In the present work a statistical investigation of the spatial distribution of longitudinal coordinates of sunspot data has been carried out. For the analysis the maximal area of umbra plus penumbra of sunspot groups has been taken into account. Spatial distributions of longitudinal coordinates of sunspot data are obtained in diierent coordinate systems (e.g. Carrington, equatorial and diierent...

■ Abstract Important physical processes on the Sun, and especially in sunspots, occur on spatial scales at or below the limiting resolution of current solar telescopes. Over the past decade, using a number of new techniques, high-resolution observations have begun to reveal the complex thermal and magnetic structure of a sunspot, along with associated flows and oscillations. During this time re...

A new technique is presented for automatic identification of sunspots on the full disk solar images allowing robust detection of sunspots on images obtained from space and ground observations, which may be distorted by weather conditions and instrumental artefacts. The technique applies image cleaning procedures for elimination of limb darkening, intensity noise and noncircular image shape. Sob...

We present conspicuous activities of plasma ejections along a light bridge of a stable and mature sunspot in NOAA 8971 on 2000 May 02. We found the ejections both in the Hα (10 K) images obtained with the Domeless Solar Telescope (DST) at Hida Observatory, and in the 171 Å (Fe ix/x, ∼106 K) images obtained with the Transition Region and Coronal Explorer (TRACE). Main characteristics of the ejec...

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 spectropolarimetric time series of the photospheric Si i 10827 Å line and the chromospheric He i 10830 Å multiplet were inverted using a MilneEddington atmosphere. Spatial pixels were paired between the outer umbral/inner penumbra...

Time-distance helioseismic measurements in surfaceand deep-focus geometries for wave-paths that distinguish surface magnetic contributions from those due to deeper perturbations beneath a large sunspot are presented and analysed. Travel times showing an increased wave speed region extending down to about 18 Mm beneath the spot are detected in deep-focus geometry that largely avoids use of wave ...

It is of great importance to monitor large solar active regions in the far-side of the Sun for space weather forecast, in particular, to predict their appearance before they rotate into our view from the solar east limb. Local helioseismology techniques, including helioseismic holography and time-distance, have successfully imaged solar far-side active regions. In this Letter, we further explor...

We report on the discovery of mostly horizontal field channels just outside sunspot penumbrae (in the so-called ‘moat’ region) that are seen to sustain supersonic flows (line-of-sight component of 6 km s). The spectral signature of these supersonic flows corresponds to circular polarization profiles with an additional, satellite, third lobe of the same sign as the parent sunspot’ Stokes V blue ...

Using high-resolution ring analysis (HRRA) we deduce subsurface flows within magnetic active regions and within quiet sun. With this procedure we are capable of measuring flows with a horizontal spatial resolution of 2◦ in heliographic angle (or roughly 20 Mm). From the resulting flow fields we deduce mean inflow rates into active regions, mean circulation speeds around active regions, and prob...

The star closest to our Earth is the sun with an average distance of 149,680,000 km. plasma a very high temperature. most easily observed solar activity from are sunspots and flares, where flares on can affect Earth’s atmosphere. Therefore this, research was carried out in February - April 2022 at Laboratory Astronomy Physics, State University Malang geographical location 07° 57’ 39” South Lati...