Results 1 to 10 of about 2,370 (148)

Radio and Optical Flares on the dMe Flare Star EV Lac

The Astrophysical Journal
We present the results of a coordinated campaign to observe radio and optical stellar flares from the nearby M dwarf flare star EV Lac. From a total of 27 hr of radio and 29 hr of optical observations, we examine the correspondence of the action of ...
Rachel A. Osten, Adam F. Kowalski, Suzanne Hawley, Isaiah I. Tristan, Sarah J. Schmidt, Ben Tofflemire, Eric Hilton   +6 more
doaj   +3 more sources

GAMMA-RAY BURST FLARES: ULTRAVIOLET/OPTICAL FLARING. I. [PDF]

The Astrophysical Journal, 2013
We present a previously unused method for the detection of flares in gamma-ray burst (GRB) light curves and use this method to detect flares in the ultraviolet/optical. The algorithm makes use of the Bayesian Information Criterion to analyze the residuals of the fitted light curve, removing all major features, and to determine the statistically best ...
Swenson, C. A., Roming, P. W. A., De Pasquale, M., Oates, S. R.   +3 more
openaire   +2 more sources

Constraints on Stellar Flare Energy Ratios in the NUV and Optical from a Multiwavelength Study of GALEX and Kepler Flare Stars

The Astrophysical Journal, 2023
We present a multiwavelength study of stellar flares on primarily G-type stars using overlapping time domain surveys in the near-ultraviolet (NUV) and optical regimes. The NUV (the Galaxy Evolution Explorer; GALEX) and optical (Kepler) wavelength domains
C. E. Brasseur, Rachel A. Osten, Isaiah I. Tristan, Adam F. Kowalski   +3 more
doaj   +1 more source

Minutes-duration optical flares with supernova luminosities

Nature, 2023
In recent years, certain luminous extragalactic optical transients have been observed to last only a few days. Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae) whose timescale is weeks.
Ho, A.Y.Q., Perley, D.A., Chen, P., Schulze, S., Dhillon, V., Kumar, H., Suresh, A., Swain, V., Bremer, M., Smartt, S.J., Anderson, J.P., Anupama, G.C., Awiphan, S., Barway, S., Bellm, E.C., Ben-Ami, S., Bhalerao, V., de Boer, T., Brink, T.G., Burruss, R., Chandra, P., Chen, T.-W., Chen, W.-P., Cooke, J., Coughlin, M.W., Das, K.K., Drake, A.J., Filippenko, A.V., Freeburn, J., Fremling, C., Fulton, M.D., Gal-Yam, A., Galbany, L., Gao, H., Graham, M.J., Gromadzki, M., Gutiérrez, C.P., Hinds, K.-R., Inserra, C., A J, N., Karambelkar, V., Kasliwal, M.M., Kulkarni, S., Müller-Bravo, T.E., Magnier, E.A., Mahabal, A.A., Moore, T., Ngeow, C.-C., Nicholl, M., Ofek, E.O., Omand, C.M.B., Onori, F., Pan, Y.-C., Pessi, P.J., Petitpas, G., Polishook, D., Poshyachinda, S., Pursiainen, M., Riddle, R., Rodriguez, A.C., Rusholme, B., Segre, E., Sharma, Y., Smith, K.W., Sollerman, J., Srivastav, S., Strotjohann, N.L., Suhr, M., Svinkin, D., Wang, Y., Wiseman, P., Wold, A., Yang, S., Yang, Y., Yao, Y., Young, D.R., Zheng, W.   +76 more
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LOW-POWER SOLAR FLARES OF OPTICAL AND X-RAY WAVELENGTHS FOR SOLAR CYCLES 21–24

Solar-Terrestrial Physics, 2020
Using data obtained in optical and X-ray wavelengths, we have analyzed solar flare activity for cycles 21–24. Over the last three cycles, solar activity is shown to decrease significantly.
A.V. Borovik , A.A. Zhdanov
doaj   +1 more source

Chandra, HST/STIS, NICER, Swift, and TESS Detail the Flare Evolution of the Repeating Nuclear Transient ASASSN -14ko

The Astrophysical Journal, 2023
ASASSN-14ko is a nuclear transient at the center of the AGN ESO 253−G003 that undergoes periodic flares. Optical flares were first observed in 2014 by the All-Sky Automated Survey for Supernovae (ASAS-SN) and their peak times are well-modeled with a ...
Anna V. Payne, Katie Auchettl, Benjamin J. Shappee, Christopher S. Kochanek, Patricia T. Boyd, Thomas W.-S. Holoien, Michael M. Fausnaugh, Chris Ashall, Jason T. Hinkle, Patrick J. Vallely, K. Z. Stanek, Todd A. Thompson   +11 more
doaj   +1 more source

Dynamics of small-scale magnetic fields before small and large solar flares

Solar-Terrestrial Physics, 2023
We have examined the dynamics of the longitudinal magnetic field of active region NOAA 12673, using data from the Solar Dynamics Observatory (SDO). During the passage of the active region (AR) across the solar disk, its spots and background fields showed
Borovik A. V., Zhdanov A. A.
doaj   +1 more source

Catching profound optical flares in blazars

Monthly Notices of the Royal Astronomical Society, 2023
ABSTRACT Flaring episodes in blazars represent one of the most violent processes observed in extra-galactic objects. Studies of such events shed light on the energetics of the physical processes occurring in the innermost regions of blazars, which cannot otherwise be resolved by any current instruments.
Gopal Bhatta, Staszek Zola, M Drozdz, Daniel Reichart, Joshua Haislip, Vladimir Kouprianov, Katsura Matsumoto, Eda Sonbas, D Caton, Urszula Pajdosz-Śmierciak, A Simon, J Provencal, Dariusz Góra, Grzegorz Stachowski   +13 more
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X-Ray, Near-ultraviolet, and Optical Flares Produced by Colliding Magnetospheres in the Young High-eccentricity Binary DQ Tau

The Astrophysical Journal, 2023
DQ Tau is a unique young high-eccentricity binary system that exhibits regular magnetic reconnection flares and pulsed accretion near periastron. We conducted NuSTAR, Swift, and Chandra observations during the 2022 July 30 periastron to characterize X ...
Konstantin V. Getman, Ágnes Kóspál, Nicole Arulanantham, Dmitry A. Semenov, Grigorii V. Smirnov-Pinchukov, Sierk E. van Terwisga   +5 more
doaj   +1 more source

OPTICAL DISCOVERY OF PROBABLE STELLAR TIDAL DISRUPTION FLARES [PDF]

The Astrophysical Journal, 2011
Using archival SDSS multi-epoch imaging data (Stripe 82), we have searched for the tidal disruption of stars by super-massive black holes in non-active galaxies. Two candidate tidal disruption events (TDEs) are identified. They have optical black-body temperatures 2 10^4 K and observed peak luminosities M_g=-18.3 and -20.4; their cooling rates are very
van Velzen, Sjoert, Farrar, Glennys R., Gezari, Suvi, Morrell, Nidia, Zaritsky, Dennis, Östman, Linda, Smith, Mathew, Gelfand, Joseph, Drake, Andrew J.   +8 more
openaire   +5 more sources