English
Related papers

Related papers: Two New Methods for Counting and Tracking the Evol…

200 papers

The distribution and evolution of the magnetic field at the solar poles through a solar cycle is an important parameter in understanding the solar dynamo. The accurate observations of the polar magnetic flux is very challenging from the…

Solar and Stellar Astrophysics · Physics 2024-07-26 Sanjay Gosain , Han Uitenbroek

The inherent stochastic and nonlinear nature of the solar dynamo makes the strength of the solar cycles vary in a wide range, making it difficult to predict the strength of an upcoming solar cycle. Recently, our work has shown that by using…

Solar and Stellar Astrophysics · Physics 2024-12-25 Akash Biswas

Macrospicules are relatively large spicule-like formations found mainly over the polar coronal holes when observing in the transition region spectral lines. In this study, we took advantage of the two short series of observations in the He…

Solar and Stellar Astrophysics · Physics 2017-01-04 I. P. Loboda , S. A. Bogachev

In addition to sunspots, which represent the most easily visualized manifestation of solar magnetism, cutting-edge observations of the solar atmosphere have uncovered a plethora of magnetic flux tubes, down to the resolving power of modern…

Solar and Stellar Astrophysics · Physics 2025-02-27 M. Stangalini , G. Verth , V. Fedun , D. Perrone , M. Berretti , P. Bushby , S. Jafarzadeh , D. B. Jess , F. Giannattasio , P. H. Keys , R. Bruno , F. Berrilli

Stellar activity is the major roadblock on the path to finding true Earth-analogue planets with the Doppler technique. Thus, identifying new indicators that better trace magnetic activity (i.e. faculae and spots) is crucial to aid in…

We estimated photospheric velocities by separately applying the Fourier Local Correlation Tracking (FLCT) and Differential Affine Velocity Estimator (DAVE) methods to 2708 co-registered pairs of SOHO/MDI magnetograms, with nominal 96-minute…

Solar and Stellar Astrophysics · Physics 2009-11-13 B. T. Welsch , Y. Li , P. W. Schuck , G. H. Fisher

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the most sensitive radio telescope for pulsar observations. We make polarimetric measurements of a large number of faint and distant pulsars using the FAST. We present the…

Astrophysics of Galaxies · Physics 2022-12-01 Jun Xu , Jinlin Han , Pengfei Wang , Yi Yan

We aim to gain insight into the effect of network and faculae on solar irradiance from their apparent intensity. Taking full-disc observations from the Solar Dynamics Observatory, we examined the intensity contrast of network and faculae in…

Solar and Stellar Astrophysics · Physics 2021-02-19 K. L. Yeo , N. A. Krivova

New radiative lifetimes, measured to $\pm$ 5 % accuracy, are reported for 31 even-parity levels of Fe I ranging from 45061 cm$^{-1}$ to 56842 cm$^{-1}$. These lifetimes have been measured using single-step and two-step time-resolved…

Solar and Stellar Astrophysics · Physics 2015-06-23 E. A. Den Hartog , M. P. Ruffoni , J. E. Lawler , J. C. Pickering , K. Lind , N. R. Brewer

Sun-like stars show intensity fluctuations on a number of time scales due to various physical phenomena on their surfaces. These phenomena can convincingly be studied in the frequency spectra of these stars - while the strongest signatures…

Solar and Stellar Astrophysics · Physics 2015-06-15 C. Karoff , T. L. Campante , J. Ballot , T. Kallinger , M. Gruberbauer , R. A. Garcia , D. A. Caldwell , J. L. Christiansen , K. Kinemuchi

The solar brightness varies on timescales from minutes to decades. A clear identification of the physical processes behind such variations is needed for developing and improving physics-based models of solar brightness variability and…

Solar and Stellar Astrophysics · Physics 2015-09-30 A. I. Shapiro , S. K. Solanki , N. A. Krivova , R. V. Tagirov , W. K. Schmutz

We combine observations of the Coronal Multi-channel Polarimeter (CoMP) and the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) to study the characteristic properties of (propagating) Alfvenic motions and…

Solar and Stellar Astrophysics · Physics 2015-07-02 Jiajia Liu , Scott W. McIntosh , Ineke De Moortel , Yuming Wang

We use seeing-free high spatial resolution Ca II H data obtained by the SUNRISE observatory to determine properties of slender fibrils in the lower solar chromosphere. In this work we use intensity images taken with the SUFI instrument in…

Accurately modeling the solar magnetic field is important for understanding long-term solar activity and space weather, but it is challenging due to limited observations, especially near the poles. The Surface Flux Transport (SFT) model…

Solar and Stellar Astrophysics · Physics 2026-03-25 Subhadip Pal , Gopal Hazra , Sudip Mandal

(Abridged) Aim: We attempt to determine robust estimates of the heliospheric magnetic flux ($\Phi_H$) using Parker Solar Probe (PSP) data, analyze how susceptible this is to overestimation compared to the true open flux ($\Phi_{open}$),…

We developed a method to automatically detect and trace solar filaments in H\alpha\ full-disk images. The program is able not only to recognize filaments and determine their properties, such as the position, the area, the spine, and other…

Solar and Stellar Astrophysics · Physics 2015-06-15 Qi Hao , Cheng Fang , P. F. Chen

Aims: The statistics of the photospheric granulation pattern are investigated using continuum images observed by Solar Dynamic Observatory (SDO)/Helioseismic and Magnetic Imager (HMI) taken at 6713~\AA. Methods: The supergranular boundaries…

Solar and Stellar Astrophysics · Physics 2019-06-19 Majedeh Noori , Mohsen Javaherian , Hossein Safari , Hamid Nadjari

Flare productivity varies among solar active regions (ARs). This study analyzed 20 ARs of contrasting sunspot areas and flare productivities to understand the super flare productivity of certain ARs. We used the flare index (FI) as an…

Solar and Stellar Astrophysics · Physics 2023-12-27 Suman K. Dhakal , Jie Zhang

Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every 22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are…

Solar and Stellar Astrophysics · Physics 2024-11-27 Rafael A. Garcia , Sylvain N. Breton , David Salabert , Sushant C. Tripathy , Kiran Jain , Savita Mathur , Eva Panetier

Parker Solar Probe (PSP) data recorded within a heliocentric radial distance of 0.3 AU have revealed a magnetic field dominated by Alfv\'enic structures that undergo large local variations or even reversals of the radial magnetic field.…