2018MNRAS.474.1412G


Query : 2018MNRAS.474.1412G

2018MNRAS.474.1412G - Mon. Not. R. Astron. Soc., 474, 1412-1425 (2018)

Optical spectroscopy of the blue supergiant Sk-69° 279 and its circumstellar shell with SALT.

GVARAMADZE V.V., KNIAZEV A.Y., MARYEVA O.V. and BERDNIKOV L.N.

Abstract (from CDS):

We report the results of optical spectroscopy of the blue supergiant Sk-69° 279 and its circular shell in the Large Magellanic Cloud (LMC) with the Southern African Large Telescope (SALT). We classify Sk-69° 279 as an O9.2 Iaf star and analyse its spectrum by using the stellar atmosphere code CMFGEN, obtaining a stellar temperature of ≃30 kK, a luminosity of log (L*/ L) = 5.54, a mass-loss rate of log({dot}M/ M yr–1) = -5.26, and a wind velocity of 800km s–1. We found also that Sk-69° 279 possesses an extended atmosphere with an effective temperature of ≃24 kK and that its surface helium and nitrogen abundances are enhanced, respectively, by factors of ≃2 and 20-30. This suggests that either Sk-69° 279 was initially a (single) fast-rotating ( >= 400 km s^- 1^) star, which only recently evolved off the main sequence, or that it is a product of close binary evolution. The long-slit spectroscopy of the shell around Sk-69° 279 revealed that its nitrogen abundance is enhanced by the same factor as the stellar atmosphere, which implies that the shell is composed mostly of the CNO processed material lost by the star. Our findings support previous propositions that some massive stars can produce compact circumstellar shells and, presumably, appear as luminous blue variables while they are still on the main sequence or have only recently left it.

Abstract Copyright: © 2017 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): circumstellar matter - stars: emission-line, Be - stars: fundamental parameters - stars: individual: Sk-69deg 279 - stars: massive - supergiants

Simbad objects: 9

goto Full paper

goto View the references in ADS

Number of rows : 9
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 6023 1
2 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 15536 1
3 KMHK 1240 As* 05 41 33.1 -69 40 01           ~ 9 0
4 SK -69 279 Em* 05 41 44.6557001998 -69 35 14.904660652 12.079 12.787 12.842 13.03 12.619 OB 46 0
5 HD 90177 s*b 10 22 53.8426931454 -59 37 28.361118869 9.16 9.66 8 8.15   LBV 311 0
6 NAME Sher 25 star * 11 15 07.6444076894 -61 15 17.608695337   13.63 12.27     B1.5Iab 73 1
7 IRAS 15127-5811 s*b 15 16 41.0006516530 -58 22 25.958980212   15.34 13.40 12.500 10.91 B1Ia 9 0
8 HD 168625 s*b 18 21 19.5486475779 -16 22 26.077308888 10.15 9.78 8.37 8.76   B6Iap 258 2
9 TYC 3159-6-1 * 20 18 40.3673772505 +41 32 45.105229448   12.51 10.88   8.52 O9.5-O9.7Ib 6 0

To bookmark this query, right click on this link: simbad:objects in 2018MNRAS.474.1412G and select 'bookmark this link' or equivalent in the popup menu


2021.09.23-22:32:23

© Université de Strasbourg/CNRS

    • Contact