member stars within the angular radius of the cluster and 65 within the central part of the cluster. The tidal radius of the cluster is 7.4 - 10.2 parsecs (24 - 33 light years) and represents the average outer limit of NGC 5617, beyond which a star is unlikely to remain gravitationally bound to the cluster core.
NGC 5617, along with its companion Trumpler 22, appear to be dynamically relaxed, with massive stars concentrated near the center and less massive stars in the periphery.[8]
Relation with Trumpler 22
NGC 5617 appears to be gravitationally bound to Trumpler 22.[10] The two clusters share similar radial velocities (-38.63 ± 2.25 km/s for NGC 5617 and -38.46 ± 2.08 km/s for Trumpler 22), mean metallicity (-0.18 ± 0.02 for NGC 5617 and-0.17 ± 0.04 for Trumpler 22), similar abundances across various elements, and have similar age, forming a primordial binary cluster pair.[7] Their orbits were initially almost circular and their separation less than 20 pc.[10]
References
- ^ a b c "NGC 5617". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-06-19.
- ^ S2CID 118548517.
- ^ "WEBDA: page for open cluster NGC 5617". www.univie.ac.at.
- ISBN 9781107015012.
- ^ S2CID 118380638.
- S2CID 2733862.
- ^ S2CID 118412915.
- ^ .
- ISSN 1021-2043.
- ^ S2CID 118340631.
External links
- NGC 5617 on