J/A+A/568/L13 K-band spectrum of the very massive star W49nr1 (Wu+, 2014) ================================================================================ The discovery of a very massive star in W49. Wu S., Bik A., Henning T., Pasquali A., Brandner W., Stolte A. =2014A&A...568L..13W ================================================================================ ADC_Keywords: Clusters, open ; Stars, supergiant ; Photometry, infrared Keywords: stars: formation - stars: massive - stars: supergiants - infrared: stars - techniques: spectroscopic - open clusters and associations: individual: W49 Abstract: Very massive stars (M>100M_{sun}_) 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. Description: A medium-resolution (R=10,000) K-band spectrum of W49nr1 was obtained with ISAAC mounted on Antu (UT1) of ESO's Very Large Telescope (VLT), Paranal, Chile. J- and H-band images were obtained with SOFI at the New Technology Telescope (NTT), La Silla, Chile and a K- band image was acquired with LUCI mounted on the Large Binocular Telescope (LBT), Mount Graham, Arizona. Objects: ------------------------------------------- RA (2000) DE Designation(s) ------------------------------------------- 19 10 17.43 +09 06 20.93 W49nr1 ------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file list.dat 97 1 Information on spectrum file w49nr1Kb.fits 2880 15 Spectrum FITS file -------------------------------------------------------------------------------- Byte-by-byte Description of file: list.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 9 F9.5 deg RAdeg Right ascension (J2000) 10- 17 F8.5 deg DEdeg Declination (J2000) 19- 25 F7.1 0.1nm lam.min [20770.3] Lower value of wavelength interval 27- 33 F7.1 0.1nm lam.max [22026.5] Upper value of wavelength interval 35- 41 F7.5 0.1nm dlam [1.22796] Spectral resolution 43- 46 I4 --- Nx [1024] Number of measurements 48- 49 I2 Kibyte size [42] Size of FITS file 51- 64 F14.8 d MJD Observation date 66- 78 A13 --- FileName Name of the FITS file 80- 97 A18 --- Title Title of the file -------------------------------------------------------------------------------- Acknowledgements: Shiwei Wu, shiwei(at)mpia.de ================================================================================ (End) Patricia Vannier [CDS] 25-Jul-2014