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Related papers: Do the Kepler AGN Light Curves Need Re-processing?

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Recent developments in computational power and machine learning techniques motivate their use in many different astrophysical research areas. Consequently, many machine learning models have been trained to classify exoplanet transit signals…

Earth and Planetary Astrophysics · Physics 2025-12-10 Ayan Bin Rafaih , Zachary Murray

We present the results of a blind exercise to test the recoverability of stellar rotation and differential rotation in Kepler light curves. The simulated light curves lasted 1000 days and included activity cycles, Sun-like butterfly…

We present the first results of a high-cadence Swift monitoring campaign ($3-4$ visits per day for $75$ days) of the Seyfert 1.5 galaxy NGC 6814 characterizing its variability throughout the X-ray and UV/optical wavebands. Structure…

High Energy Astrophysical Phenomena · Physics 2023-08-31 Adam G. Gonzalez , Luigi C. Gallo , Jon M. Miller , Elias S. Kammoun , Akshay Ghosh , Ben A. Pottie

We present detailed multi-wavelength observations of GRB 161219B at $z=0.1475$, spanning the radio to X-ray regimes, and the first ALMA light curve of a GRB afterglow. The cm- and mm-band observations before $8.5$ d require emission in…

This work develops application techniques for stochastic modelling of Active Galactic Nuclei (AGN) variability as a probe of accretion disk physics. Stochastic models, specifically Continuous Auto-Regressive Moving Average (CARMA) models,…

Instrumentation and Methods for Astrophysics · Physics 2019-09-06 Jackeline Moreno , Michael S. Vogeley , Gordon T. Richards

Recent observations have shown that the Fe Kalpha line profile of the Seyfert~1 galaxy MCG-06-30-15 is strongly variable. We attempt accretion disk model fits to the Fa Kalpha line profiles in a high, low and medium continuum luminosity…

Astrophysics · Physics 2015-06-24 J. W. Sulentic , P. Marziani , M. Calvani

AGNs are known to be variable in almost all wavelengths and timescales. The shortest variability timescale of AGNs can be used to probe the smallest scale structures within AGNs. We aim to measure the shortest detected variability…

Astrophysics of Galaxies · Physics 2026-05-13 Heechan Yuk , Xinyu Dai , Natalie Kovacevic

Time-domain surveys have advanced astronomical research by revealing diverse variable phenomena, from stellar flares to transient events. The scale and complexity of survey data, along with the demand for rapid classification, present…

Instrumentation and Methods for Astrophysics · Physics 2025-12-10 Xiaoxiong Zuo , Yihan Tao , Yang Huang , Zhixuan Kang , Huaxi Chen , Chenzhou Cui , Jiashu Pan , Xiao Kong , Xiaoyu Tang , Henggeng Han , Haiyang Mu , Yunfei Xu , Dongwei Fan , Guirong Xue , Ali Luo , Jifeng Liu

It has been demonstrated that the time variability of a star's brightness at different frequencies can be used to infer its surface gravity, radius, mass, and age. With large samples of light curves now available from Kepler and K2, and…

Solar and Stellar Astrophysics · Physics 2018-10-17 Melissa K. Ness , Victor Silva Aguirre , Mikkel N. Lund , Matteo Cantiello , Daniel Foreman-Mackey , David W. Hogg , Ruth Angus

We provide an overview of stellar variability in the first quarter of data from the Kepler mission. The intent of this paper is to examine the entire sample of over 150,000 target stars for periodic behavior in their lightcurves, and relate…

(Abridged) We present an analysis of a 10-day continuous ASCA observation of the narrow-line Seyfert 1 galaxy IRAS 13224-3809. The soft (0.7-1.3 keV) and hard (1.3-10 keV) X-ray band light curves binned to 5000s reveal trough-to-peak…

Astrophysics · Physics 2009-11-07 G. C. Dewangan , Th. Boller , K. P. Singh , K. M. Leighly

Double-peaked \oiii~profiles could potentially indicate kiloparsec-scale dual AGNs. We analyze long-term optical light curves of 35 type 1 AGNs with such features from our recent catalog in Zheng et al. (2025). These light curves are…

Astrophysics of Galaxies · Physics 2025-08-04 Qi Zheng , Xingyv Zhu , Xueguang Zhang , Qirong Yuan

We report the discovery that the known `changing look' AGN Mrk 1018 has changed spectral type for a second time. New VLT-MUSE data taken in 2015 as part of the Close AGN Reference Survey (CARS) shows that the AGN has returned to its…

We observed two full orbital phase curves of the transiting brown dwarf KELT-1b, at 3.6um and 4.5um, using the Spitzer Space Telescope. Combined with previous eclipse data from Beatty et al. (2014), we strongly detect KELT-1b's phase…

Earth and Planetary Astrophysics · Physics 2019-10-09 Thomas G. Beatty , Mark S. Marley , B. Scott Gaudi , Knicole D. Colon , Jonathan J. Fortney , Adam P. Showman

We present the first Kepler monitoring of a strongly variable BL Lac, W2R1926+42. The light curve covers 181 days with ~0.2% errors, 30 minute sampling and >90% duty cycle, showing numerous delta I/I > 25% flares over timescales as short as…

High Energy Astrophysical Phenomena · Physics 2014-09-08 R. Edelson , R. Mushotzky , S. Vaughan , J. Scargle , P. Gandhi , M. Malkan , W. Baumgartner

Data from the first three years of RXTE observations have been systematically analyzed to yield a set of 300 day, 2-10 keV light curves with similarly uniform, ~5 day sampling, for a total of nine Seyfert 1 galaxies. This is the first X-ray…

Astrophysics · Physics 2009-10-31 A. Markowitz , R. Edelson

Ground-based photometric observations from WASP have been calibrated, scaled and combined with Kepler observations of the $\delta$ Sct star KIC 7106205, allowing us to extend the time base of the study of the unexplained amplitude and…

Solar and Stellar Astrophysics · Physics 2015-06-23 Dominic M. Bowman , Daniel L. Holdsworth , Donald W. Kurtz

Light curve modulations in the sample of Kepler planet candidates allows the disentangling of the nature of the transiting object by photometrically measuring its mass. This is possible by detecting the effects of the gravitational pull of…

Earth and Planetary Astrophysics · Physics 2016-07-20 J. Lillo-Box , A. Ribas , D. Barrado , B. Merín , H. Bouy

Analysis and interpretation of the Her X-1 X-ray light curve obtained with the ASM onbord RXTE over the period 1996 February to 2004 September is presented. We report that the features found previously in the averaged X-ray lightcurve are…

Astrophysics · Physics 2007-11-12 D. Klochkov , N. Shakura , K. Postnov , R. Staubert , J. Wilms , N. Ketsaris

We present 16 new, and confirm 7 previously identified, DA white dwarfs in the Kepler field through ground-based spectroscopy with the Hale 200", Kitt Peak 4-meter, and Bok 2.3-meter telescopes. Using atmospheric models we determine their…

Solar and Stellar Astrophysics · Physics 2016-10-18 T. F. Doyle , S. B. Howell , V. Petit , S. Lepine
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