149 citations · 515 across the 26 of their papers we have counts for
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The October 2022 flare in OJ 287 and the mass of its primary black hole
Mauri J. Valtonen, Staszek Zola, Manpreet Singh +21
The bright blazar OJ~287 has demonstrated a sequence of flares, which are well explained by a quasi-Keplerian orbit model. The flares are associated with the impact of the secondar…
An extremely bright slow-rising afterglow from an off-axis jet in GRB 260310A
Yu-Han Yang, Roberto Ricci, Eleonora Troja +31
We present a multi-wavelength study of GRB 260310A, a nearby long-duration gamma-ray burst at associated with a broad-lined Type Ic supernova. Despite its modest pro…
Identifying the secondary jet in the RadioAstron image of OJ~287
Mauri J. Valtonen, Lankeswar Dey, Staszek Zola +26
The 136 year long optical light curve of OJ~287 is explained by a binary black hole model where the secondary is in a 12 year orbit around the primary. Impacts of the secondary on…
Early steep optical decay linked to reverse shock for GRB200131A
Martin Jelínek, Filip Novotný, Sylvio Klose +3
We observed an optical afterglow of GRB 200131A obtaining the first photometric point 63 s after the satellite trigger. This early observation shows a steep decay, suggesting eithe…
Evidence of jet activity from the secondary black hole in the OJ287 binary system
Mauri J. Valtonen, Staszek Zola, Alok C. Gupta +29
We report the study of a huge optical intraday flare on November 12, 2021, at 2 am UT, in the blazar OJ287. In the binary black hole model it is associated with an impact of the se…
Fires in the deep: The luminosity distribution of early-time gamma-ray-burst afterglows in light of the Gamow Explorer sensitivity requirements
D. A. Kann, N. E. White, G. Ghirlanda +58
Gamma-ray bursts (GRBs) are ideal probes of the Universe at high redshift (z > 5), pinpointing the locations of the earliest star-forming galaxies and providing bright backlights t…
On the need of an ultramassive black hole in OJ 287
Mauri J. Valtonen, Staszek Zola, Achamveedu Gopakumar +25
The highly variable blazar OJ~287 is commonly discussed as an example of a binary black hole system. The 130 year long optical light curve is well explained by a model where the ce…
Observational Implications of OJ 287's Predicted 2022 Disk Impact in the Black Hole Binary Model
Mauri J. Valtonen, Lankeswar Dey, Achamveedu Gopakumar +24
We present a summary of the results of the OJ 287 observational campaign, which was carried out during the 2021/2022 observational season. This season is special in the binary mode…
Refining the 2022 OJ 287 impact flare arrival epoch
Mauri J. Valtonen, Staszek Zola, Gopakumar +24
The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares, which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the…
Prompt emission and early optical afterglow of VHE detected GRB 201015A and GRB 201216C: onset of the external forward shock
Amit Kumar Ror, Rahul Gupta, Martin Jelínek +19
We present a detailed prompt emission and early optical afterglow analysis of the two very high energy (VHE) detected bursts GRB 201015A and GRB 201216C, and their comparison with…
Refining the prediction for OJ 287 next impact flare arrival epoch
Mauri J. Valtonen, Staszek Zola, A. Gopakumar +23
The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the a…
GRB 190919B: Rapid optical rise explained as a flaring activity
Martin Jelínek, Martin Topinka, Sergey Karpov +17
Following the detection of a long GRB 190919B by INTEGRAL (INTErnational Gamma-Ray Astrophysics Laboratory), we obtained an optical photometric sequence of its optical counterpart.…
Exceptionally bright optical emission from a rare and distant ray burst
Gor Oganesyan, Sergey Karpov, Martin Jelínek +19
Long -ray bursts (GRBs) are produced by the dissipation of ultra-relativistic jets launched by newly-born black holes after the collapse of massive stars. Right after the lu…
Looking for fast optical bursts from FRB121102: case study for a small telescopes with sub-second temporal resolution
S. Karpov, M. Jelinek, J. Strobl
To assess the potential of a small telescopes for a high temporal resolution astrophysics, we observed the field of FRB~121102 repeating source of fast radio bursts on a 50-cm D50…
Authenticating the Presence of a Relativistic Massive Black Hole Binary in OJ 287 Using its General Relativity Centenary Flare: Improved Orbital Parameters
Lankeswar Dey, M. J. Valtonen, A. Gopakumar +5
Results from regular monitoring of relativistic compact binaries like PSR 1913+16 are consistent with the dominant (quadrupole) order emission of gravitational waves (GWs). We show…
Stochastic modeling of multiwavelength variability of the classical BL Lac object OJ 287 on timescales ranging from decades to hours
A. Goyal, L. Stawarz, S. Zola +109
We present the results of our power spectral density analysis for the BL Lac object OJ\,287, utilizing the {\it Fermi}-LAT survey at high-energy -rays, {\it Swift}-XRT in X-rays…
A decade of GRB follow-up by BOOTES in Spain (2003-2013)
Martin Jelínek, Alberto J. Castro-Tirado, Ronan Cunniffe +20
This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in the p…
Primary black hole spin in OJ287 as determined by the General Relativity centenary flare
M. J. Valtonen, S. Zola, S. Ciprini +87
OJ287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts which are predictable in a binary black hole model. The model predicted a majo…