Astron. Astrophys. 349, 537-545 (1999)

Light variations of massive stars ( Cygni variables) ^*

XVII. The LMC supergiants R 74 (LBV), R 78, HD 34664 = S 22 (B[e]/LBV), R 84 and R 116 (LBV?)

A.M. van Genderen ¹ and C. Sterken  <sup>**  2

1</sup> Leiden Observatory, Postbus 9513, 2300RA Leiden, The Netherlands (genderen@strw.leidenuniv.nl)
² University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels, Belgium

Received 21 April 1999 / Accepted 3 June 1999

Abstract

Multi-colour photometry (Walraven system) of five super- and hypergiants in the LMC, viz. R 74, R 78, HD 34664, R 84 and R 116, is searched for variability and periods, and discussed. Apart from R 84, of which the claimed variability in the past must be due to a number of faint field stars at the edge of the apertures, all are variable.

R 74 and HD 34664 are weak-active LBVs with superimposed microvariations. HD 34664 is the second known B[e] star which is also an LBV. The first reported one is R 4 in the SMC. This could alter some views on the evolutionary history of B[e] stars and LBVs.

R 78 is an  Cyg variable, but presumably no LBV. R 116 appears to be a close counterpart of the galactic ex-/dormant LBV  Sco, also showing an intricate  Cyg-type multi-period microvariability.

Key words: stars: individual: R 116 = HDE 269700; R 74 = HDE 268939; R 78 = HDE 269050; R 84 = HDE 269227; S 22 = HD 34664 galaxies: Magellanic Clouds

* Based on observations obtained at the European Southern Observatory at La Silla, Chile
** Belgian Fund for Scientific Research (FWO)

Send offprint requests to: A.M. van Genderen

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and reductions
• 3. The light- and colour curves, the period analysis
  • 3.1. R 74 = HDE 268939, B Ie
  • 3.2. R 78 = HDE 269050, B0 Ia
  • 3.3. HD 34664 = S 22, B[e]0-0.5
  • 3.4. R 84 = HDE 269227, WN9
  • 3.5. R 116 = HDE 269 700, B1.5 Iaeq
• 4. Discussion and conclusions
  • 4.1. R 74 = HDE 268939
  • 4.2. R 78 = HDE 269050
  • 4.3. HD 34664 = S 22
  • 4.4. R 84 = HDE 269227
  • 4.5. R 116 = HDE 269700
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: September 2, 1999
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