相关论文: Surface temperature maps for II Peg during 1999-20…

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 The six maps from 1999-2002 are based on previously unpublished observations. Through Doppler imaging we want to study the spot…

Aims. We study the spot activity of II Peg during the years 2004-2010 to determine long- and short-term changes in the magnetic activity. In a previous study, we detected a persistent active longitude, as well as major changes in the spot…

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 number of cool stars magnetic field topologies were…

Data from 11 years of continuous spectroscopic observations of the active RS CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in three…

Magnetic fields of cool active stars are currently studied polarimetrically using only circular polarization observations. Including linear polarization in the reconstruction of stellar magnetic fields allows more information about the…

We present Doppler images of the young K5V - K7V rapid rotator LO Peg from seven nights of continuous spectroscopy obtained in 1998 from July 04 to July 10. The images reveal the presence of a strong polar cap with appendages extending to…

We present the results of a contemporaneous photometric and spectroscopic monitoring of lambda And and II Peg aimed at investigating the behavior of surface inhomogeneities in the atmospheres of these active stars which have nearly the same…

New spectral line polarisation observations of 7 bright Ap stars have been obtained with the ESPaDOnS and Narval high resolution spectropolarimeters (Silvester et al. 2012). The aim of this data set is produce a series of surface magnetic…

We present Zeeman-Doppler images of the active K2 star II Peg for the years 2004 and 2007. The surface magnetic field was reconstructed with our new ZDI code "iMap" which provides a full polarized radiative transfer driven inversion to…

We present here a continuation of our ongoing project of multiwavelength optical observations aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features that are…

In February 2003, March 2003 and January 2004 Pele plume transmission spectra were obtained during Jupiter transit with Hubble's Space Telescope Imaging Spectrograph (STIS), using the 0.1 arcsec long slit and the G230LB grating. The STIS…

We present a multiwavelength study of three chromospherically active stars, namely FR Cnc (= BD +16\degr 1753), HD 95559 and LO Peg (=BD +22\degr 4409), including newly obtained optical photometry, low-resolution optical spectroscopy for FR…

Measurements of the ionized Ca II K line are one of the major resources for long-term studies of solar and stellar activity. They also play a critical role in many studies related to solar irradiance variability, particularly as a…

We present here the results on the physical nature a RS CVn binary KIC 7885570 and its chromospheric activity based on the Kepler Mission data. Assuming the primary component temperature, 6530 K, the temperature of the secondary component…

The spectral position of the 3.6 micron continuum peak measured on Cassini-VIMS I/F spectra is used as a marker to infer the temperature of the regolith particles covering the surfaces of Saturn's icy satellites. This feature is…

Based on our photometric observations in 2015-2016 and archival photometric data for the active red giant PZ Mon, we have found the main characteristics of the stellar surface: the unspotted surface temperature Teff=4730K, the spot…

The large-scale magnetic field of solar-type stars reconstructed from their spectropolarimetric observations provide important insight into their underlying dynamo processes.We aim to investigate the temporal variability of the large-scale…

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 spot activity and compare to photometric data, specifically…

We present new UBV(RI)_C photometry of 22 stars that host transiting planets, 19 of which were discovered by the WASP survey. We use these data together with 2MASS JHK_S photometry to estimate the effective temperature of these stars using…

We have investigated the spectral behaviour of II Peg binary system in the ultraviolet band by using International Ultraviolet Explorer observations over fifteen years. The ultraviolet observations show indication of flare activity in the…