ﻻ يوجد ملخص باللغة العربية
In this paper we study periodic variability of the magnetic field in the Ap star 33 Lib. We found that its most probable period equals 83.5 years. There exist also possible shorter periods: 11.036 days, 7.649 days and 4.690 days. Analysis of the magnetic behavior of 33 Lib allows us to conclude, that the star shows the second longest period the slow rotator gamma Equ, the latter star with the period of 97 years.
We determined rotational period of practically nonrotating Ap star gamma Equ and claim $P_{rm rot}= 97$ years. This period is about 35000 times larger than the average rotational period among stars of the same spectral class. Paper discusses possible
We investigated magnetic variability of the roAp star gamma Equ (HD 201601) with high time resolution. Measurements of the stellar longitudinal magnetic field B_e were performed with the hydrogen line polarimeter and the 6-m optical telescope of Spec
A growing number of Be and Oe stars, named the gamma Cas stars, are known for their unusually hard and intense X-ray emission. This emission could either trace accretion by a compact companion or magnetic interaction between the star and its decretio
Aims. Despite photometry and spectroscopy of its oscillations obtained over the past 25 years, the pulsation frequency spectrum of the rapidly oscillating Ap (roAp) star gamma Equ has remained poorly understood. Better time-series photometry, combine
We report the discovery of two massive eccentric systems with BRITE data, $tau$ Ori and $tau$ Lib, showing heartbeat effects close to the periastron passage. $tau$ Lib exhibits shallow eclipses that will soon vanish due to the apsidal motion in the s