The stellar content of NGC 346 - A plethora of O stars in the SMC

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Astronomical Journal; (USA)

DOI:https://doi.org/10.1086/115217· OSTI ID:5125825

Massey, P; Parker, J W; Garmany, C D ^[1]

---

1. Kitt Peak National Observatory, Tucson, AZ (USA) Joint Institute for Laboratory Astrophysics, Boulder, CO (USA)

The stellar content of NGC 346, the largest and brightest H II region in the SMC, was investigated using the results of CCD UBV photometry and spectroscopy. Spectra of 42 blue stars were classified, showing that 33 are of the O type, of which 11 are of type O6.5 or earlier, which is as many early-type O stars known in the rest of the SMC. The results identify 25-30 NGC 346 stars more massive than 25 solar masses, and six stars more massive than 40 solar masses, indicating that the upper-mass cutoff to the IMF is not lower in the SMC than in the Galaxy or the LMC. The presence of evolved 15 solar-mass stars in the NGC 346 indicates that some massive stars formed 15 million yr ago. The results of spatial distribution suggest that star formation began at the southwest side of the association and has spread to where the central cluster lies now, providing an example of sequential star formation in the SMC. 69 refs.

• OSTI ID: 5125825
• Journal Information: Astronomical Journal; (USA), Journal Name: Astronomical Journal; (USA) Vol. 98; ISSN 0004-6256; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
CATALOGS
CLASSIFICATION
COSMIC RADIO SOURCES
DOCUMENT TYPES
GALACTIC EVOLUTION
GALAXIES
H2 REGIONS
INTERSTELLAR SPACE
MAGELLANIC CLOUDS
MAIN SEQUENCE STARS
MASS
MORPHOLOGY
NEBULAE
SPACE
SPECTROPHOTOMETRY
STAR EVOLUTION
STARS
WOLF-RAYET STARS