A new look into putative duplicity and pulsations of the Be star $beta$ CMi. (arXiv:1902.07450v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Harmanec_P/0/1/0/all/0/1">P. Harmanec</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Svanda_M/0/1/0/all/0/1">M. Svanda</a> (1 and 2), <a href="http://arxiv.org/find/astro-ph/1/au:+Korcakova_D/0/1/0/all/0/1">D. Korcakova</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Chini_R/0/1/0/all/0/1">R. Chini</a> (3 and 4), <a href="http://arxiv.org/find/astro-ph/1/au:+Nasseri_A/0/1/0/all/0/1">A. Nasseri</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_S/0/1/0/all/0/1">S. Yang</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Bozic_H/0/1/0/all/0/1">H. Bozic</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Slechta_M/0/1/0/all/0/1">M. Slechta</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Vanzi_L/0/1/0/all/0/1">L. Vanzi</a> (7) ((1) Astronomical Institute of the Charles University (2) Astronomical Institute of the Czech Academy of Sciences (3) Astronomisches Institut, Ruhr-Universitat Bochum (4) Instituto de Astronomia, Universidad Catolica del Norte (5) Physics&Astronomy Department, University of Victoria (6) Hvar Observatory (7) Department of Electrical Engineering and Centre of Astro-Engineering, Pontificia Universidad Catolica de Chile)
Bright Be star beta CMi has been identified as a non-radial pulsator on the
basis of space photometry with the MOST satellite and also as a single-line
spectroscopic binary with a period of 170.4 d. The purpose of this study is to
re-examine both these findings, using numerous electronic spectra from the
Dominion Astrophysical Observatory, Ondv{r}ejov Observatory,
Universit”atssterwarte Bochum, archival electronic spectra from several
observatories, and also the original MOST satellite photometry. We measured the
radial velocity of the outer wings of the double Halpha emission in all spectra
at our disposal and were not able to confirm significant radial-velocity
changes. We also discuss the problems related to the detection of very small
radial-velocity changes and conclude that while it is still possible that the
star is a spectroscopic binary, there is currently no convincing proof of it
from the radial-velocity measurements. Wavelet analysis of the MOST photometry
shows that there is only one persistent (and perhaps slightly variable)
periodicity of 0.617 d of the light variations, with a double-wave light curve,
all other short periods having only transient character. Our suggestion that
this dominant period is the star’s rotational period agrees with the estimated
stellar radius, projected rotational velocity and with the orbital inclination
derived by two teams of investigators. New spectral observations obtained in
the whole-night series would be needed to find out whether some possibly real,
very small radial-velocity changes cannot in fact be due to rapid line-profile
changes.
Bright Be star beta CMi has been identified as a non-radial pulsator on the
basis of space photometry with the MOST satellite and also as a single-line
spectroscopic binary with a period of 170.4 d. The purpose of this study is to
re-examine both these findings, using numerous electronic spectra from the
Dominion Astrophysical Observatory, Ondv{r}ejov Observatory,
Universit”atssterwarte Bochum, archival electronic spectra from several
observatories, and also the original MOST satellite photometry. We measured the
radial velocity of the outer wings of the double Halpha emission in all spectra
at our disposal and were not able to confirm significant radial-velocity
changes. We also discuss the problems related to the detection of very small
radial-velocity changes and conclude that while it is still possible that the
star is a spectroscopic binary, there is currently no convincing proof of it
from the radial-velocity measurements. Wavelet analysis of the MOST photometry
shows that there is only one persistent (and perhaps slightly variable)
periodicity of 0.617 d of the light variations, with a double-wave light curve,
all other short periods having only transient character. Our suggestion that
this dominant period is the star’s rotational period agrees with the estimated
stellar radius, projected rotational velocity and with the orbital inclination
derived by two teams of investigators. New spectral observations obtained in
the whole-night series would be needed to find out whether some possibly real,
very small radial-velocity changes cannot in fact be due to rapid line-profile
changes.
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