58 citations · 193 across the 7 of their papers we have counts for
7 papers
Starspot activity of HD 199178. Doppler images from 1994--2017
Thomas Hackman, Iya Ilyin, Jyri J. Lehtinen +4
Context. Studying the spots of late-type stars is crucial for distinguishing between the various proposed dynamo mechanisms believed to be the main cause of starspot activity. For…
Doppler Imaging of LQ Hya for 1998-2002
E. M. Cole, T. Hackman, M. J. Käpylä +3
We study the spot distribution on the surface of LQ~Hya during the observing seasons October 1998 -- November 2002. We look for persistent active longitudes, trends in the level of…
Magnetic field topology of the RS CVn star II Pegasi
O. Kochukhov, M. J. Mantere, T. Hackman +1
The dynamo processes in cool active stars generate complex magnetic fields responsible for prominent surface stellar activity and variability at different time scales. For a small…
Doppler images of the RS CVn binary II Pegasi during the years 1994-2002
Lindborg, M., Korpi +8
We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. The six maps from 1999-2002 are based on previously unpublished observation…
Magnetic Doppler imaging of the roAp star HD 24712
T. Lüftinger, O. Kochukhov, T. Ryabchikova +3
We present the first magnetic Doppler images of a rapidly oscillating Ap (roAp) star. We deduce information about magnetic field geometry and abundance distributions of a number of…
Pulsation in the atmosphere of the roAp star HD 24712. I. Spectroscopic observations and radial velocity measurements
T. Ryabchikova, M. Sachkov, W. W. Weiss +10
We have investigated the structure of the pulsating atmosphere of one of the best studied rapidly oscillating Ap stars, HD 24712. For this purpose we analyzed spectra collected dur…
Spectroscopy of roAp star pulsation: HD24712
M. Sachkov, T. Ryabchikova, S. Bagnulo +10
We present results of the radial velocity (RV) analysis of spectroscopic time-series observations of the roAp star HD24712 (HR1217) which were carried out simultaneously with the C…