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
mechanism explaining the origin of this phenomenon.
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 magn
etic 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.
The Stark-induced shift and asymmetry, the so-called pressure shift (PS) of $H_alpha$ and $H_beta$ Balmer lines in spectra of DA white dwarfs (WDs), as masking effects in measurements of the gravitational red shift in WDs, have been examined in detai
l. The results are compared with our earlier ones from before a quarter of a century (Grabowski et al. 1987, hereafter ApJ87; Madej and Grabowski 1990). In these earlier papers, as a dominant constituent of the Balmer-line-profiles, the standard, symmetrical Stark line profiles, shifted as the whole by PS-effect, were applied to all spectrally active layers of the WD atmosphere. At present, in each of the WD layers, the Stark-line-profiles (especially of $H_beta$) are immanently asymmetrical and shifted due to the effects of strong inhomogeneity of the perturbing fields in plasma. To calculate the Stark line-profiles in successive layers of the WD atmosphere we used the modified Full Computer Simulation Method (mFCSM), able to take adequately into account the complexity of local elementary quantum processes in plasma. In the case of the $H_alpha$ line, the present value of Stark-induced shift of the synthetic $H_alpha$ line-profile is about twice smaller than the previous one (ApJ87) and it is negligible in comparison with the gravitational red shift. In the case of the $H_beta$ line, the present value of Stark-induced shift of the synthetic $H_beta$ line-profile is about twice larger than the previous one. The source of this extra shift is the asymmetry of $H_beta$ peaks.
We re-analyzed SUZAKU data of the black hole candidate 4U 1630-472 being in the high/soft state. We show that the continuum X-ray spectrum of 4U 1630-472 with iron absorption lines can be satisfactorily modeled by the spectrum from an accretion disk
atmosphere. Absorption lines of highly ionized iron originating in hot accretion disk atmosphere can be an alternative or complementary explanation to the wind model usually favored for these type of sources. We model continuum and line spectra using a single model. Absorption lines of highly ionized iron can origin in upper parts of the disk atmosphere which is intrinsically hot due to high disk temperature. Iron line profiles computed with natural, thermal and pressure broadenings match very well observations. We showed that the accretion disk atmosphere can effectively produce iron absorption lines observed in 4U 1630-472 spectrum. Absorption line arising in accretion disk atmosphere is the important part of the observed line profile, even if there are also other mechanisms responsible for the absorption features. Nevertheless, the wind theory can be an artifact of the fitting procedure, when the continuum and lines are fitted as separate model components.
