English
Related papers

Related papers: Similarities and differences between solar and ste…

200 papers

We present the analysis of three kinds of oscillating behavior using multi-wavelength observations of the 10 November 2013 (SOL2013-11-10T05:14) circular-ribbon flare. This event is a typical circular-ribbon flare with an outer spine…

Solar and Stellar Astrophysics · Physics 2022-01-12 Zongjun Ning , Ya Wang , Zhenxiang Hong , Dong Li

Although late-type dwarfs and giant stars are substantially different, their flares are thought to originate in similar physical processes and differ only by a scale factor in the energy levels. We study the validity of this approach. We…

Solar and Stellar Astrophysics · Physics 2022-12-14 Katalin Oláh , Bálint Seli , Zsolt Kővári , Levente Kriskovics , Krisztián Vida

We report the discovery of 31 blue, short period, pulsators made using data taken as part of the Rapid Temporal Survey (RATS). We find they have periods between 51-83 mins and full-amplitudes between 0.05-0.65 mag. Using the…

Solar and Stellar Astrophysics · Physics 2015-05-28 Gavin Ramsay , Ralf Napiwotzki , Thomas Barclay , Pasi Hakala , Stephen Potter , Mark Cropper

We investigate the origin of very long-periodic pulsations (VLPs) in the white-light emission of an X6.4 flare on 2024 February 22 (SOL2024-02-22T22:08), which occurred at the edge of a sunspot group. The flare white-light fluxes reveal…

Solar and Stellar Astrophysics · Physics 2024-08-29 Dong Li , Jincheng Wang , Yu Huang

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…

The relativistic plasma flows onto neutron stars that are accreting material from stellar companions can be used to probe strong-field gravity as well as the physical conditions in the supranuclear-density interiors of neutron stars. Plasma…

Recent polarimetric mm-observations of the galactic centre by Wielgus et al. (2022a) showed sinusoidal loops in the Q-U plane with a duration of one hour. The loops coincide with a quasi-simultaneous X-ray flare. A promising mechanism to…

High Energy Astrophysical Phenomena · Physics 2023-09-01 Mahdi Najafi-Ziyazi , Jordy Davelaar , Yosuke Mizuno , Oliver Porth

We use data from the MeerTime project on the MeerKAT telescope to ask whether the radio emission properties of millisecond pulsars (MSPs) and slowly rotating, younger pulsars (SPs) are similar or different. We show that the flux density…

High Energy Astrophysical Phenomena · Physics 2024-07-10 A. Karastergiou , S. Johnston , B. Posselt , L. S. Oswald , M. Kramer , P. Weltevrede

Solar flares are observed and classified according to their intensity measured with the GOES X-ray Sensors. We show that the duration of a flare, as measured by the full width at half maximum (FWHM) in GOES is not related to the size of the…

Solar and Stellar Astrophysics · Physics 2019-04-10 Jeffrey W. Reep , Kalman J. Knizhnik

The dynamo process is believed to drive the magnetic activity of stars like the Sun that have an outer convection zone. Large spectroscopic surveys showed that there is a relation between the rotation periods and the cycle periods: the…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. Mathur , R. A. Garcia , J. Ballot , T. Ceillier , D. Salabert , T. S. Metcalfe , C. Regulo , A. Jimenez , S. Bloemen

We describe microwave and hard X-ray observations of strong quasiperiodic pulsations from the GOES X1.3 solar flare on 15 June 2003. The radio observations were made jointly by the Owens Valley Solar Array (OVSA), the Nobeyama Polarimeter…

Astrophysics · Physics 2009-11-13 G. D. Fleishman , T. S. Bastian , D. E. Gary

Precise, high-cadence, long-term records of stellar spectral variability at different temporal scales lead to better understanding of a wide variety of phenomena including stellar atmospheres and dynamos, convective motions, and rotational…

Solar and Stellar Astrophysics · Physics 2023-07-19 Serena Criscuoli , Sergey Marchenko , Matthew DeLand , Debi Choudhary , Greg Kopp

Quasi-periodic oscillations have been seen in the light curves following several magnetar giant flares. These oscillations are of great interest as they probably provide our first ever view of the normal modes of oscillation of neutron…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. Glampedakis , D. I. Jones

Using data from observations made with XMM-Newton, we present an X-ray analysis of two flares observed in $\xi$ Boo. The flare loop parameters are derived using various loop models including state-of-the-art hydrodynamic flare model. The…

Solar and Stellar Astrophysics · Physics 2017-08-02 J. C. Pandey , A. K. Srivastava

We use photometric observations of solar-type stars, made by the NASA Kepler Mission, to conduct a statistical study of the impact of stellar surface activity on the detectability of solar-like oscillations. We find that the number of stars…

Low-frequency longitudinal oscillations of a flaring coronal loop are studied numerically. In the recent work of Nakariakov et al., Astron. and Astrophys., 414, L25-L28 (2004) it has been shown that the time dependences of density and…

Astrophysics · Physics 2009-11-10 D. Tsiklauri , V. M. Nakariakov , T. D. Arber , M. J. Aschwanden

The excitation mechanism of coronal quasi-period fast-propagating (QFP) wave trains remains unresolved. Using Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory observations, we study a narrow and a broad QFP wave train…

Solar and Stellar Astrophysics · Physics 2024-01-15 Xinping Zhou , Yuandeng Shen , Chengrui Zhou , Zehao Tang , Ahmed Ahmed Ibrahim

The length of the asteroseismic timeseries obtained from the Kepler satellite analysed here span 19 months. Kepler provides the longest continuous timeseries currently available, which calls for a study of the influence of the increased…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. Hekker , Y. Elsworth , B. Mosser , T. Kallinger , W. J. Chaplin , J. De Ridder , R. A. Garcia , D. Stello , B. D. Clarke , J. R. Hall , K. A. Ibrahim

On the basis of the 30-year ago ground-based photometry and the recent Kepler space experiment there have been considered frequencies of occurrence and energetics of the solar-type stellar flares. It was concluded that frequencies of…

Solar and Stellar Astrophysics · Physics 2015-08-04 R. E. Gershberg

Cool main-sequence, sub-giant and red-giant stars all show solar-like oscillations, pulsations that are excited and intrinsically damped by near-surface convection. Many overtones are typically excited to observable amplitudes, giving a…

Solar and Stellar Astrophysics · Physics 2019-04-17 William J. Chaplin , Heather M. Cegla , Christopher A. Watson , Guy R. Davies , Warrick H. Ball