NGC 330 is an open cluster in the Small Magellanic Cloud. It is located in the constellationTucana. It was discovered on 1 August 1826 by James Dunlop. It was described by Dreyer as "a globular cluster, very bright, small, a little extended, stars from 13th to 15th magnitude."[4] At an aperture of 31.0 arcseconds, the apparent V-band magnitude is 9.60, but at this wavelength, it also has 0.36 magnitudes of interstellar extinction.[2]
NGC 330 is quite young, at about 40 million years old, and has a large proportion of Be stars.[5] Its estimated mass is 5.4×104M☉, and its total luminosity is 8.93×105L☉, leading to a mass-to-luminosity ratio of 0.06 M☉/L☉.[2] All else equal, older star clusters have higher mass-to-luminosity ratios; that is, they have lower luminosities for the same mass.[2] About 34% of the massive star population in NGC 330 is estimated to be in a close binary star system; this is lower than clusters in the Large Magellanic Cloud and the Milky Way, but it is unknown if this is because NGC 330 is metal-poor or is older than the compared clusters.[5]
^ abBodensteiner, J.; Sana, H.; Wang, C.; Langer, N.; Mahy, L.; Banyard, G.; de Koter, A.; de Mink, S. E.; Evans, C. J.; Götberg, Y.; Patrick, L. R.; Schneider, F. R. N.; Tramper, F. (2021). "The young massive SMC cluster NGC 330 seen by MUSE. II. Multiplicity properties of the massive-star population". Astronomy & Astrophysics. 652: 18. arXiv:2104.13409. Bibcode:2021A&A...652A..70B. doi:10.1051/0004-6361/202140507. S2CID207852580. A70.