Ultraviolet variability of the magnetic chemically peculiar star 56 Arietis

Abstract

The spectrophotometric variability of the magnetic chemically peculiar star 56 Arietis (56 Ari) in the far-ultraviolet spectral region from 1150 to 1980 Å is investigated. This study is based on the archival International Ultraviolet Explorer data obtained at different phases of the rotational cycle. The brightness of 56 Ari is not constant in the investigated wavelengths over the whole rotational period. The monochromatic light curves continuously change their shape with wavelength. The comparison of energy distributions at three phases shows that the first minimum of light curves at phase 0.25 is replaced by the maximum for λ > 1608 Å, but the second minimum of light curves at phase 0.65 is absent in the spectral region between λ1938 and λ1980 Å. Iron is responsible for the depression at λ1775 Å in the spectrum of 56 Ari.

Based on IUE Newly Extracted Spectra (INES) data from the IUE satellite.

E-mail: sokolov@gao.spb.ru