%0 Generic %1 wu2014discovery %A Wu, Shi-Wei %A Bik, Arjan %A Henning, Thomas %A Pasquali, Anna %A Brandner, Wolfgang %A Stolte, Andrea %D 2014 %K formation massive star %T The Discovery of a Very Massive Star in W49 %U http://arxiv.org/abs/1407.4804 %X Very massive stars (M>100 M$_ødot$) are very rare objects, but have a strong influence on their environment. The formation of this kind of objects is of prime importance in star formation, but observationally still poorly constrained. We report on the identification of a very massive star in the central cluster of the star-forming region W49. We investigate near-infrared K-band spectroscopic observations of W49 from VLT/ISAAC together with JHK images obtained with NTT/SOFI and LBT/LUCI. We derive a spectral type of W49nr1, the brightest star in the dense core of the central cluster of W49. On the basis of its K-band spectrum, W49nr1 is classified as an O2-3.5If* star with a K-band absolute magnitude of -6.27$\pm$0.10 mag. The effective temperature and bolometric correction are estimated from stars of similar spectral type. After comparison to the Geneva evolutionary models, we find an initial mass between 100 M$_ødot$ and 180 M$_ødot$. Varying the extinction law results in a larger initial mass range of 90 - 250 M$_ødot$.

@misc{wu2014discovery, abstract = {Very massive stars (M>100 M$_{\odot}$) are very rare objects, but have a strong influence on their environment. The formation of this kind of objects is of prime importance in star formation, but observationally still poorly constrained. We report on the identification of a very massive star in the central cluster of the star-forming region W49. We investigate near-infrared K-band spectroscopic observations of W49 from VLT/ISAAC together with JHK images obtained with NTT/SOFI and LBT/LUCI. We derive a spectral type of W49nr1, the brightest star in the dense core of the central cluster of W49. On the basis of its K-band spectrum, W49nr1 is classified as an O2-3.5If* star with a K-band absolute magnitude of -6.27$\pm$0.10 mag. The effective temperature and bolometric correction are estimated from stars of similar spectral type. After comparison to the Geneva evolutionary models, we find an initial mass between 100 M$_{\odot}$ and 180 M$_{\odot}$. Varying the extinction law results in a larger initial mass range of 90 - 250 M$_{\odot}$.}, added-at = {2014-07-21T09:28:39.000+0200}, author = {Wu, Shi-Wei and Bik, Arjan and Henning, Thomas and Pasquali, Anna and Brandner, Wolfgang and Stolte, Andrea}, biburl = {https://www.bibsonomy.org/bibtex/2d7965f327a771fd2c27897900dbb89ee/miki}, description = {[1407.4804] The Discovery of a Very Massive Star in W49}, interhash = {15b8e3f2d3932ee4e403486619b037d9}, intrahash = {d7965f327a771fd2c27897900dbb89ee}, keywords = {formation massive star}, note = {cite arxiv:1407.4804Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&A Letters}, timestamp = {2014-07-21T09:28:39.000+0200}, title = {The Discovery of a Very Massive Star in W49}, url = {http://arxiv.org/abs/1407.4804}, year = 2014 }