J/A+A/482/561 High spatial resolution observations of pi1 Gru (Sacuto+, 2008)
The close circumstellar environment of the semi-regular S-type star pi1 Gruis.
Sacuto S., Jorissen A., Cruzalebes P., Chesneau O., Ohnaka K.,
Quirrenbach A., Lopez B.
<Astron. Astrophys. 482, 561 (2008)>
=2008A&A...482..561S 2008A&A...482..561S
ADC_Keywords: Interferometry ; Stars, variable
Keywords: techniques: interferometric - techniques: high angular resolution -
stars: AGB and post-AGB - stars: circumstellar matter -
stars: mass-loss
Abstract:
We present high spatial resolution observations of the close
circumstellar environment of the semi-regular S-type star pi1 Gruis
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 pi1 Gruis were conducted with the VLT Auxiliary
Telescopes (ATs) A0, E0, D0 and G0, providing projected baselines in
the range of 15 to 64 meters oriented from PA=41 to 102°. The ATs
observations were made during the nights of May 21-23-24-25-27 2006,
June 19 2006, and August 08 2006. All the observations were made under
good atmospheric conditions (average seeing ∼0.94") with the worst
seeing (∼1.51") during the night of May 27 2006. The files includes
all visibility and differential phase data recorded from these
observations as well as all the characteristics concerning the
observations. The log of the observations is shown in Table 1.
Description:
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: Webpage
http://www.mrao.cam.ac.uk/research/OAS/oi_data/oifits.html
Objects:
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RA (2000) DE Designation(s)
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22 22 44.21 -45 56 52.6 pi1 Gru = HD 212087
22 42 40.05 -46 53 04.5 Beta Gru = HD 214952
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 50 14 Journal of the VLTI/MIDI observations of pi1 Gru
fig/* . 7 Spectrally-dispersed visibilities and differential
phases + detailed headers
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See also:
J/A+A/465/469 : High spatial resolution observations of HM Sge (Sacuto+, 2007)
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
11- 20 A10 "YYYY-MM-DD" Obs.Date Observation date
22- 29 A8 --- Obs.Time Observation time (hh:mm:ss)
31- 34 F4.1 m Base ?=- Base
36- 38 I3 deg PA ?=- Position angle
40- 50 A11 --- FileName Corresponding fits file, in subdirectory fig
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Acknowledgements: Stephane Sacuto, stephane.sacuto(at)univie.ac.at,
Walter Jaffe and Rainer Kohler
References:
Jaffe et al., 2004SPIE.5491..715J 2004SPIE.5491..715J
Pauls et al., 2005PASP..117.1255P 2005PASP..117.1255P
(End) Patricia Vannier [CDS] 04-Feb-2008