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Related papers: Solar activity classification based on Mg II spect…

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Solar trajectory monitoring is a pivotal challenge in solar energy systems, underpinning applications such as autonomous energy harvesting and environmental sensing. A prevalent failure mode in sustained solar tracking arises when the…

Over the past few decades, many applications of physics-based simulations and data-driven techniques (including machine learning and deep learning) have emerged to analyze and predict solar flares. These approaches are pivotal in…

Solar and Stellar Astrophysics · Physics 2024-02-07 Anli Ji , Berkay Aydin

Stellar flares cannot be spatially resolved, which complicates ascertaining the physical processes behind particular spectral signatures. Due to their proximity to Earth, solar flares can serve as a stepping stone for understanding their…

This paper explores the application of machine learning methods for classifying astronomical sources using photometric data, including normal and emission line galaxies (ELGs; starforming, starburst, AGN, broad line), quasars, and stars. We…

This study explores the use of historical data from Global Navigation Satellite System (GNSS) scintillation monitoring receivers to predict the severity of amplitude scintillation, a phenomenon where electron density irregularities in the…

Signal Processing · Electrical Eng. & Systems 2024-09-04 Sultan Halawa , Maryam Alansaari , Maryam Sharif , Amel Alhammadi , Ilias Fernini

This study addresses the prediction of geomagnetic disturbances by exploiting machine learning techniques. Specifically, the Long-Short Term Memory recurrent neural network, which is particularly suited for application over long time…

Solar flares are defined as outbursts on the surface of the Sun. They occur when energy accumulated in magnetic fields enclosing solar active regions (ARs) is abruptly expelled. Solar flares and associated coronal mass ejections are sources…

Solar and Stellar Astrophysics · Physics 2025-02-24 Huseyin Cavus , Jason T. L. Wang , Teja P. S. Singampalli , Gani Caglar Coban , Hongyang Zhang , Abd-ur Raheem , Haimin Wang

Surface solar irradiance varies on scales as small as seconds or meters due to scattering and absorption by the atmosphere. Clouds are the main driver of this variability, but moisture structures in the atmospheric boundary layer and…

Atmospheric and Oceanic Physics · Physics 2024-04-08 Wouter Mol , Bert Heusinkveld , Mary Rose Mangan , Oscar Hartogensis , Menno Veerman , Chiel van Heerwaarden

Solar irradiance and its variations in the ultraviolet (UV) control the photochemistry in Earth's atmosphere and influence Earth's climate. The variability of Mg II h and k core-to-wing ratio, also known as the Mg II index, is highly…

Solar and Stellar Astrophysics · Physics 2025-01-07 K. Sowmya , M. Snow , A. I. Shapiro , N. A. Krivova , T. Chatzistergos , S. K. Solanki

The Rapid Oscillations in the Solar Atmosphere (ROSA) instrument reveals solar atmospheric fluctuations at high frequencies. Spectra of variations of the G-band intensity (IG) and CaII K-line intensity (IK) show correlated fluctuations…

Solar and Stellar Astrophysics · Physics 2015-06-03 J. K. Lawrence , A. C. Cadavid , D. J. Christian , D. B. Jess , M. Mathioudakis

As compared to simple actions, activities are much more complex, but semantically consistent with a human's real life. Techniques for action recognition from sensor generated data are mature. However, there has been relatively little work…

Computer Vision and Pattern Recognition · Computer Science 2016-11-08 Ye Liu , Liqiang Nie , Lei Han , Luming Zhang , David S Rosenblum

Using solar power in the process industry can reduce greenhouse gas emissions and make the production process more sustainable. However, the intermittent nature of solar power renders its usage challenging. Building a model to predict…

Systems and Control · Electrical Eng. & Systems 2022-05-17 Yu Yang , Jia Mao , Richard Nguyen , Annas Tohmeh , Hen-Geul Yeh

Adverse space weather effects can often be traced to solar flares, prediction of which has drawn significant research interests. The Helioseismic and Magnetic Imager (HMI) produces full-disk vector magnetograms with continuous high cadence,…

Solar and Stellar Astrophysics · Physics 2017-07-26 Chang Liu , Na Deng , Jason T. L. Wang , Haimin Wang

The characterization of solar surface differential rotation (SDR) from disk-integrated chromospheric measurements has important implications for the study of differential rotation and dynamo processes in other stars. Some chromospheric…

Solar and Stellar Astrophysics · Physics 2015-06-11 Luca Bertello , Alexei A. Pevtsov , A. Pietarila

Accurately characterizing intrinsic stellar photometric noise induced by stellar astrophysics, such as stellar activity, granulation, and oscillations, is of crucial importance for detecting transiting exoplanets. In this study, we…

Solar and Stellar Astrophysics · Physics 2024-04-23 Jinghua Zhang , Maosheng Xiang , Jie Yu , Jian Ge , Ji-Wei Xie , Hui Zhang , Yaguang Li , You Wu , Chun-Qian Li , Shaolan Bi , Hong-Liang Yan , Jian-Rong Shi

We analyze space- and ground-based data for the old ($7.0\pm0.3$~Gyr) solar analogs 16 Cyg A and B. The stars were observed with the Cosmic Origins UV Spectrographs on the Hubble Space Telescope (HST) on 23 October 2015 and 3 February 2016…

Solar and Stellar Astrophysics · Physics 2017-12-07 Philip Judge , RIcky Egeland , Travis Metcalfe , Edward Guinan , Scott Engel

Stellar activity can be observed at different wavelengths in a variety of different activity indicators. We investigated the correlation between coronal and chromospheric emissions by combining X-ray data from stars detected in the eROSITA…

Solar and Stellar Astrophysics · Physics 2025-04-25 S. Freund , S. Czesla , B. Fuhrmeister , P. Predehl , J. Robrade , P. C. Schneider , J. H. M. M. Schmitt

This paper presents a theoretical investigation on the polarization and magnetic sensitivity of the near-ultraviolet (near-UV) solar spectral lines of Fe II between 250 and 278 nm. In recent years, UV spectropolarimetry has become key to…

Solar and Stellar Astrophysics · Physics 2023-05-17 David Afonso Delgado , Tanausú del Pino Alemán , Javier Trujillo Bueno

Many studies of the solar corona have shown that the observed X-ray luminosity is well correlated with the total unsigned magnetic flux. In this paper we present results from the extensive numerical modeling of active regions observed with…

Astrophysics · Physics 2016-08-30 Harry P. Warren , Amy R. Winebarger