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We analyzed Kepler light curves of the blazar W2R 1926+42 that provided nearly continuous coverage from quarter 11 through quarter 17 (589 days between 2011 and 2013) and examined some of their flux variability properties. We investigate…

Astrophysics of Galaxies · Physics 2018-05-01 Yutong Li , Shaoming Hu , Paul J. Wiita , Alok C. Gupta

In this work we search for signatures of low-dimensional chaos in the temporal behavior of the Kepler-field blazar W2R 1946+42. We use a publicly available, ~160000 points long and mostly equally spaced, light curve of W2R 1946+42. We apply…

High Energy Astrophysical Phenomena · Physics 2015-03-18 Rumen Bachev , Banibrata Mukhopadhyay , Anton Strigachev

We study the long term Kepler light curve of the blazar W2R 1926+42 ($\sim$ 1.6 years) which indicates a variety of variability properties during different intervals of observation. The normalized excess variance, $F_{\rm var}$ ranges from…

High Energy Astrophysical Phenomena · Physics 2015-12-23 P. Mohan , Alok C. Gupta , R. Bachev , A. Strigachev

The variability of the high-frequency peaked BL Lac object PKS 2155-304 is studied using almost 10 years of optical, X-ray and gamma-rays data. Publicly available data have been gathered and analyzed with the aim to characterize the…

High Energy Astrophysical Phenomena · Physics 2019-01-16 J. Chevalier , D. A. Sanchez , P. D. Serpico , J. -P. Lenain , G. Maurin

This paper presents light curves and the first systematic characterization of variability of the 106 objects in the Fermi Large Area Telescope (LAT) Bright AGN Sample (LBAS). Weekly light curves obtained during the first 11 months of survey…

High Energy Astrophysical Phenomena · Physics 2015-05-18 A. A. Abdo

Blazars show rapid and violent variabilities, which timescale are often less than a day. We studied intraday variations by applying a shot analysis technique to Kepler monitoring of blazar W2R 1926+42 in Quarter 14. We obtained a mean…

High Energy Astrophysical Phenomena · Physics 2015-02-10 M. Sasada , S. Mineshige , S. Yamada , H. Negoro

PKS 2155-304 is a well studied BL Lac object in the southern sky. The historical optical data during different period have been collected and compiled. Light curves with a time span of 35 years have been constructed. The R-band light curve…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Bing-Kai Zhang , Xiao-Yun Zhao , Chun-Xiao Wang , Ben-Zhong Dai

We present time series analyses of the full Kepler dataset of Zw 229-15. This Kepler light curve --- with a baseline greater than three years, composed of virtually continuous, evenly sampled 30-minute measurements --- is unprecedented in…

High Energy Astrophysical Phenomena · Physics 2014-10-14 Rick Edelson , Simon Vaughan , Matt Malkan , Brandon Kelly , Krista Smith , Padi Boyd , Richard Mushotzky

In an optical monitoring program to characterize the variability properties of blazar, we observed 10 sources from the Roma-BZCAT catalogue for 26 nights in V and R bands during October 2014 to June 2015 with two telescopes located in…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Nibedita Kalita , Alok C. Gupta , Minfeng Gu

We analyze the ${\it Kepler}$ monitoring light curve of a blazar W2R 1926$+$42 to examine features of microvariability by means of the "shot analysis" technique. We select 195 intra-day, flare-like variations (shots) for the continuous…

High Energy Astrophysical Phenomena · Physics 2017-02-01 Mahito Sasada , Shin Mineshige , Shinya Yamada , Hitoshi Negoro

Among active galactic nuclei, blazars show extreme variability properties. We here investigate the case of the BL Lac object S4 0954+65 with data acquired in 2019-2020 by the Transiting Exoplanet Survey Satellite (TESS) and by the Whole…

High Energy Astrophysical Phenomena · Physics 2021-05-12 C. M. Raiteri , M. Villata , V. M. Larionov , S. G. Jorstad , A. P. Marscher , Z. R. Weaver

Optical, near-infrared, and radio observations of the BL Lac object PKS2155-304 were obtained simultaneously with a continuous UV/EUV/X-ray monitoring campaign in 1994 May. Further optical observations were gathered throughout most of 1994.…

In this work, we report the presence of rapid intra-night optical variations in both -- flux and polarization of the blazar BL Lacertae during its unprecedented 2020--2021 high state of brightness. The object showed significant flux…

We study the 1.28 million short cadence {\it Kepler} data points (Q5-Q14) for RR Lyrae covering 24 cycles of the Blazhko variation, and more than one half of the 4-year modulation of the Blazhko variation. This very rich data set clearly…

Solar and Stellar Astrophysics · Physics 2013-10-03 Robert F. Stellingwerf , James M. Nemec , Pawel Moskalik

We present the results of our power spectral analysis for the BL Lac object PKS 0735+178 utilizing the Fermi-LAT survey at high-energy $\gamma$-rays, several ground-based optical telescopes, and single-dish radio telescopes operating at GHz…

High Energy Astrophysical Phenomena · Physics 2017-03-22 Arti Goyal , Lukasz Stawarz , Michal Ostrowski , Valeri Larionov , Gopal-Krishna , Paul J. Wiita , Santosh Joshi , Marian Soida , Ivan Agudo

We present our analysis of the long cadence Kepler data for the well-studied Blazhko star RR Lyr, gathered during the first two quarters of the satellite's observations and covering a total of 127d. Besides being of great importance for our…

Using an unprecedented cadence of 30 minutes provided by the Transiting Exoplanet Survey Satellite (TESS), we have examined the optical light curves (LCs) of the blazar S5 0716+714 obtained from its Sectors 40, 47, and 53 over a period of…

High Energy Astrophysical Phenomena · Physics 2026-03-09 Shubham Kishore , Alok C. Gupta , Paul J. Wiita

We present a first systematic time series study of a sample of blazars observed by the Transiting Exoplanet Survey Satellite $\textit{TESS}$ spacecraft. By cross matching the positions of the sources in the TESS observations with those from…

High Energy Astrophysical Phenomena · Physics 2022-11-23 Vivek Reddy Pininti , Gopal Bhatta , Sagarika Paul , Aman Kumar , Aayushi Rajgor , Rahul Barnwal , Sarvesh Gharat

The results of 8-year R-band photopolarimetric data of blazar Mrk 421 collected from February 2008 to May 2016 are presented, along with extensive multiwavelength observations covering from radio to TeV $\gamma$-rays around the flares…

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