1997A&A...325..585V -
Astronomy and Astrophysics, volume 325, 585-600 (1997/9-2)
Obscured Asymptotic Giant Branch stars in the Magellanic Clouds. III. New IRAS counterparts.
VAN LOON J.T., ZIJLSTRA A.A., WHITELOCK P.A., WATERS L.B.F.M., LOUP C. and TRAMS N.R.
Abstract (from CDS):
We have searched for near-infrared stellar counterparts of IRAS point sources in the Large Magellanic Cloud (LMC), in J- and K-bands. This resulted in the detection of 21 counterparts, of which 19 are new discoveries. Using colour-magnitude and colour-colour diagrams, we identify 13 Asymptotic Giant Branch (AGB) stars with thick circumstellar dust envelopes, 7 possible early post-AGB stars or stars recovering from a thermal pulse, and 1 red supergiant or foreground star. For 10 of the IRAS targets we do not succeed in detecting and/or identifying a near-infrared counterpart. We serendipitously detect 14 other red sources, of which 2 are known Long Period Variables, and a few galaxies. The near-infrared and optical colours of the galaxies may indicate considerable interstellar extinction through the LMC, as much as AV∼2-4mag. The relative number of AGB carbon stars over oxygen stars is shown to decrease as the luminosity increases. Yet amongst the faintest mass-losing AGB stars oxygen-rich stars still exist, which puts constraints on current convection theories that predict the occurrence of third dredge-up and Hot Bottom Burning. We investigate the nature of some LMC stars that have infrared properties very similar to suspected Galactic post-AGB stars.
Abstract Copyright:
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Journal keyword(s):
stars: mass loss - stars: AGB and post-AGB - dust, extinction - Magellanic Clouds - infrared: galaxies - infrared: stars
Nomenclature:
Table 1: LI-LMC NNNNa N=14
Simbad objects:
62
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