J/A+A/544/A91 ε Aur visibility measurements (Mourard+, 2012)
A high angular and spectral resolution view into the hidden companion of
epsilon Aurigae.
Mourard D., Harmanec P., Stencel R., Berio P., Chesneau O., Clausse J.M.,
Ligi R., Nardetto N., Perraut K., Stee P., Tallon-Bosc I., McAlister H.,
ten Brummelaar T., Ridgway S., Sturmann J., Sturmann L., Turner N.,
Farrington C., Goldfinger P.J.
<Astron. Astrophys. 544, A91 (2012)>
=2012A&A...544A..91M 2012A&A...544A..91M
ADC_Keywords: Binaries, eclipsing
Keywords: stars: individual: epsilon Aurigae - star: binaries: eclipsing -
stars: AGB/post-AGB - stars: massive and circumstellar matter
Abstract:
The enigmatic binary, epsilon Aurigae, is yielding its parameters as a
result of new methods applied to the recent eclipse, including optical
spectro-interferometry with the VEGA beam combiner at the CHARA Array.
VEGA/CHARA visibility measurements from 2009 to 2011 indicate the
formation of emission wings of Halpha in an expanding zone almost
twice the photospheric size of the F star, namely, in a stellar wind.
These may be caused by shocks in the atmosphere from large scale
convective or multi-periodic pulsation modes emerging from the star.
During the total eclipse phase in 2010, when the disk was in the line
of sight, we saw broadening of the Halpha absorption and a less steep
drop of the visibility curve, consistent with the addition of neutral
hydrogen in the line of sight but extended above and below the plane
of the interferometrically imaged disk itself. This provides a unique
constraint on the scale height of the gaseous component of the disk
material, and, based on some additional assumptions, points to a mass
of the central object being 2.4 to 5.5M☉ for a distance of 650pc
or 3.8 to 9.1M☉ for a distance of 1050pc. These results can be
tested during coming observing seasons as the star moves from eclipse
phase toward quadrature.
Description:
VEGA/CHARA interferometric observations in differential mode are
provided in the attached files, according to the OIFITS format.
Objects:
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RA (2000) DE Designation(s)
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05 01 58.13 +43 49 23.9 epsilon Aur = V* eps Aur
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 54 63 *List of OIFITS files
fits/* . 63 OIFITS files
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Note on list.dat: The OIFITS files contains the normalized differential
visibility in the OI_VIS/VISAMP and OI_VIS/VISPHI tables. The wavelength is
given in OIWAVELENGTH/EFFWAVE table.
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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- 8 A8 --- Line Line observed (Hα, KI, NaD, SiII)
15- 24 A10 "YYYY/MM/DD" Obs.date Observation date
26- 30 A5 "h:m" Obs.time Observation time
32- 54 A23 --- FileName Name of the OIFITS file in subdirectory fits
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Acknowledgements:
Denis Mourard, denis.mourard(at)oca.eu
History:
* 19-Jul-2012: Original version
* 12-Oct-2014: The set of 63 OIFITS files (in "fits" subdirectory)
have been fixed by the author (Denis Mourard) -- the original
FITS files were not fully compatible with the OIFITS standard.
(End) Patricia Vannier [CDS] 19-Jul-2012