J/A+A/615/A131 R CMa radial velocity curves (Lehmann+, 2018)
Spectroscopic time-series analysis of R Canis Majoris.
Lehmann H., Tsymbal V., Pertermann A., Tkachenko A., Mkrtichian D.E.,
A-thano N.
<Astron. Astrophys. 615, A131 (2018)>
=2018A&A...615A.131L 2018A&A...615A.131L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Binaries, eclipsing ; Binaries, spectroscopic;
Radial velocities
Keywords: binaries: eclipsing - binaries: spectroscopic - stars: oscillations -
stars: variables: delta Scuti
Abstract:
R Canis Majoris is the prototype of a small group of Algol-type stars
showing short orbital periods and low mass ratios. A previous
detection of short-term oscillations in its light curve has not yet
been confirmed. We investigate a new time series of high-resolution
spectra with the aim to derive improved stellar and system parameters,
to search for the possible impact of a third component in the observed
spectra, to look for indications of activity in the Algol system, and
to search for short-term variations in radial velocities. We
disentangled the composite spectra into the spectra of the binary
components. Then we analysed the resulting high signal-to-noise
spectra of both stars. Using a newly developed program code based on
an improved method of least-squares deconvolution, we were able to
determine the radial velocities of both components also during primary
eclipse. This allowed us to develop a better model of the system
including the Rossiter-McLaughlin effect and to derive improved
orbital parameters. Combining the results with those from spectrum
analysis, we obtain accurate stellar and system parameters. We further
deduce at least one oscillation frequency of 21.38c/d. It could be
detected during primary eclipses only and confirms a previous
photometric finding. Results point to an amplitude amplification of
non-radial pulsation modes due to the eclipse mapping effect. The
presence of a HeI line in the spectra indicates mass transfer in the
R CMa system. Calculations of its Roche geometry give evidence that
the cool secondary component may fill its Roche lobe. No evidence of a
third body in the system could be found in the observed spectra.
Description:
A time series of radial velocities of the hot (RV1) and cool (RV2)
components of the eclipsing binary star R CMa is presented, derived
with the new least- squares-deconvolution code LSDbinary from a time
series of high-resolution spectra taken with the HERMES spectrograph
attached to the Mercator telescope at La Palma.
Objects:
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RA (2000) DE Designation(s)
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07 19 28.18 -16 23 42.9 R CMa = HD 57167
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 29 560 Radial velocities of R CMa
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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- 11 F11.7 --- BJD Barycentric Julian date (BJD-2457000)
13- 20 F8.3 km/s RV1 Radial velocity of the primary component (1)
22- 29 F8.3 km/s RV2 Radial velocity of the secondary component (1)
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Note (1): The primary is the brighter, hot component and the secondary component
is the cool companion in the Algol-type system.
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Acknowledgements:
Based on observations made with the Mercator Telescope, operated on
the island of La Palma by the Flemish Community, at the Spanish
Observatorio del Roque de los Muchachos of the Instituto de
Astrofisica de Canarias. The HERMES spectrograph is supported by the
Research Foundation - Flanders (FWO), Belgium; the Research Council of
KU Leuven, Belgium; the Fonds National de la Recherche Scientifique
(F.R.S.-FNRS), Belgium; the Royal Observatory of Belgium; the
Observatoire de Geneve, Switzerland; and the Thueringer
Landessternwarte Tautenburg, Germany.
Holger Lehmann, lehm(at)tls-tautenburg.de
(End) Holger Lehmann [TLS, Germany], Patricia Vannier [CDS] 18-Apr-2018