Photometric and spectroscopic analysis of LBV candidate J004341.84+411112.0 in M31. (arXiv:2111.09148v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Sarkisyan_A/0/1/0/all/0/1">A. Sarkisyan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sholukhova_O/0/1/0/all/0/1">O. Sholukhova</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fabrika_S/0/1/0/all/0/1">S. Fabrika</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Valeev_A/0/1/0/all/0/1">A. Valeev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Valcheva_A/0/1/0/all/0/1">A. Valcheva</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nedialkov_P/0/1/0/all/0/1">P. Nedialkov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tatarnikov_A/0/1/0/all/0/1">A. Tatarnikov</a>

We study Luminous Blue Variable (LBV) candidate J004341.84+411112.0 in the
Andromeda galaxy. We present optical spectra of the object obtained with the
6-m telescope of SAO RAS. The candidate shows typical LBV features in its
spectra: broad and strong hydrogen lines and the He I lines with P Cigni
profiles. Its remarkable spectral resemblance to the well known LBV P Cygni
suggests a common nature of the objects and supports LBV classification of
J004341.84+411112.0. We estimate the temperature, reddening, radius and
luminosity of the star using its spectral energy distribution. Obtained
bolometric luminosity of the candidate ($M_{text{bol}}=-10.41pm0.12$ mag) is
quite similar to those of known LBV stars in the Andromeda galaxy. We analysed
ten year light curve of the object in $R$ filter. The candidate demonstrates
photometric variations of the order of 0.4 mag, with an overall brightness
increasing trend $Delta R > 0.1$ mag. Therewith, the corresponding colour
variations of the object are fully consistent with LBV behavior when a star
become cooler and brighter in the optical spectral range with a nearly constant
bolometric luminosity. LBV-type variability of the object, similarity of its
spectrum and estimated luminosity to those of known LBVs allows us to classify
J004341.84+411112.0 as a LBV.

We study Luminous Blue Variable (LBV) candidate J004341.84+411112.0 in the
Andromeda galaxy. We present optical spectra of the object obtained with the
6-m telescope of SAO RAS. The candidate shows typical LBV features in its
spectra: broad and strong hydrogen lines and the He I lines with P Cigni
profiles. Its remarkable spectral resemblance to the well known LBV P Cygni
suggests a common nature of the objects and supports LBV classification of
J004341.84+411112.0. We estimate the temperature, reddening, radius and
luminosity of the star using its spectral energy distribution. Obtained
bolometric luminosity of the candidate ($M_{text{bol}}=-10.41pm0.12$ mag) is
quite similar to those of known LBV stars in the Andromeda galaxy. We analysed
ten year light curve of the object in $R$ filter. The candidate demonstrates
photometric variations of the order of 0.4 mag, with an overall brightness
increasing trend $Delta R > 0.1$ mag. Therewith, the corresponding colour
variations of the object are fully consistent with LBV behavior when a star
become cooler and brighter in the optical spectral range with a nearly constant
bolometric luminosity. LBV-type variability of the object, similarity of its
spectrum and estimated luminosity to those of known LBVs allows us to classify
J004341.84+411112.0 as a LBV.

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