Related papers: Differential Rotation in F Stars
Newly born neutron stars can present differential rotation, even if later it should be suppressed by viscosity or a sufficiently strong magnetic field. And in this early stage of its life, a neutron star is expected to have a strong…
Cross-correlation of consecutive Doppler images is one of the most common techniques used to detect surface differential rotation (hereafter DR) on spotted stars. The disadvantage of a single cross-correlation is, however, that the expected…
Rotation is ubiquitous among massive stars. With rotation comes a deformation to the surface geometry, which in turn leads to alterations in the distribution of parameters across the surface including surface gravity, temperature and…
We examine the potential of asteroseismology for exploring the internal rotation of white dwarf stars. Data from global observing campaigns have revealed a wealth of frequencies, some of which show the signature of rotational splitting.…
Mechanisms influencing absorption line profiles of fast rotating stars can be sorted into two groups; (i) intrinsic variations sensitive to temperature and pressure, and (ii) global effects common to all spectral lines. I present a detailed…
Stellar differential rotation can be separated into two main regimes: solar-like when the equator rotates faster than the poles and anti-solar when the polar regions rotate faster than the equator. We investigate the transition between…
Rotation is a directly-observable stellar property, and drives magnetic field generation and activity through a magnetic dynamo. Main sequence stars with masses below approximately 0.35Msun (mid-to-late M dwarfs) are fully-convective, and…
We have examined the relationship between rotation and activity in 14 late-type (M6-M7) M dwarfs, using high resolution spectra taken at the W.M. Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most were…
Employing the Quark Mass Denisity- and temperature- dependent model and the Hartle's method, We have studied the slowly rotating strange star with uniform angular velocity. The mass-radius relation, the moment of inertia and the frame…
Radial differential rotation is an important parameter for stellar dynamo theory and for understanding angular momentum transport. We investigate the potential of using a large number of similar stars simultaneously to constrain their…
Phase resolved observations of planetary bodies allow us to understand the longitudinal and latitudinal variations that make each one unique. Rotational variations have been detected in several types of astronomical bodies beyond those of…
We have measured v sin i with high precision for a sample of dM3 stars (86 targets). We detected rotation in 82 stars (73 dM3 stars, and 9 dM3e stars). We compare our measurements of v sin i for all the stars in our dM0, dM2, dM3 and dM4…
Using precise measurements of the helium D3 line, we have searched for statistically significant variations in the strength of chromospheric activity in 13 early F-type stars and two late F-type stars. In two early F-type stars, we find…
Line ratios in "fir" triplets of helium-like ions have proven to be a powerful diagnostic of conditions in X-ray emitting gas surrounding massive stars. Recent observations indicate that these ratios can be variable with time. The possible…
V889 Herculis is one of the brightest single early-G type stars, a young Sun, that is rotating fast enough (P_rot =1.337 days) for mapping its surface by Doppler Imaging. The 10 FOCES spectra collected between 13-16 Aug 2006 at Calar Alto…
The characterization of solar surface differential rotation (SDR) from disk-integrated chromospheric measurements has important implications for the study of differential rotation and dynamo processes in other stars. Some chromospheric…
This study explores photometric variability in a sample of hot stars in order to test whether variability arises from rotational modulation due to surface temperature spots. Frequencies determined from the projected rotational velocities…
From high-precision MOST photometry spanning 35 days the existence of two spots rotating with slightly differing periods is confirmed. From the marginal probability distribution of the derived differential rotation parameter k its…
R-modes of neutron stars could be a source of gravitational waves for ground based detectors. If the precise frequency $\sigma$ is known, guided gravitational wave searches with enhanced detectability are possible. Because of its physical…
Asteroseismology has revealed that cores of red giants rotate about one order of magnitude faster than their convective envelopes. This paper attempts an explanation for this rotational state in terms of the theory of angular momentum…