NGC 265 is an open cluster of stars in the southern constellation of Tucana. It is located in the Small Magellanic Cloud,[4] a nearby dwarf galaxy. The cluster was discovered by English astronomer John Herschel on April 11, 1834. J. L. E. Dreyer described it as, "faint, pretty small, round", and added it as the 265th entry in his New General Catalogue.[6]

NGC 265
A Hubble Space Telescope (HST) image of NGC 265.
Credit: HST/NASA/ESA.
Observation data (J2000 epoch)
Right ascension00h 47m 35.8s[1]
Declination−73° 45′ 11″[1]
Distance200 kly[2]
Apparent dimensions (V)0.6[3]
Physical characteristics
Mass4,200±900[3] M
Radius47 ly (14.5 pc)[3]
Estimated age250±120 Myr[4]
Other designationsCl Lindsay 34, ESO 29-14, SMC−OGLE 39[5]
Associations
ConstellationTucana
See also: Open cluster, List of open clusters

This cluster has an angular core radius of 18″ and a physical radius of approximately 47 ly.[3] It has a combined 4,200[3] times the mass of the Sun and is around 250 million years old.[4] The metallicity of the cluster – what astronomers term the abundance of elements with higher atomic number than helium – is at around −0.62, or only 24% of that in the Sun. The turn-off mass for the cluster, when a star of that mass begins to evolve off the main sequence into a giant, is about 4.0 to 4.5 M.[7]

See also

edit

References

edit
  1. ^ a b Sulentic, Jack W.; et al. (1973). The revised new catalogue of nonstellar astronomical objects. Tucson: University of Arizona Press. Bibcode:1973rncn.book.....S. See the Vizier VII/1B/catalog entry for NGC 265.
  2. ^ "Magellanic gemstone in the southern sky [NGC 265]". Space Telescope Website. Retrieved 2009-03-02.
  3. ^ a b c d e Nayak, P. K.; et al. (September 2018). "Star clusters in the Magellanic Clouds. II. Age-dating, classification, and spatio-temporal distribution of the SMC clusters". Astronomy & Astrophysics. 616: 24. arXiv:1804.00635. Bibcode:2018A&A...616A.187N. doi:10.1051/0004-6361/201732227. S2CID 55901741. A187.
  4. ^ a b c Piatti, Andrés E.; et al. (May 2007). "Young star clusters immersed in intermediate-age fields in the Small Magellanic Cloud". Monthly Notices of the Royal Astronomical Society. 377 (1): 300–316. Bibcode:2007MNRAS.377..300P. doi:10.1111/j.1365-2966.2007.11604.x. hdl:11336/21054.
  5. ^ "NGC 265". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2007-04-17.
  6. ^ Seligman, Courtney. "NGC Objects: NGC 2600 - 2649". Celestial Atlas. Retrieved 2020-09-06.
  7. ^ Chiosi, E.; Vallenari, A. (April 2007). "Three clusters of the SMC from ACS/WFC HST archive data: NGC 265, K 29 and NGC 290 and their field population". Astronomy and Astrophysics. 466 (1): 165–179. arXiv:astro-ph/0702281. Bibcode:2007A&A...466..165C. doi:10.1051/0004-6361:20066834. S2CID 7596416.
edit