448 citations · 3.8k across the 82 of their papers we have counts for
14 papers · 1 filter
Brightness, distribution, and evolution of sunspot umbral dots
T. L. Riethmueller, S. K. Solanki, V. Zakharov +1
We present a 106-minute TiO (705.7nm) time series of high spatial and temporal resolution that contains thousands of umbral dots (UDs) in a mature sunspot in the active region NOAA…
The intensity contrast of solar granulation: comparing Hinode SP results with MHD simulations
S. Danilovic, A. Gandorfer, A. Lagg +5
The contrast of granulation is an important quantity characterizing solar surface convection. We compare the intensity contrast at 630 nm, observed using the Spectro-Polarimeter (S…
A bright coronal downflow seen in multi-wavelength observations: evidence of a bifurcating flux-rope?
D. Tripathi, S. K. Solanki, H. E. Mason +1
Aims: To study the origin and characteristics of a bright coronal downflow seen after a coronal mass ejection associated with erupting prominences on 5 March 2000. Methods: This st…
First Stereoscopic Coronal Loop Reconstructions from Stereo Secchi Images
L. Feng, B. Inhester, S. K. Solanki +4
We present the first reconstruction of the three-dimensional shape of magnetic loops in an active region from two different vantage points based on simultaneously recorded images.…
Similarities and Differences between Coronal Holes and the Quiet Sun: Are Loop Statistics the Key?
T. Wiegelmann, S. K. Solanki
Coronal holes (CH) emit significantly less at coronal temperatures than quiet-Sun regions (QS), but can hardly be distinguished in most chromospheric and lower transition region li…
How to use magnetic field information for coronal loop identification?
T. Wiegelmann, B. Inhester, A. Lagg +1
The structure of the solar corona is dominated by the magnetic field because the magnetic pressure is about four orders of magnitude higher than the plasma pressure. Due to the hig…
The Nature of Running Penumbral Waves Revealed
D. Shaun Bloomfield, Andreas Lagg, Sami K. Solanki
We seek to clarify the nature of running penumbral (RP) waves: are they chromospheric trans-sunspot waves or a visual pattern of upward-propagating waves? Full Stokes spectropolari…
Grand minima and maxima of solar activity: New observational constraints
I. G. Usoskin, S. K. Solanki, G. A. Kovaltsov
Using a reconstruction of sunspot numbers stretching over multiple millennia, we analyze the statistics of the occurrence of grand minima and maxima and set new observational const…
ALMA as the ideal probe of the solar chromosphere
M. A. Loukitcheva, S. K. Solanki, S. White
The very nature of the solar chromosphere, its structuring and dynamics, remains far from being properly understood, in spite of intensive research. Here we point out the potential…
Properties of sunspots in cycle 23: I. Dependence of brightness on sunspot size and cycle phase
S. K. Mathew, V. Martinez Pillet, S. K. Solanki +1
In this paper we investigate the dependence of umbral core brightness, as well as the mean umbral and penumbral brightness on the phase of the solar cycle and on the size of the su…
The fraction of DA white dwarfs with kilo-Gauss magnetic fields
S. Jordan, R. Aznar Cuadrado, R. Napiwotzki +2
Weak magnetic field has been searched for on only a small number of white dwarfs. Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to previo…
The fraction of DA white dwarfs with kilo-Gauss magnetic fields
S. Jordan, R. Aznar Cuadrado, R. Napiwotzki +2
Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to our first high-precision circular-polarimetric study of 12 bright white dwarfs with the…
Spot Sizes on Sun-like Stars
S. K. Solanki, Y. C. Unruh
The total area coverage by starspots is of interest for a variety of reasons, but direct techniques only provide estimates of this important quantity. Sunspot areas exhibit a logno…
On the intensity contrast of solar photospheric faculae and network elements
A. Ortiz, S. K. Solanki, V. Domingo +2
Sunspots, faculae and the magnetic network contribute to solar irradiance variations. The contribution due to faculae and the network is of basic importance, but suffers from consi…