Results 31 to 40 of about 34,279 (294)

Optical properties of impulsive flares

The Astrophysical Journal Supplement Series, 1990
The optical and morphological properties of impulsive flares are examined, showing that all impulsive flares occur close to sunspots and on magnetic inversion lines with steep gradients. Impulsive flares are defined and flare brightness variations and the magnetic structure of flares are discussed.
Harold Zirin, Frances Tang
openaire   +1 more source

Multiwavelength Observations of 6 BL Lac Objects in 2008-2012

EPJ Web of Conferences, 2013
We present results of 4 years of VLBA monitoring along with γ-ray and optical R-band photometric observations of 6 BL Lac objects (3C 66A, S5 0716+71, PKS 0735+17, S4 0954+68, W Com, and OT 081).
Morozova D.A., Jorstad S.G., Marscher A.P., Larionov V.M., Troitskiy I.S., Blinov D.A., Agudo I., Smith P.S.   +7 more
doaj   +1 more source

Unusual Hard X-Ray Flares Caught in NICER Monitoring of the Binary Supermassive Black Hole Candidate AT2019cuk/Tick Tock/SDSS J1430+2303

The Astrophysical Journal Letters, 2023
The nuclear transient AT2019cuk/Tick Tock/SDSS J1430+2303 has been suggested to harbor a supermassive black hole (SMBH) binary near coalescence. We report results from high-cadence NICER X-ray monitoring with multiple visits per day from 2022 January to ...
Megan Masterson, Erin Kara, Dheeraj R. Pasham, Daniel J. D’Orazio, Dominic J. Walton, Andrew C. Fabian, Matteo Lucchini, Ronald A. Remillard, Zaven Arzoumanian, Otabek Burkhonov, Hyeonho Choi, Shuhrat A. Ehgamberdiev, Elizabeth C. Ferrara, Muryel Guolo, Myungshin Im, Yonggi Kim, Davron O. Mirzaqulov, Gregory S. H. Paek, Hyun-Il Sung, Joh-Na Yoon   +19 more
doaj   +1 more source

Variable polarisation and Doppler tomography of PSR J1023+0038 - Evidence for the magnetic propeller during flaring?

, 2017
Transitional millisecond pulsars are systems that alternate between an accreting low-mass X-ray binary (LMXB) state, and a non-accreting radio pulsar state.
Hakala, Pasi, Kajava, Jari J. E.
core   +1 more source

A Possible Mechanism for the “Late Phase” in Stellar White-light Flares

The Astrophysical Journal, 2023
M dwarf flares observed by the Transiting Exoplanet Survey Satellite (TESS) sometimes exhibit a peak-bump light-curve morphology, characterized by a secondary, gradual peak well after the main, impulsive peak.
Kai E. Yang, Xudong Sun, Graham S. Kerr, Hugh S. Hudson   +3 more
doaj   +1 more source

A Comprehensive Study of Gamma-Ray Burst Optical Emission: I. Flares and Early Shallow Decay Component

, 2012
Well-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are compiled from the literature. By empirical fitting we identify eight possible emission components and summarize the results in a "synthetic" lightcurve.
Barthelmy, Barthelmy, Bellm, Berger, Bing Zhang, Blandford, Butler, Butler, Butler, Chen, Chincarini, Cucchiara, Dai, Dainotti, Di Matteo, Donaghy, Drenkhahn, En-Wei Liang, Fan, Fenimore, Firmani, Fynbo, Gehrels, Ghirlanda, Giuliani, Golenetskii, Golenetskii, Golenetskii, Greiner, Grupe, Gu, He Gao, Hou-Jun Lü, Huang, Jaunsen, Jian-Yan Wei, Jie-Min Chen, Jin Zhang, Kann, Kann, Kann, Kann, Kobayashi, Kohri, Kohri, Krimm, Krimm, Krühler, Lian-Zhong Lü, Liang, Liang, Liang, Liang, Liang Li, Liu, Liu, Lü, Lü, Maxham, McBreen, Mészáros, Narayan, Nousek, O'Brien, Palmer, Panaitescu, Panaitescu, Panaitescu, Perley, Perna, Popham, Price, Prochaska, Qing-Wen Tang, Rees, Robertson, Rui-Jing Lu, Sagar, Sakamoto, Sakamoto, Sari, Sari, Schady, Schlegel, Shao-Qiang Xi, Shuang-Xi Yi, Soderberg, Thompson, Thompson, Troja, Uhm, Ukwatta, Urata, Yost, Yuan, Zhang, Zhang, Zhang, Zhang, Zhang, Zhang, Zhang, Zhang, Zhang   +103 more
core   +1 more source

