Wednesday, November 16, 2011

1111.3367 (Colin Littlefield et al.)

Discovery of a Wolf-Rayet Star Through Detection of its Photometric Variability    [PDF]

Colin Littlefield, Peter Garnavich, G. H. Howie Marion, Jozsef Vinko, Colin McClelland, Terrence Rettig, J. Craig Wheeler
We report the serendipitous discovery of a heavily reddened Wolf-Rayet star that we name WR142b. While photometrically monitoring a cataclysmic variable, we detected weak variability in a nearby field star. Low-resolution spectroscopy revealed a strong emission line at 7100 Ang., suggesting an unusual object and prompting further study. A spectrum taken with the Hobby-Eberly Telescope confirms strong HeII emission and a NIV 7112 Ang. line consistent with a nitrogen-rich Wolf-Rayet star of spectral class WN6. Analysis of the HeII line strengths reveals no detectable hydrogen in WR142b. A blue-sensitive spectrum obtained with the Large Binocular Telescope shows no evidence for a hot companion star. The continuum shape and emission line ratios imply a reddening of E(B-V)=2.2 to 2.5 mag. If not for the dust extinction, this new Wolf-Rayet star could be visible to the naked eye.
View original: http://arxiv.org/abs/1111.3367

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