A Study of the Photometric Variability of the Peculiar Magnetic White Dwarf WD 1953-011

Valyavin, G.; Antonyuk, K.; Plachinda, S.; Clark, D. M.; Wade, G. A.; Fox Machado, Lester; Alvarez, M.; Lopez, J. M.; Hiriart, D.; Han, Inwoo; Jeon, Young-Beom; Bagnulo, S.; Zharikov, S. V.; Zurita, C.; Mujica, R.; Shulyak, D.; Burlakova, T.
Bibliographical reference

The Astrophysical Journal, Volume 734, Issue 1, article id. 17 (2011).

Advertised on:
6
2011
Number of authors
17
IAC number of authors
1
Citations
20
Refereed citations
16
Description
We present and interpret simultaneous new photometric and spectroscopic observations of the peculiar magnetic white dwarf WD 1953-011. The flux in the V-band filter and intensity of the Balmer spectral lines demonstrate variability with the rotation period of about 1.45 days. According to previous studies, this variability can be explained by the presence of a dark spot having a magnetic nature, analogous to a sunspot. Motivated by this idea, we examine possible physical relationships between the suggested dark spot and the strong-field magnetic structure (magnetic "spot" or "tube") recently identified on the surface of this star. Comparing the rotationally modulated flux with the variable spectral observables related to the magnetic "spot," we establish their correlation and therefore their physical relationship. Modeling the variable photometric flux assuming that it is associated with temperature variations in the stellar photosphere, we argue that the strong-field area and dark, low-temperature spot are comparable in size and located at the same latitudes, essentially overlapping each other with a possible slight longitudinal shift. In this paper, we also present a new, improved value of the star's rotational period and constrain the characteristics of the thermal inhomogeneity over the degenerate's surface.
Type