Related papers: Anti-solar differential rotation and surface flow …
We have searched for discrete refractive scattering events (including effects due to possible non-multiple diffractive scattering) at meter wavelengths in the direction of two close by pulsars B0950+08 and B1929+10, where we looked for…
We determine here peculiar motion of the Solar system, first time from the $m-z$ Hubble diagram of quasars. Observer's peculiar motion causes a systematic shift in the $m-z$ plane between sources lying along the velocity vector and those in…
We model the temperature distribution at the surface of a magnetized neutron star and study the effects on the observable X-ray spectra and light curves, taking fully into account gravitational lensing. Only dipolar fields are considered…
Over time, tides synchronize the rotation periods of stars in a binary system to the orbital period. However, if the star exhibits differential rotation then only a portion of it can rotate at the orbital period, so the rotation period at…
We explore the general properties of near-surface flows around solar active regions. Helioseismic holography is applied to HMI Dopplergrams yielding nearly 5000 flow measurements of 336 unique active regions observed by the Solar Dynamics…
We study solar differential rotation (DR) for solar cycle No. 19 (1954-1964) by tracing sunspot groups on the sunspot drawings of Kanzelhoehe Observatory for Solar and Environmental Research (KSO). Our aim is to extend previous DR analysis…
The (Zeeman-)Doppler imaging studies of solar-type stars very often reveal large high-latitude spots. This also includes F stars that possess relatively shallow convection zones, indicating that the dynamo operating in these stars differs…
We report on the results of four convective dynamo simulations with an outer coronal layer. The magnetic field is self-consistently generated by the convective motions beneath the surface. Above the convection zone, we include a polytropic…
This work investigates the weakly nonlinear dynamics of internal shear layers and the mean zonal flow induced by the longitudinal libration of an inner core within a spherical shell. Building on the work of He et al. (J. Fluid Mech., vol.…
We report on the variation in the optical polarization of the blazar PKS 1749+096 observed in 2008--2015. The degree of polarization (PD) tends to increase in short flares having a time-scale of a few days. The object favors a polarization…
High-quality time series provided by space instrumentation such as CoRoT and Kepler, allow us to measure modulations in the light curves due to changes in the surface of stars related to rotation and activity. Therefore, we are able to…
Four spatially resolved near-UV raster scans across the chromospheric disk of alpha Ori, obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, reveal mean chromospheric infall from 1998 January to 1998 April,…
With the plethora of detailed results from heliospheric missions and at the advent of the first mission dedicated IBEX, we have entered the era of precision heliospheric studies. Interpretation of these data require precision modeling, with…
We report near-infrared polarization of the zodiacal light (ZL) measured from space by the Diffuse Infrared Background Experiment (DIRBE) on board the Cosmic Background Explorer in photometric bands centered at 1.25, 2.2, and 3.5 $\mu$m. To…
We have discovered a class of eccentric binary systems within the Kepler data archive that have dynamic tidal distortions and tidally-induced pulsations. Each has a uniquely shaped light curve that is characterized by periodic brightening…
We model the surface magnetic field and open flux of the Sun from 1913 to 1986 using a surface flux transport model, which includes the observed cycle-to-cycle variation of sunspot group tilts. The model reproduces the empirically derived…
Solar convection is visible as a net blueshift of absorption lines, which becomes apparent when observing quiet Sun granulation. This blueshift exhibits variations from the disc centre to the solar limb due to differing projection angles…
X-ray spectra of the late-type star AB Dor, obtained with the XMM-Newton satellite are analysed. AB Dor was particularly active during the observations. An emission measure reconstruction technique is employed to analyse flare and quiescent…
We present the dynamics of two filaments and a C-class flare observed in NOAA 11589 on 2012 October 16. We used the multi-wavelength high-resolution data from SDO, as well as THEMIS and ARIES ground-based observations. The observations show…
We report detection of differential rotation on the F5 dwarf psi Cap using line profile analysis. The Fourier transform of both FeI lambda 5775 and SiI lambda 5772 are used to obtain a projected rotational velocity of v sini = (42+-1)km/s.…