J/A+A/545/A130 Interferometry of α Eri (Domiciano de Souza+, 2012)
Beyond the diffraction limit of optical/IR interferometers. I.
Angular diameter and rotation parameters of Achernar from differential phases.
Domiciano de Souza A., Hadjara M., Vakili F., Bendjoya P., Millour F.,
Abe L., Carciofi A.C., Faes D.M., Kervella P., Lagarde S., Marconi A.,
Monin J.-L., Niccolini G., Petrov R.G., Weigelt G.
<Astron. Astrophys. 545, A130 (2012)>
=2012A&A...545A.130D 2012A&A...545A.130D
ADC_Keywords: Stars, Be ; Interferometry
Keywords: stars: rotation - stars: individual: Achernar -
methods: observational - methods: numerical -
techniques: interferometric
Abstract:
Spectrally resolved long-baseline optical/IR interferometry of
rotating stars opens perspectives to investigate their fundamental
parameters and the physical mechanisms that govern their interior,
photosphere, and circumstellar envelope structures. Aims. Based on the
signatures of stellar rotation on observed interferometric
wavelength-differential phases, we aim to measure angular diameters,
rotation velocities, and orientation of stellar rotation axes.
Description:
We used the AMBER focal instrument at ESO-VLTI in its high spectral
resolution mode to record interferometric data on the fast rotator
Achernar. Differential phases centered on the hydrogen Brγ line
(K band) were obtained during four almost consecutive nights with a
continuous Earth-rotation synthesis during ∼5h/night, corresponding to
∼60° position angle coverage per baseline. These observations were
interpreted with our numerical code dedicated to long-baseline
interferometry of rotating stars.
Objects:
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RA (2000) DE Designation(s)
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01 37 42.85 -57 14 12.3 Achernar = * alf Eri
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 128 58 Log of the 28 VLTI/AMBER observations of Achernar
with details on the dates, times, and baseline
triplets. The calibration star is delta Phe
fits/* . 28 OI-FITS files for differential phases centered on
the hydrogen Brγ line (K band)
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Inst Observation AT triplet
10- 18 A9 --- Object Object (Achernar or delta Phe)
20- 35 A16 --- Date Date and time (YYYY-MM-DDThh:mm)
37- 38 I2 m Bproj1 Baseline length triplet
39 A1 --- --- [,]
41- 42 I2 m Bproj2 Baseline length triplet
43 A1 --- --- [,]
45- 47 I3 m Bproj3 Baseline length triplet
49- 52 I4 deg PA1 [-180/180] Baseline position angle triplet
53 A1 --- --- [,]
55- 58 I4 deg PA2 [-180/180] Baseline position angle triplet
59 A1 --- --- [,]
61- 64 I4 deg PA3 [-180/180] Baseline position angle triplet
66-128 A63 --- FileName Name of the OI-FITS file in subdirectory fits
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Acknowledgements:
Armando Domiciano de Souza, Armando.Domiciano(at)oca.eu
(End) Patricia Vannier [CDS] 06-Sep-2012