GCIRS34W: An irregular variable in the Galactic Centre

Abstract

We report the results of time-resolved photometric and spectroscopic near-infrared observations of the Ofpe/WN9 star and LBV candidate GCIRS34W in the Galactic Centre star cluster. Diffraction limited resolution photometric observations obtained in H and K bands show a strong, non-periodic variability on time scales from months to years in both bands accompanied by variations of the stellar colour. Three K band spectra obtained in 1996, 2003 and 2004 with integral field spectrometers are identical within their accuracies and exclude significant spectroscopic variability. The most probable explanation of the stellar photometric variability is obscuration by circumstellar material ejected by the star. The approximated position of GCIRS34W in a HR diagram is located between O supergiants and LBVs, suggesting that this star is a transitional object between these two phases of stellar evolution.

6 pages, 3 figures, accepted by A&A

References in corpus (8)

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Cited by in corpus (8)

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• GCIRS16SW: a massive eclipsing binary in the Galactic Center
• Photometric Stellar Variability in the Galactic Center
• A serendipitous survey for variability amongst the massive stellar population of Westerlund 1
• New Galactic Wolf-Rayet stars, and candidates. An annex to The VIIth Catalogue of Galactic Wolf-Rayet Stars
• An updated stellar census of the Quintuplet cluster
• Radial Velocities of Stars in the Galactic Center