Young SMC Cluster NGC 330

Journal Article · Mon Jul 01 04:00:00 EDT 1985 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/113827· OSTI ID:5660327

Carney, B W; Janes, K A; Flower, P J

We report the results obtained from deep photoelectric and photographic UBV photometry, low-resolution spectroscopy, and DDO and infrared photometry for stars in and around the young SMC cluster NGC 330. The color-magnitude diagram, reaching to Vapprox.20 mag, shows a well-defined main sequence, a group of blue supergiants, a group of red supergiants between B-V = 1X2 and 1X6 about one magnitude fainter, and an empty Hertzsprung gap. The surrounding field is a composite of a very gold population resembling galactic globular clusters and a very young population (but older than the cluster itself). The spectroscopy, together with UBV and infrared photometry, indicate E(B-V) = 0X03. The photometry and the spectroscopy together are consistent in showing a rather low metallicity, but calibration difficulties we discuss prevent a quantitative measure. Either the overall metallicity is less than one-tenth, or the relative abundances of the CNO elements are substantially less than the solar ratios. We have also compared synthetic color-magnitude diagrams with the observed diagram, and we find the best fit for a theoretical cluster using a solar composition and an age of 12 x 10/sup 6/ yr, with the field being about 50% older. Models with lower abundances do not match the observed diagrams at any age; a decreased opacity would permit a match between the metal-poor models and the data.

• Research Organization: Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27514
• OSTI ID: 5660327
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 90:7; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AGE ESTIMATION
CALIBRATION
CHEMICAL COMPOSITION
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
GALAXIES
H2 REGIONS
INFRARED RADIATION
MAGELLANIC CLOUDS
PHOTOMETRY
RADIATIONS
SPECTROSCOPY
STAR CLUSTERS
STAR EVOLUTION