On the nature of the fast moving star S2 in the Galactic Center

Abstract

We analyze the properties of the star S2 orbiting the supermassive black hole at the center of the Galaxy. A high quality SINFONI H and K band spectrum obtained from coadding 23.5 hours of observation between 2004 and 2007 reveals that S2 is an early B dwarf (B0-2.5V). Using model atmospheres, we constrain its stellar and wind properties. We show that S2 is a genuine massive star, and not the core of a stripped giant star as sometimes speculated to resolve the problem of star formation so close to the supermassive black hole. We give an upper limit on its mass loss rate, and show that it is He enriched, possibly because of the presence of a magnetic field.

arXiv comment4 pages, 5 figures, ApJ letters accepted

References in corpus (19)

• The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• SINFONI in the Galactic Center: young stars and IR flares in the central light month
• The Stellar Cusp Around the Supermassive Black Hole in the Galactic Center
• Stellar disk in the galactic center -- a remnant of a dense accretion disk?
• SINFONI - Integral Field Spectroscopy at 50 milli-arcsecond resolution with the ESO VLT
• A Geometric Determination of the Distance to the Galactic Center
• Quantitative Spectroscopy of O Stars at Low Metallicity. O Dwarfs in NGC 346
• The structure of the nuclear stellar cluster of the Milky Way
• The VLT-FLAMES survey of massive stars: Evolution of surface N abundances and effective temperature scales in the Galaxy and Magellanic Clouds
• Stellar and wind properties of massive stars in the central parsec of the Galaxy
• A Medium Resolution Near-Infrared Spectral Atlas of O and Early B Stars
• Nucleosynthesis of light elements inside thermally pulsing AGB stars I: the case of intermediate-mass stars
• Stellar evolution with rotation and magnetic fields:III: The interplay of circulation and dynamo
• The VLT-FLAMES Survey of Massive Stars: Stellar parameters and rotational velocities in NGC3293, NGC4755 and NGC6611
• Quantitative H and K band spectroscopy of Galactic OB-stars at medium resolution
• Direct Feeding of the Black Hole at the Galactic Center with Radial Gas Streams from Close-In Stellar Winds
• The stars of the galactic center
• Young stars in the Galactic Centre: a potential intermediate-mass star origin

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• The Properties and Fate of the Galactic Center G2 Cloud
• Galactic-center S-Stars as a prospective test of the Einstein Equivalence Principle
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• Modelling Accretion Disk and Stellar Wind Interactions: the Case of Sgr A*
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