Results 1 to 10 of about 4,318,459 (158)

A Superflare on YZ Canis Minoris Observed by the Seimei Telescope and TESS: Red Asymmetry of Hα Emission Associated with White-light Emission

The Astrophysical Journal, 2023
Active M-type stars are known to often produce superflares on the surface. Radiation from stellar (super)flares is important for exoplanet habitability, but the mechanisms are not well understood.
Keiichi Namizaki, Kosuke Namekata, Hiroyuki Maehara, Yuta Notsu, Satoshi Honda, Daisaku Nogami, Kazunari Shibata   +6 more
doaj   +1 more source

A Census of Near-UV M-dwarf Flares Using Archival GALEX Data and the gPHOTON2 Pipeline

The Astrophysical Journal, 2023
M-dwarfs are common stellar hosts of habitable-zone exoplanets. Near-UV (NUV) radiation can severely impact the atmospheric and surface conditions of such planets, making the characterization of NUV flaring activity a key aspect in determining ...
Param Rekhi, Sagi Ben-Ami, Volker Perdelwitz, Yossi Shvartzvald   +3 more
doaj   +1 more source

A 7 Day Multiwavelength Flare Campaign on AU Mic. I. High-time-resolution Light Curves and the Thermal Empirical Neupert Effect

The Astrophysical Journal, 2023
We present light curves and flares from a 7 day, multiwavelength observational campaign of AU Mic, a young and active dM1e star with exoplanets and a debris disk. We report on 73 unique flares between the X-ray to optical data.
Isaiah I. Tristan, Yuta Notsu, Adam F. Kowalski, Alexander Brown, John P. Wisniewski, Rachel A. Osten, Eliot H. Vrijmoet, Graeme L. White, Brad D. Carter, Carol A. Grady, Todd J. Henry, Rodrigo H. Hinojosa, Jamie R. Lomax, James E. Neff, Leonardo A. Paredes, Jack Soutter   +15 more
doaj   +1 more source

Characterizing Temperatures of Flares on the M Dwarf Wolf 359 from Simultaneous Multiband Optical Observations

The Astronomical Journal
We present a flare temperature study of the highly active M dwarf Wolf 359 using simultaneous multiband ( u , g , r , i , and z ) photometric observations from the Lulin 1 m and 41 cm telescopes.
Chia-Lung Lin, Li-Ching Huang, Wei-Jie Hou, Hsiang-Yao Hsiao, Wing-Huen Ip   +4 more
doaj   +1 more source

Time-dependent Stellar Flare Models of Deep Atmospheric Heating

The Astrophysical Journal
Optical flares have been observed from magnetically active stars for many decades; unsurprisingly, the spectra and temporal evolution are complicated.
Adam F. Kowalski, Joel C. Allred, Mats Carlsson   +2 more
doaj   +1 more source

The White-light Superflares from Cool Stars in GWAC Triggers

The Astrophysical Journal
M-type stars are the ones that flare most frequently, but how big their maximum flare energy can reach is still unknown. We present 163 flares from 162 individual M2 through L1-type stars that triggered the GWAC, with flare energies ranging from 10 ^32.2
Guang-Wei Li, Liang Wang, Hai-Long Yuan, Li-Ping Xin, Jing Wang, Chao Wu, Hua-Li Li, Hasitieer Haerken, Wei-Hua Wang, Hong-Bo Cai, Xu-Hui Han, Yang Xu, Lei Huang, Xiao-Meng Lu, Jian-Ying Bai, Xiang-Yu Wang, Zi-Gao Dai, En-Wei Liang, Jian-Yan Wei   +18 more
doaj   +1 more source

A 7 Day Multiwavelength Flare Campaign on AU Mic. IV. Quiescent Gyrosynchrotron and Gyroresonance Radiation from 12 to 25 GHz

The Astrophysical Journal
We present an analysis of the radio quiescent data from a multiwavelength campaign of the active M dwarf flare star AU Mic (dM1e) that occurred in 2018 October. Using Ku -band data (12–18 GHz) from the Karl G. Jansky Very Large Array and K -band data (17–
Isaiah I. Tristan, Rachel A. Osten, Yuta Notsu, Adam F. Kowalski, Steven R. Cranmer   +4 more
doaj   +1 more source

A Single Power Law for the TRAPPIST-1 Flare Distribution across 4 Orders of Magnitude in Energy

The Astrophysical Journal Letters
TRAPPIST-1 is an ultracool dwarf that flares frequently. These flares shape the surrounding planets’ high-energy irradiation environment, with consequences for atmospheric chemistry and escape, and they can contaminate transmission spectroscopy of those ...
Valeriy Vasilyev, Alexander I. Shapiro, Nadiia Kostogryz, Chia-Lung Lin, Greg Kopp, Benjamin V. Rackham, Astrid M. Veronig, Olivia Lim, Julien de Wit, Daniel Apai, Laurent Gizon, Sami K. Solanki, Sara Seager   +12 more
doaj   +1 more source

Rising Near-ultraviolet Spectra in Stellar Megaflares

The Astrophysical Journal
Flares from M dwarf stars can attain energies up to 10 ^4 times larger than solar flares but are generally thought to result from similar processes of magnetic energy release and particle acceleration.
Adam F. Kowalski, Rachel A. Osten, Yuta Notsu, Isaiah I. Tristan, Antigona Segura, Hiroyuki Maehara, Kosuke Namekata, Shun Inoue   +7 more
doaj   +1 more source

Flaring Activity for Low-mass Stars in the β Pictoris Moving Group

The Astronomical Journal
Stellar flares from K and M dwarfs release panchromatic radiation characterized by a significantly higher brightness temperature (∼9–20 kK) than the star. The increased frequency of magnetic activity on young low-mass stars results in the energy released
Jordan N. Ealy, Joshua E. Schlieder, Thaddeus D. Komacek, Emily A. Gilbert   +3 more
doaj   +1 more source