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Related papers: Steps toward a high precision solar rotation profi…

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The daily measurements of the disc-integrated solar radio flux, observed by the Radio Solar Telescope Network (RSTN), at 245, 410, 610, 1415, 2695, 4995, and 8800 MHz during the time interval of 1989 January 1 to 2019 December 17, are used…

Solar and Stellar Astrophysics · Physics 2024-11-28 N. B. Xiang , X. H. Zhao , L. H. Deng , F. Y. Li , Y. J. Wang , X. W. Tan

The solar images at 17 GHz by Nobeyama Radio Heliograph and in X-ray by soft X-ray telescope (SXT) on board Yohkoh satellite have been of particular interest for the estimation of solar coronal rotation using flux modulation approach. These…

Solar and Stellar Astrophysics · Physics 2015-05-27 Hari Om Vats , Satish Chandra

Identification of solar coronal holes (CHs) provides information both for operational space weather forecasting and long-term investigation of solar activity. Source data for the first problem are typically most recent solar disk…

Solar and Stellar Astrophysics · Physics 2020-11-18 Egor Illarionov , Alexander Kosovichev , Andrey Tlatov

Three-minute oscillations over sunspot's umbra in AR 11131 were observed simultaneously in UV/EUV emission by SDO/AIA and in radio emission by Nobeyama Radioheliograph (NoRH). We use 24-hours series of SDO and 8-hours series of NoRH…

Solar and Stellar Astrophysics · Physics 2015-05-30 V. E. Reznikova , K. Shibasaki , R. A. Sych , V. M. Nakariakov

Helioseismic signatures of dynamo waves have recently been discovered in variations of the solar differential rotation, offering valuable insights into the type of dynamo mechanism operating in the solar convection zone. To characterize…

Solar and Stellar Astrophysics · Physics 2025-05-19 Krishnendu Mandal , Alexander G. Kosovichev , Valery V. Pipin , Sylvain G. Korzennik

We analyzed the sunspot-group daily data that were reported by Greenwich Photoheliogrphic Results (GPR) during the period 1874-1976 and Debrecen Photoheliographic Data (DPD) during the period 1977-2017. We determined the equatorial rotation…

Solar and Stellar Astrophysics · Physics 2020-12-04 J. Javaraiah

The variation of solar irradiance is one of the natural forcing mechanisms of the terrestrial climate. Hence, the time-dependent solar irradiance is an important input parameter for climate modelling. The solar surface magnetic field is a…

Solar and Stellar Astrophysics · Physics 2015-05-11 Omar Ashamari , Rami Qahwaji , Stan Ipson , Micha Scholl , Omar Nibouche , Margit Haberreiter

A new instrument was designed to take visible-light (VL) polarized brightness ($pB$) observations of the solar corona during the 14 December 2020 total solar eclipse. The instrument, called the Coronal Imaging Polarizer (CIP), consisted of…

Solar and Stellar Astrophysics · Physics 2023-10-16 Liam T. Edwards , Kaine A. Bunting , Brad Ramsey , Matthew Gunn , Tomos Fearn , Thomas Knight , Gabriel Domingo Muro , Huw Morgan

We present new Doppler images of both components of the double-lined binary $\sigma^{2}$ CrB, based on the high-resolution spectroscopic data collected during 11 nights in 2015 March--April. The observed spectra form two independent data…

A technique is described for measuring electrical currents in the solar corona. It uses radioastronomical polarization measurements of a spatially-extended radio source viewed through the corona. The observations yield the difference in the…

Astrophysics · Physics 2009-11-13 Steven R. Spangler

Young and active stars generally have regular, almost sinusoidal, patterns of variability attributed to their rotation, while the majority of older and less active stars, including the Sun, have more complex and non-regular light-curves…

Solar and Stellar Astrophysics · Physics 2020-04-22 E. M. Amazo-Gómez , A. I. Shapiro , S. K. Solanki , N. A. Krivova , G. Kopp , T. Reinhold , M. Oshagh , A. Reiners

In the field of planet and proto-planetary disk detection, achieving high angular resolution and high dynamic range is a necessity. Coronography coupled with adaptive optics on Hubble Space Telescope is a way to get both good spatial…

Astrophysics · Physics 2007-05-23 Fabien Malbet , Michael Shao , Jeffrey Yu

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…

Solar and Stellar Astrophysics · Physics 2024-12-25 Dibya Kirti Mishra , Srinjana Routh , Bibhuti Kumar Jha , Subhamoy Chatterjee , Dipankar Banerjee

We present a study on the determination of rotation periods (P) of solar-like stars from the photometric irregular time-sampling of the ESA Gaia mission, currently scheduled for launch in 2013, taking into account its dependence on ecliptic…

Solar and Stellar Astrophysics · Physics 2015-06-04 E. Distefano , A. C. Lanzafame , A. F. Lanza , S. Messina , A. J. Korn , K. Eriksson , J. Cuypers

DEM analysis is a major diagnostic tool for stellar atmospheres. But both its derivation and its interpretation are notably difficult because of random and systematic errors, and the inverse nature of the problem. We use simulations with…

Solar and Stellar Astrophysics · Physics 2013-06-17 Chloé Guennou , Frédéric Auchère , Elie Soubrié , Karine Bocchialini , Susanna Parenti

We employ a sequence of Doppler images obtained with the Coronal Multi-channel Polarimeter (CoMP) instrument to perform time-distance seismology of the solar corona. We construct the first k-omega diagrams of the region. These allow us to…

Solar and Stellar Astrophysics · Physics 2010-01-15 Steven Tomczyk , Scott W. McIntosh

Coronal holes are the observational manifestation of the solar magnetic field open to the heliosphere and are of pivotal importance for our understanding of the origin and acceleration of the solar wind. Observations from space missions…

We present a method to derive outflow velocities in the solar corona using different data sets including solar wind mass flux coming from the SWAN/SOHO instrument, electron density values from LASCO-C2 and interplanetary solar wind…

Astrophysics · Physics 2009-11-13 E. Quemerais , R. Lallement , D. Koutroumpa , P. Lamy

In a previous paper, I described a new way of determining the high-latitude solar rotation rate statistically from space-time maps of polar faculae observed in the 6767 \r{A} continuum by the Michelson Doppler Interferometer (MDI) on the…

Solar and Stellar Astrophysics · Physics 2025-02-04 Neil R. Sheeley

We present a first systematic study on the cross-sectional temperature structure of coronal loops using the six coronal temperature filters of the Atmospheric Imaging Assembly (AIA) instrument on the Solar Dynamics Observatory (SDO). We…

Solar and Stellar Astrophysics · Physics 2015-05-27 Markus J. Aschwanden , Paul Boerner