NGC 346

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.

NGC 346
James Webb Space Telescope image of NGC 346
Observation data (J2000 epoch)
Right ascension	00h 59m 05.090s[1]
Declination	−72° 10′ 33.24″[1]
Distance	210,000 light-years
Physical characteristics
H II region
Other designations	ESO 51-10,[2] N66
Associations
Constellation	Tucana[3]
See also: Open cluster, List of open clusters

Description

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]

Image Gallery

• 
  Image of NGC 346 with a 30 arcminute wide field of view showing the wispy nebular structure around it.
• 
  NGC 346 imaged by the Hubble Space Telescope
• 
  James Webb Space Telescope image of star formation in NGC 346

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

• List of most massive stars