Spectroscopic and Photometric Study of the New Eclipsing Polar Gaia23cer

Abstract

We present the results of our optical study of the eclipsing polar Gaia23cer. We analyze the orbital brightness variability in high (\(\langle r\rangle\approx 16.5^{m}\)) and low (\(\langle r\rangle\approx 19.2^{m}\)) states. The system has an orbital period \(P_{\textrm{orb}}=102.0665\pm 0.0015\) min and exhibits deep eclipses with a duration \(\Delta t_{\textrm{ecl}}=401.30\pm 0.81\) s. The spectra have a red cyclotron continuum with the Zeeman H\(\alpha\) absorption triplet forming in a magnetic field with a strength \(B=15.2\pm 1.1\) MG. The source of emission lines has a high radial velocity semi-amplitude (\(K\approx 450\) km s\({}^{-1}\)), and its eclipse lags behind the eclipse of the white dwarf. The mass \(M_{1}=0.79\pm 0.03\;M_{\odot}\) and temperature \(T=11\,350\pm 650\) K of the white dwarf have been estimated by modelling the spectral energy distribution. The eclipse duration corresponds to a donor mass \(M_{2}=0.10{-}0.13\;M_{\odot}\) and an orbital inclination \(i=84.3^{\circ}{-}87.0^{\circ}\). The donor temperature was estimated to be \(T\approx 2900\) K by modelling the elliptical variability and eclipse depth.