TY  - JOUR
A1  - Schoeller, M.
A1  - Hubrig, Swetlana
A1  - Ilyin, Ilya
A1  - Kharchenko, N. V.
A1  - Briquet, Maryline
A1  - Gonzalez, J. F.
A1  - Langer, Norbert
A1  - Oskinova, Lida
T1  - Magnetic field studies of massive main sequence stars
JF  - Astronomische Nachrichten = Astronomical notes
N2  - We report on the status of our spectropolarimetric observations of massive stars. During the last years, we have discovered magnetic fields in many objects of the upper main sequence, including Be stars, beta Cephei and Slowly Pulsating B stars, and a dozen O stars. Since the effects of those magnetic fields have been found to be substantial by recent models, we are looking into their impact on stellar rotation, pulsation, stellar winds, and chemical abundances. Accurate studies of the age, environment, and kinematic characteristics of the magnetic stars are also promising to give us new insight into the origin of the magnetic fields. Furthermore, longer time series of magnetic field measurements allow us to observe the temporal variability of the magnetic field and to deduce the stellar rotation period and the magnetic field geometry. Studies of the magnetic field in massive stars are indispensable to understand the conditions controlling the presence of those fields and their implications on the stellar physical parameters and evolution.
KW  - stars: early-type
KW  - stars: magnetic fields
KW  - stars: kinematics
KW  - techniques: polarimetric
Y1  - 2011
U6  - https://doi.org/10.1002/asna.201111606
SN  - 0004-6337
VL  - 332
IS  - 9-10
SP  - 994
EP  - 997
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Kholtygin, A. F.
A1  - Fabrika, S. N.
A1  - Rusomarov, N.
A1  - Hamann, Wolf-Rainer
A1  - Kudryavtsev, D. O.
A1  - Oskinova, Lida
A1  - Chountonov, G. A.
T1  - Line profile variability and magnetic fields of Wolf-Rayet stars: WR 135
 and WR 136
JF  - ASTRONOMISCHE NACHRICHTEN
N2  - We have obtained spectropolarimetric observations of two Wolf-Rayet stars, WR 135 (WC8) and WR 136 (WN6), with the 6-m Russian telescope in July 2009 and July 2010. We have studied the He II 5412 angstrom line region, which contains also the C IV 5469 angstrom line (for WR 135 only). Our goals were to investigate the rapid line-profile variability (LPV) in WR star spectra and to search for magnetic fields. We find small amplitude emission peaks moving from the center of He II line to its wings during the night in spectra of both stars. These emission peaks are likely a signature of accelerating clumps in the stellar wind. We obtained upper limits of the magnetic field strength: approximate to 200G for WR 135 and approximate to 50G for WR 136. (C) 2011 WILEY-VCH Verlag GmbH&Co. KGaA, Weinheim
KW  - stars: atmospheres
KW  - stars: magnetic fields
KW  - stars: winds
KW  - stars: Wolf-Rayet
KW  - techniques: polarimetric
Y1  - 2011
U6  - https://doi.org/10.1002/asna.201111595
SN  - 0004-6337
VL  - 332
IS  - 9-10
SP  - 1008
EP  - 1011
PB  - WILEY-BLACKWELL
CY  - MALDEN
ER  -