Related papers: Anti-solar differential rotation and surface flow …
On the Sun, the rotation periods of individual sunspots not only trace the latitude dependence of the surface rotation rate, but also provide clues as to the amount of subsurface fluid shear. In this paper we present the first measurements…
The study of the differential rotation in the chromosphere of the Sun is of significant importance as it provides valuable insights into the rotational behaviour of the solar atmosphere at higher altitudes and the coupling mechanism between…
For solar activity cycles 20 and 21 (1966-1985) the solar differential rotation has been investigated using H{\alpha} filaments and relatively small-scale long-lived magnetic features with negative and positive polarities. We used annual…
On the AGB, low to intermediate mass stars blow away their outer envelopes, forming planetary nebulae. Interaction between the planetary nebula and its central progenitor is poorly understood and even more complex when the central object is…
Context. The relation between solar surface rotation and sunspot activity still remains open. Sunspot activity has dramatically reduced in solar cycle 24 and several solar activity indices and flux measurements experienced unprecedentedly…
Recently Gizon, Duvall and Schou (2002) suggested that supergranulation has a wave-like component. In this paper I show that the same phenomenon can be observed using surface Doppler shift data, thereby confirming their observations. I am…
The spectroscopic variability of Arcturus hints at cyclic activity cycle and differential rotation. This could provide a test of current theoretical models of solar and stellar dynamos. To examine the applicability of current models of the…
In this work, we use different methods to extract the surface rotation rate of Kepler targets showing solar-like oscillations.
Although the differential rotation rate on the solar surface has long been studied using optical and extreme ultraviolet (EUV) observations, associating these measurements to specific atmospheric heights remains challenging due to the…
Context: Stars with about 1$-$2 solar masses at the red giant branch (RGB) represent an intriguing period of stellar evolution, i.e. when the convective envelope interacts with the fast-rotating core. During these mixing episodes freshly…
Using 2D models of rotating stars, the interferometric measurements of alpha Eri and its fundamental parameters corrected for gravitational darkening effects we infer that the star might have a core rotating 2.7 times faster than the…
Using the wealth of ~24 yr multiband data, we present an in-depth study of the star-spot cycles, surface differential rotations (SDR), optical flares, evolution of star-spot distributions, and coronal activities on the surface of young,…
We present surface spot maps of the K2V primary star in the pre-cataclysmic variable binary system, V471 Tau. The spot maps show the presence of large high latitude spots located at the sub-white dwarf longitude region. By tracking the…
In the present work, we perform time-series analysis on the latitude bins of the solar full disk (SFD) images of Nobeyama Radioheliograph (NoRH) at 17 GHz. The flux modulation method traces the passage of radio features over the solar disc…
Understanding the global rotational profile of the solar atmosphere and its variation is fundamental to uncovering a comprehensive understanding of the dynamics of the solar magnetic field and the extent of coupling between different layers…
Asynchronous rotation in binary stars produces non-radial oscillations that are known to cause observable variability on orbital timescales. The horizontal perturbations of the surface velocity fields are referred to as "tidal flows". In…
We report new, extremely precise, photopolarimetry of the rapidly-rotating A0 main-sequence star $\zeta$ Aql, covering the wavelength range $\sim$400--900nm, which reveals a rotationally-induced signal. We model the polarimetry, together…
Context. We compare solar differential rotation of subphotospheric layers derived from local helioseismology analysis of GONG++ dopplergrams and the one derived from tracing small bright coronal structures (SBCS) using EIT/SOHO images for…
We measure differential rotation and meridional flow in the Sun's surface shear layer by tracking the motions of the magnetic network seen in magnetograms from SOHO/MDI and SDO/HMI over solar cycles 23, 24, and the start of 25 (1996-2022).…
Recently, we have developed a method useful for mapping large-scale horizontal velocity fields in the solar photosphere. The method was developed, tuned and calibrated using the synthetic data. Now, we applied the method to the series of…