J/MNRAS/426/2208 Hα variations of O9 subgiant HD57682 (Grunhut+, 2012)
Investigating the spectroscopic, magnetic and circumstellar variability of the
O9 subgiant star HD57682.
Grunhut J.H., Wade G.A., Sundqvist J.O., Ud-Doula A., Neiner C., Ignace R.,
Marcolino W.L.F., Rivinius T., Fullerton A., Kaper L., Mauclaire B.,
Buil C., Garrel T., Ribeiro J., Ubaud S.
<Mon. Not. R. Astron. Soc., 426, 2208-2227 (2012)>
=2012MNRAS.426.2208G 2012MNRAS.426.2208G
ADC_Keywords: Stars, O ; Magnetic fields ; Equivalent widths
Keywords: techniques: polarimetric - circumstellar matter -
stars: individual: HD 57682 - stars: magnetic field -
stars: rotation - stars: winds, outflows
Abstract:
The O9IV star HD 57682, discovered to be magnetic within the context
of the Magnetism in Massive Stars (MiMeS) survey in 2009, is one of
only eight convincingly detected magnetic O-type stars. Among this
select group, it stands out due to its sharp-lined photospheric
spectrum. Since its discovery, the MiMeS Collaboration has continued
to obtain spectroscopic and magnetic observations in order to refine
our knowledge of its magnetic field strength and geometry, rotational
period and spectral properties and variability. In this paper we
report new Echelle SpectroPolarimetric Device for the Observation of
Stars (ESPaDOnS) spectropolarimetric observations of HD 57682, which
are combined with previously published ESPaDOnS data and archival
Hα spectroscopy. This data set is used to determine the
rotational period (63.5708±0.0057d), refine the longitudinal
magnetic field variation and magnetic geometry (dipole surface field
strength of 880±50G and magnetic obliquity of 79±4° as
measured from the magnetic longitudinal field variations, assuming an
inclination of 60°) and examine the phase variation of various
lines.
Description:
A total of 38 polarimetric observations were collected with the
high-resolution (R∼68000) Echelle SpectroPolarimetric Device for the
Observation of Stars (ESPaDOnS) spectropolarimeter mounted on the
Canada-France-Hawaii Telescope (CFHT). The observations were obtained
in the context of the Magnetism in Massive Stars (MiMeS) CFHT Large
Programme on 20 different nights over a period of 2yr from 2008
December to 2010 December.
Objects:
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RA (2000) DE Designation(s)
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07 22 02.05 -08 58 45.8 HD 57682 = HR 2806
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 34 87 Hα equivalent widths measurements
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Inst Instrument or observatory name
10- 21 F12.4 d HJD [2450125/2455682] Heliocentric Julian date
23- 28 F6.3 0.1nm EWHa Measured Hα equivalent width (Å)
30- 34 F5.3 0.1nm e_EWHa rms uncertainty on EWHa (Å)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Apr-2013