NGC 346
James Webb Space Telescope image of NGC 346
Observation data (J2000 epoch)
Right ascension00h 59m 05.090s[1]
Declination−72° 10′ 33.24″[1]
Distance210,000 light-years
Physical characteristics
H II region
Other designationsESO 51-10,[2] N66
Associations
ConstellationTucana[3]

NGC 346 is a young[4] open cluster of stars with associated nebula located in the Small Magellanic Cloud (SMC) that appears in the southern constellation of Tucana. It was discovered August 1, 1826 by Scottish astronomer James Dunlop. J. L. E. Dreyer described it as, "bright, large, very irregular figure, much brighter middle similar to double star, mottled but not resolved".[5] On the outskirts of the cluster is the multiple star system HD 5980,[6] one of the brightest stars in the SMC.

This cluster is located near the center of the brightest H II region in the SMC, designated N66.[7] This is positioned in the northeast section of the galactic bar.[8] Stellar surveys have identified 230 massive OB stars in the direction of this cluster.[4] 33 of the cluster members are O-type stars, with 11 of type O6.5 or earlier.[8] The inner 15 pc radius of the cluster appears centrally condensed, while the area outside that volume is more dispersed.[9] The youngest cluster members near the center have ages of less than two million years,[7] and observations suggests the cluster is still engaged in high mass star formation.[7] The cluster star formation rate is estimated at (4±1)×10−3 M☉ yr−1.[9]

Prominent stars[10]
Walborn ELS MPG NMC SSN Spectral
type		 Effective
temperature (K)		 Absolute
magnitude		 Bolometric
magnitude		 Mass
(M☉)
207758 755
(HD 5980/AB5)		 LBV
WN4
OI		 45,000
45,000
34,000		 −7.1
(−8.1) −6.8
−6.7		 −11.135
−10.885
−9.885		 61
66
34
1 435 26 7 O5.5If 43,400 −6.7 −10.7 91
1 789 5 O7If 38,900 −7 −10.7 85
3 355 29 9 O3V 51,300 −5.7 −10.3 76
6 7 324 32 13 O4V 48,600 −5.2 −9.6 54
4 342 30 11 O5.5V 44,900 −5.5 −9.7 53
368 28 15 O5.5V 44,900 −5 −9.2 43
2 470 25 O8.5III 35,700 −5.4 −8.9 34

See also

References

  1. 1 2 Sturm, R.; et al. (October 2013). "The XMM-Newton survey of the Small Magellanic Cloud: The X-ray point-source catalogue". Astronomy & Astrophysics. 558: 31. arXiv:1307.7594. Bibcode:2013A&A...558A...3S. doi:10.1051/0004-6361/201219935. S2CID 118620464. A3.
  2. ↑ "NGC 346". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2007-04-17.
  3. ↑ "Hubble Heritage Site". Results for NGC 346. Retrieved 2007-04-03.
  4. 1 2 Dufton, P. L.; et al. (February 2020). "The NGC 346 massive star census. Nitrogen abundances for apparently single, narrow lined, hydrogen core burning B-type stars". Astronomy & Astrophysics. 634: 15. arXiv:1912.07539. Bibcode:2020A&A...634A...6D. doi:10.1051/0004-6361/201936921. S2CID 209376523. A6.
  5. ↑ Seligman, Courtney. "New General Catalogue objects: NGC 300 - 349". cseligman.com. Retrieved 2020-09-17.
  6. ↑ Nazé, Y.; et al. (November 2002). "An X-Ray Investigation of the NGC 346 Field in the Small Magellanic Cloud I. The Luminous Blue Variable HD 5980 and the NGC 346 Cluster". The Astrophysical Journal. 580 (1): 225–234. arXiv:astro-ph/0208289. Bibcode:2002ApJ...580..225N. doi:10.1086/343079. S2CID 118907796.
  7. 1 2 3 Dufton, P. L.; et al. (June 2019). "A census of massive stars in NGC 346. Stellar parameters and rotational velocities". Astronomy & Astrophysics. 626: 28. arXiv:1905.03359. Bibcode:2019A&A...626A..50D. doi:10.1051/0004-6361/201935415. S2CID 148571638. A50.
  8. 1 2 Rubio, M.; et al. (July 2018). "Massive young stellar objects in the N 66/NGC 346 region of the SMC". Astronomy & Astrophysics. 615: 9. arXiv:1803.10833. Bibcode:2018A&A...615A.121R. doi:10.1051/0004-6361/201730487. S2CID 119190580. A121.
  9. 1 2 Hony, S.; et al. (April 2015). "Star formation rates from young-star counts and the structure of the ISM across the NGC 346/N66 complex in the SMC". Monthly Notices of the Royal Astronomical Society. 448 (2): 1847–1862. arXiv:1501.03634. Bibcode:2015MNRAS.448.1847H. doi:10.1093/mnras/stv107.
  10. ↑ Massey, Philip; Waterhouse, Elizabeth; DeGioia-Eastwood, Kathleen (May 2000). "The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turnoffs. I. Results from 19 OB Associations in the Magellanic Clouds". The Astronomical Journal. 119 (5): 2214–2241. arXiv:astro-ph/0002233. Bibcode:2000AJ....119.2214M. doi:10.1086/301345. ISSN 0004-6256. S2CID 16891188.
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