Related papers: On SH Molecules in Umbral Spectra
The magnetic properties of the umbra-penumbra (UP) boundary of sunspots and the boundary of pores at various evolutionary stages have been characterised using datasets from different instruments. We aim to study the differences between the…
Several studies have reported magnetic field fluctuations associated with umbral shock waves. We aim to study the properties and origin of magnetic field fluctuations in the umbral chromosphere. Temporal series of spectropolarimetric…
Finding low-mass planets around solar-type stars requires to understand the physical variability of the host star, which greatly exceeds the planet-induced radial-velocity modulation. Different solar photospheric absorption lines have…
New laboratory data of ethyl mercaptan, CH$_{3}$CH$_{2}$SH, in the millimeter and submillimeter-wave domains (up to 880 GHz) provided very precise values of the spectroscopic constants that allowed the detection of $gauche$-CH$_3$CH$_2$SH…
We review the coronal visible and infrared lines, collecting previous observations, and comparing, whenever available, observed radiances with those predicted by various models: the quiet Sun, a moderately active Sun, and an active region…
One of the greatest challenges in solar and stellar physics in coming years will be to observe the Second Solar Spectrum with a spatial resolution significantly better than 1 arcsec. This type of scattering polarization observations would…
Umbral dots (UDs) were observed using the 1.6 meter solar telescope. Achieved conventional diffraction limit in the TiO 705.68 nm spectral line used was 0.1". The 418 UDs were analysed. Median diameter was 0.5'' and median intensity…
We study the velocity structure of penumbral filaments in the deep photosphere to obtain direct evidence for the convective nature of sunspot penumbrae. A sunspot was observed at high spatial resolution with the 1-m Swedish Solar Telescope…
The analyses of sunspot observations revealed a fundamental magnetic property of the umbral boundary, the invariance of the vertical component of the magnetic field. We aim to analyse the magnetic properties of the umbra-penumbra boundary…
12 stable single sunspots were investigated in two aspects. The outer boundaries of the sunspots umbra were determined by an independent mathematical method and the vertical component of the magnetic field at these boundaries was found. We…
Umbral dots (UDs) are small-scale convective intrusions in the umbral core of sunspots and pores. Different methods have been used in the past to determine the physical properties of UDs. One of the methods typically used is multi-level…
The instrumental advances made in this new era of 4-meter class solar telescopes with unmatched spectropolarimetric accuracy and sensitivity, will enable the study of chromospheric magnetic fields and their dynamics with unprecedented…
In this study, we investigate magnetic properties of umbra of magneto-conjugate leading and following sunspots, i.e. connected through magnetic field lines. We established dependences between individual sunspot umbra field characteristics,…
We report the first detection of interstellar mercapto radicals, obtained along the sight-line to the submillimeter continuum source W49N. We have used the GREAT instrument on SOFIA to observe the 1383 GHz Doublet Pi 3/2 J = 5/2 - 3/2…
The influence of the convective structure of the solar photosphere on the shifts of spectral lines of iron was studied. Line profiles in the visible and infrared spectrum were synthesized with the use of 2-D time-dependent hydrodynamic…
The high spatial and time resolution data obtained with SDO/AIA for the sunspot in active region NOAA 11131 on 08 December 2010 were analysed with the time-distance plot technique and the pixelised wavelet filtering method. Oscillations in…
Spatial distributions of the dominant oscillation frequency obtained for four sunspots show a feature shared by all the analysed levels of the solar atmosphere in these sunspots. This feature located in the inner penumbrae indicates that…
Millimter (mm) frequencies are primarily sensitive to thermal emission from layers across the stellar chromosphere up to the transition region, while metrewave (radio) frequencies probe the coronal heights. Together the mm and radio band…
Observations of quiet Sun from the Solar Optical Telescope/Spectro-Polarimeter (SOT/SP) aboard the Hinode spacecraft would reveal the magnetic characters of the solar photosphere. By making use of the deep mode observations of three quiet…
It was empirically determined that the umbra-penumbra boundaries of stable sunspots are characterized by a constant value of the vertical magnetic field. We analyzed the evolution of the photospheric magnetic field properties of a decaying…