The Optical Study of the Eclipsing Polar SDSS J002637.06+242915.6

TL;DR

This study provides a detailed optical analysis of the eclipsing polar SDSS J002637.06+242915.6, revealing its magnetic field, accretion dynamics, and system parameters through phase-resolved spectroscopy and photometry.

Contribution

It offers new measurements of the magnetic field strength, accretion spot characteristics, and system geometry of the eclipsing polar SDSS J002637.06+242915.6.

Findings

Magnetic field strength of the white dwarf is approximately 15.1 MG.

The system's orbital inclination is between 77.2° and 80.6°.

The white dwarf mass is estimated between 0.42 and 0.72 solar masses.

Abstract

We have analyzed phase-resolved photometric and spectroscopic observations of the eclipsing polar SDSS J002637.06+242915.6. The light curve has a M-shaped bright phase that was reproduced using a simple model of an accreting magnetic white dwarf. The hydrogen emission lines exhibit a narrow component formed on the irradiated hemispere of the donor. The Doppler tomography revealed differences in the positions of emission regions of hydrogen and HeII $\lambda$4686 lines. The spectra exhibit a Zeeman absorption triplet of the H$\alpha$ line, formed in the cold halo around the accretion spot at a magnetic field strength of $B = 15.1 \pm 1.3$ MG. The spectra of the bright phase have a red cyclotron continuum, whose orbital variability has been interpreted within a simple model of an accretion spot. The modeling of the cyclotron continuum constrains the white dwarf's magnetic field to $B_{cyc} \lesssim 45$ MG. The analysis of the eclipse light curve and the radial velocities of the irradiated hemisphere yielded estimates for the orbital inclination $77.2^\circ \le i \le 80.6^\circ$, the mass ratio $0.23 \le q \le 0.43$, and the white dwarf mass $0.72 \ge M_1/M_\odot \ge 0.42$.