J/A+A/566/A125 Rigel K-band temporal monitoring (Chesneau+, 2014)
The variable stellar wind of Rigel probed at high spatial and spectral
resolution.
Chesneau O., Kaufer A., Stahl O., Colvinter C., Spang A., Dessart L.,
Prinja R., Chini R.
<Astron. Astrophys. 566, A125 (2014)>
=2014A&A...566A.125C 2014A&A...566A.125C
ADC_Keywords: Stars, supergiant ; Interferometry
Keywords: techniques: high angular resolution - techniques: interferometric -
stars: mass-loss - stars: individual: Rigel - stars: rotation -
stars: circumstellar matter
Abstract:
Luminous BA-type supergiants are the brightest stars in the visible
that can be observed in distant galaxies and are potentially accurate
distance indicators. The impact of the variability of the stellar
winds on the distance determination remains poorly understood.
Our aim is to probe the inhomogeneous structures in the stellar wind
using spectro-interferometric monitoring.
We present a spatially resolved, high-spectral resolution (R=12000)
K-band temporal monitoring of the bright supergiant β Orionis
(Rigel, B8 Iab) using Amber at the Very Large Telescope Interferometer
(VLTI). Rigel was observed in the Brγ line and its nearby
continuum once per month over 3 months in 2006-2007, and 5 months in
2009-2010. These unprecedented observations were complemented by
contemporaneous optical high-resolution spectroscopy. We analyse the
near-IR spectra and visibilities with the 1D non-LTE
radiative-transfer code CMFGEN. The differential and closure phase
signals are evidence of asymmetries that are interpreted as
perturbations of the wind.
Description:
For the 2009-2010 campaign the Beso (Bochum Echelle Spectrograph for
OCA) spectrograph at the 1.5-m Hexapod-Telescope at the Observatario
Cerro Armazones (OCA), Chile, was used.
Objects:
---------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------
05 14 32.27 -08 12 05.9 Rigel = * bet Ori
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 65 79 List of BESO FITS spectra
sp/* . 79 Individual FITS spectra
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 um lam.0 Lower value of wavelength interval
9- 15 F7.2 um lam.1 Upper value of wavelength interval
17- 20 F4.2 um Dlam Wavelength resolution
23- 28 I6 --- Nx [177861/177896] Number of measurements
30- 32 I3 Kibyte size [709] Size of FITS file
34- 47 F14.8 d MJD [55110/55294] Observation date
49- 65 A17 --- FileName Name of the FITS file in subdirectory sp
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Acknowledgements:
Otmar Stahl, o.stahl(at)lsw.uni-heidelberg.de
(End) Patricia Vannier [CDS] 13-May-2014