Optical Flare Search on the RS CVn-type flare stars AR Lacertae

, 2022
We present the results of fast spectrophotometry of flares on the RS CVn-type star AR Lac with a time resolution of 34 s and a spectroscopic resolution R $\sim $ 1300. The observations were performed on July 21-22, 2021 with the 2.0 m Karl Zeiss telescope at the Terskol Observatory.
Markus, Ya. S., Zhilyaev, B. E.
openaire   +2 more sources

Magnetic Field Amplification and Flat Spectrum Radio Quasars

, 2014
We perform time-dependent, spatially-resolved simulations of blazar emission to evaluate several flaring scenarios related to magnetic-field amplification and enhanced particle acceleration.
Bailyn, Charles D., Boettcher, Markus, Bonning, Erin W., Buxton, Michelle, Chatterjee, Ritaban, Chen, Xuhui, Coppi, Paolo, Fossati, Giovanni, Isler, Jedidah, Maraschi, Laura, Pohl, Martin, Urry, Meg, Zhang, Haocheng   +12 more
core   +1 more source

Analysis and modeling of high temporal resolution spectroscopic observations of flares on AD Leo [PDF]

, 2006
We report the results of a high temporal resolution spectroscopic monitoring of the flare star AD Leo. During 4 nights, more than 600 spectra were taken in the optical range using the Isaac Newton Telescope (INT) and the Intermediate Dispersion ...
Abada-Simon, Abdul-Aziz, Abranin, Arzner, Audard, Ayres, B. H. Foing, Balega, Berdyugina, Butler, Byrne, Byrne, Canfield, Cargill, Chabrier, Crespo-Chacón, Cully, D. García-Alvarez, D. Montes, Datlowe, Delfosse, Ding, Donati-Falchi, Doyle, Doyle, Doyle, Doyle, Doyle, Drake, Eason, Favata, Forbes, Fuhrmeister, Gan, Garcia-Alvarez, García-Alvarez, Gershberg, Gershberg, Gray, Gunn, Gunn, Güdel, Güdel, Güdel, Haisch, Hawley, Hawley, Hawley, Heinzel, Henry, Houdebine, Houdebine, Houdebine, Houdebine, I. Crespo-Chacón, Ivanova, J. López-Santiago, Jevremovic, Johns-Krull, Kashyap, Katsova, Konstantinova-Antova, Kopp, Kunkel, Lang, Lin, López-Santiago, M. J. Fernández-Figueroa, Maggio, Mauas, Mirzoyan, Moffett, Montes, Montes, Montes, Pallavicini, Pallavicini, Pettersen, Pettersen, Pettersen, Pettersen, Pettersen, Phillips, Reale, Robrade, Saar, Sanz-Forcada, Simon, Smith, Spiesman, Sundland, Toner, Torczon, van den Besselaar   +93 more
core   +3 more sources

Optical and near-infrared photometric monitoring of the transient X-ray binary A0538-66 with REM [PDF]

, 2016
The transient Be/X-ray binary A0538-66 shows peculiar X-ray and optical variability. Despite numerous studies, the intrinsic properties underlying its anomalous behaviour remain poorly understood.
Covino, S., Doroshenko, V., Ducci, L., Mereghetti, S., Santangelo, A., Sasaki, M.   +5 more
core   +2 more sources