149 citations · 798 across the 34 of their papers we have counts for
34 papers
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…
Size, shape, density, and atmospheric limit of (50000) Quaoar revealed from 14 years of stellar occultation
Giuliano Margoti, Felipe Braga-Ribas, José Luis Ortiz +173
We present results from 28 stellar occultations by the large Trans-Neptunian Object (50000) Quaoar registered between 2018 and 2025. By performing a joint analysis of this occultat…
The spin state of asteroid Apophis and a prediction of its change during the 2029 close encounter with Earth
J. Durech, D. Vokrouhlicky, P. Pravec +23
On April 13, 2029, the asteroid Apophis will pass near Earth at a geocentric distance of about 38,000 km. Numerical models have suggested that the post-encounter spin state will cr…
Gaia20fnr: A binary-lens microlensing event with full orbital motion revealed by four space telescopes
M. Wicker, Ł. Wyrzykowski, M. Hundertmark +49
The microlensing event Gaia20fnr is a long-duration, non-caustic-crossing binary-lens event at high Galactic latitude. Triggered by a photometric rise detected by the Gaia space mi…
The Progenitor of the Type II-Plateau SN 2025pht in NGC 1637: The Dustiest, Most Luminous Red Supergiant So Far?
Schuyler D. Van Dyk, Tamas Szalai, Gagandeep S. Anand +14
We provide a characterization of the red supergiant (RSG) progenitor candidate for the nearby Type II-plateau supernova (SN) 2025pht in NGC 1637. The star was first detectable in 2…
ExoClock Project IV: A homogeneous catalogue of 620 updated exoplanet ephemerides
A. Kokori, A. Tsiaras, G. Pantelidou +323
The ExoClock project is an open platform aiming to monitor exoplanets by integrating observations from space and ground based telescopes. This study presents an updated catalogue o…
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…
ASASSN-24fw: Candidate circumplanetary disk occultation of a main-sequence star
Nadia L. Zakamska, Gautham Adamane Pallathadka, Dmitry Bizyaev +24
Dusty disks around planetary and substellar companions in outer reaches of exo-planetary systems can be detected as long-lasting occultations, provided the observer is close to the…
Asteroid sizes determined with thermophysical model and stellar occultations
A. Choukroun, A. Marciniak, J. Ďurech +165
Context. The sizes of many asteroids, especially slowly rotating, low-amplitude targets, remain poorly constrained due to selection effects. These biases limit the availability of…
Constraining Lens Masses in Moderately to Highly Magnified Microlensing Events from Gaia
U. Pylypenko, Ł. Wyrzykowski, P. J. Mikołajczyk +57
Microlensing events provide a unique way to detect and measure the masses of isolated, non-luminous objects, particularly dark stellar remnants. Under certain conditions, it is pos…
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…
Lens mass estimate in the Galactic disk extreme parallax microlensing event Gaia19dke
M. Maskoliūnas, Ł. Wyrzykowski, K. Howil +74
We present the results of our analysis of Gaia19dke, an extraordinary microlensing event in the Cygnus constellation that was first spotted by the {\gaia} satellite. This event fea…
Gaia22dkvLb: A Microlensing Planet Potentially Accessible to Radial-Velocity Characterization
Zexuan Wu, Subo Dong, Tuan Yi +50
We report discovering an exoplanet from following up a microlensing event alerted by Gaia. The event Gaia22dkv is toward a disk source rather than the traditional bulge microlensin…
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…
The Gaia alerted fading of the FUor-type star Gaia21elv
Zsófia Nagy, Sunkyung Park, Péter Ábrahám +26
FU Orionis objects (FUors) are eruptive young stars, which exhibit outbursts that last from decades to a century. Due to the duration of their outbursts, and to the fact that only…
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…
The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets
Samuel W. Yee, Joshua N. Winn, Joel D. Hartman +83
NASA's Transiting Exoplanet Survey Satellite (TESS) mission promises to improve our understanding of hot Jupiters by providing an all-sky, magnitude-limited sample of transiting ho…
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…
Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation
P. Santos-Sanz, J. L. Ortiz, B. Sicardy +85
Within our international program to obtain accurate physical properties of trans-Neptunian objects (TNOs) we predicted a stellar occultation by the TNO (38628) Huya of the star Gai…
Refinement of the convex shape model and tumbling spin state of (99942) Apophis using the 2020-2021 apparition data
H. -J. Lee, M. -J. Kim, A. Marciniak +30
Context. The close approach of the near-Earth asteroid (99942) Apophis to Earth in 2029 will provide a unique opportunity to examine how the physical properties of the asteroid cou…
Probing Transit Timing Variations of Three Hot-Jupiters: HATP-36b, HATP-56b, and WASP-52b
E. Sonbas, N. Karaman, A. Özdönmez +5
We report the results of new transit observations for the three hot Jupiter-like planets HATP-36b, HATP-56b and WASP-52b respectively. Transit timing variations (TTVs) are presente…
Properties of slowly rotating asteroids from the Convex Inversion Thermophysical Model
A. Marciniak, J. Ďurech, V. Alí-Lagoa +73
Results from the TESS mission showed that previous studies strngly underestimated the number of slow rotators, revealing the importance of studying those asteroids. For most slowly…
RoboPol: AGN polarimetric monitoring data
D. Blinov, S. Kiehlmann, V. Pavlidou +29
We present uniformly reprocessed and re-calibrated data from the RoboPol programme of optopolarimetric monitoring of active galactic nuclei (AGN), covering observations between 201…