Related papers: 33 Lib - analog of gamma Equ
This paper presents a series of 95 new measurements of the longitudinal (effective) magnetic field $B_e$ of the Ap star $\gamma$ Equ (HD 201601). Observations were obtained at the coud\'e focus of the 1-m reflector at the Special…
We present an analysis of the secular variability of the longitudinal magnetic field B_e in the roAp star gamma Equ (HD 201601). Measurements of the stellar magnetic field B_e were mostly compiled from the literature, and append also our 33…
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…
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…
One of the most intriguing properties of the Ap (and Bp) stars is their slow rotation, compared to the superficially normal main-sequence stars in the same temperature range. In recent years, it has emerged that several percent of the Ap…
The ultraviolet stellar wind lines of the photometrically periodic variable early B-type star sigma Lupi were found to behave very similarly to what has been observed in known magnetic B stars, although no periodicity could be determined.…
The extraordinary magnetic Ap star HD75049 has been studied with data obtained with the ESO VLT and 2.2-m telescopes. Direct measurements reveal that the magnetic field modulus at maximum reaches 30kG. The star shows photometric, spectral…
$\xi^{1}$ CMa is a known magnetic star showing rotationally modulated magnetic variability with a period of 2.17937 d. However, recent work based on high-resolution spectropolarimetry suggests that the rotation period is longer than 30…
How magnetic fields contribute to the differentiation of the rotation rates of the Ap stars and affect the occurrence of non-radial pulsation in some of them are important open questions. Valuable insight can be gained into these questions…
We present the analysis of K2 short cadence data of the rapidly oscillating Ap (roAp) star, 33 Librae (HD 137949). The precision afforded to the K2 data allow us to identify at least 11 pulsation modes in this star, compared to the three…
We present an analysis of 210 high-resolution time-resolved spectropolarimetric observations of the roAp star gamma Equ obtained over three nights in August and September 2003. Radial velocity variations due to p-mode non-radial pulsations…
Context. The existence of a significant population of Ap stars with very long rotation periods (up to several hundred years) has progressively emerged over the past two decades. However, only lower limits of the periods are known for most…
In this paper, the period evolution of the rotating chemically peculiar star V473\,Tau (A0Si, V = 7.26 mag) is investigated. Even though the star has been observed for more than fifty years, for the first time four consecutive years of…
The rotation periods of Ap stars range over five to six orders of magnitude. The origin of their differentiation remains unknown. We carry out a systematic study of the longest period Ap stars to gain insight into their properties. We…
We present the first short time scale observations of the roAp star gamma Equ in linear polarized light obtained with the PEPSI polarimeter installed at the LBT. These observations are used to search for pulsation variability in Stokes Q…
In our search for new magnetic massive stars we use the strongest indirect indicator of a magnetic field in B stars, which is periodic variability of UV stellar wind lines occurring in a velocity range symmetric around zero. Our aim is to…
The majority of magnetic chemically peculiar (mCP) stars exhibit periodic light, magnetic, radio, and spectroscopic variations that can be adequately modelled as a rigidly-rotating main-sequence star with persistent surface structures.…
In this paper, the period evolution of the rotating chemically peculiar star V473\,Tau is investigated. Even though the star has been observed for more than fifty years, for the first time four consecutive years of space-based data covering…
The many peculiarities of Ap stars (not only chemical ones, but also magnetic field and slow rotation) may vary during the main-sequence evolution of these stars. We review here briefly the evidences found in the last thirty years for such…
The magnetic field in the O9.7 V star HD54879 has been monitored for almost a decade. Spectropolarimetric observations reveal a rather strong mean longitudinal magnetic field that varies with a period of about 7.41 yr. Observations in the…