J/A+A/466/L1 VLTI observations of RY Sgr (Leao+, 2007)
A snapshot of the inner dusty regions of a R CrB-type variable.
Leao I., de Laverny P., Chesneau O., Mekarnia D., De Medeiros J.R.
<Astron. Astrophys. 466, L1 (2007)>
=2007A&A...466L...1L 2007A&A...466L...1L (SIMBAD/NED BibCode)
ADC_Keywords: Interferometry ; Stars, variable
Keywords: stars: AGB and post-AGB - stars: variables: general -
stars: individual: RY Sgr - stars: mass-loss -
stars: circumstellar matter - techniques: interferometric
Description:
We present high spatial resolution observations in the mid-infrared of
the R CrB star RY Sgr obtained with the Very Large Telescope
Interferometer (VLTI) of ESO's Paranal Observatory and MIDI, the
MID-infrared Interferometric recombiner. MIDI combines the light of
two telescopes and provides spectrally resolved visibilities in the N
band atmospheric window. The observations of RY Sgr were conducted
with the VLT Unit Telescopes (UTs) UT1, UT3 and UT4, providing
projected baselines in the range of 57-129 meters oriented from
PA=34° to 135°. The UTs observations were made during the
nights of May 25-26th 2005, June 24-25th 2005, June 25-26th 2005 and
June 27-28th 2005. All the observations were made under rather good
atmospheric conditions. The files include all visibility data recorded
from these observations as well as all the characteristics concerning
the observations. The log of the observations is shown in Table 1 of
the paper (table1.dat).
Objects:
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RA (2000) DE Designation(s)
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19 16 32.8 -33 31 20 RY Sgr = HD 180093
19 06 56.4 -27 40 14 HD 177716 = HIP 93864
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 54 14 Journal of the VLTI/MIDI observations of RY Sgr
fig/* . 7 *FITS files of baseline observations
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Note on fig/*:
All the data products are stored in the FITS-based, optical
interferometry data exchange format (OI-FITS), described in Pauls et
al. (2005PASP..117.1255P 2005PASP..117.1255P). The OI Exchange Format is a standard for
exchanging calibrated data from optical (visible/infrared) stellar
interferometers. The standard is based on the Flexible Image Transport
System (FITS), and supports storage of the optical interferometric
observables including visibilities and differential phases. Several
routines to read and write this format in various languages can be
found in:
http://www.mrao.cam.ac.uk/~jsy1001/exchange/
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See also:
J/A+A/353/287 : The R CrB stars (Asplund+, 2000)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star name
12- 21 A10 "YYYY-MM-DD" Obs.Date UT observation date
23- 27 A5 --- Obs.Time Observation time (hh:mm)
29- 31 I3 m Base ?=- Base
33- 35 I3 deg PA ?=- Position angle
37- 54 A18 --- FileName Corresponding fits file in
"fig" subdirectory
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Acknowledgements:
Patrick de Laverny, laverny(at)oca.eu
Walter Jaffe, Rainer Koehler, John Monnier and Armando Domiciano
(End) Patricia Vannier [CDS] 17-Mar-2007