Young open cluster NGC 3293 and its relation to Car OB1 and the Carina Nebula complex
UBVRI photoelectric photometry and MK spectral classifications are presented for a large number of stars in the young cluster NGC 3293 and its surroundings (Car OB1). Over 70 cluster members with spectral types earlier than approx.B9 have been identified, and star counts indicate that the expected number of members brighter than Vapprox. =18 is 297 +- 9. Reddenings range between E/sub B/-V=0.20 and 0.46 for cluster members, but are higher for some outlying association stars. The cluster appears to lie just in front of a dense dust lane, which itself appears to be part of the dust complex emanating from the center of the Carina Nebula. Main-sequence fitting provides a reliable distance estimate for the cluster of 2.5 +- 0.2 kpc; other members of the Carina OB1 complex (Tr 14, Tr 15, Tr 16, Cr 228, NGC 3324, and IC 2581) have similar distances, and result in a mean distance to the complex of 2.7 +- 0.2 kpc. An age of 5 x 10/sup 6/ yr is derived for NGC 3293. An interesting gap in the distribution os cluster stars between (B-V)/sub 0/=-0.16 and -0.18 may be related to the early post-main-sequence evolution of these objects. Most of the cluster and association members appear to obey a normal reddening law characterized by R=3.1. A few objects, notably stars in reflection nebulae and others probably associated with the dust cloud just behind the cluster, seem to suffer from anomalous extinction. The oldest subgroup of the carina OB1 complex (IC 2581/NGC 3293; age 5 x 10/sup 6/ yr) lies at one edge of the complex, and the youngest (Tr 14/16; age approx.10/sup 6/ yr) at the other, separated by a projected distance of approx.130 pc. The number of stars per subgroup, however, is much larger in Carina than in any local association, and the age gradient is not so steep. If star formation is considered as propagating from IC 2581/NGC 3293 to Tr 14/16, its propagation velocity is approx.25 to 35 km s/sup -1/ in the direction of increasing galactic longitude.
- Research Organization:
- David Dunlap Observatory, University of Toronto, Richmond Hill, Ontario L4C 4Y6, Canada
- OSTI ID:
- 5124588
- Journal Information:
- Astron. J.; (United States), Vol. 85:9
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
MILKY WAY
STAR CLUSTERS
AGE ESTIMATION
DISTANCE
PHOTOMETRY
STAR EVOLUTION
COSMIC DUST
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DUSTS
GALAXIES
GIANT STARS
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640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
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