21 papers
Multi-band optical photometric variability of the blazar OJ 287 from 2015 to 2025
Alok C. Gupta, Karan Dogra, Mark Kidger +101
We present the most densely sampled multi-band optical photometric observations of the peculiar BL Lacertae object OJ 287 from 2015 to 2025 with a focus on its optical activity on…
Isochrone Fitting of Galactic Globular Clusters -- VIII. Homogeneous estimates of parameters for 27 clusters
G. A. Gontcharov, O. S. Ryutina, C. J. Bonatto +2
We use the Stetson, HST, and Gaia DR3 data sets for 22 Galactic globular clusters to select their members and fit their CMDs with isochrones from DSED and BaSTI for Fe$]=+0.4…
Tracking down the broadband polarimetric properties of PG 1553+113
Riccardo Middei, Svetlana G. Jorstad, Alan P. Marscher +78
We report on a nine-month monitoring campaign of the blazar PG 1553+113, relying on three observations carried out in 2025 with the Imaging X-ray Polarimetry Explorer (IXPE) and su…
First detection of VHE gamma-ray signal from the FSRQ TON 0599
MAGIC Collaboration, K. Abe, S. Abe +245
TON\,0599 (z=0.7247) belongs to the few flat spectrum radio quasars (FSRQs) detected in the very high energy (VHE, \,GeV) gamma-ray band. Its redshift makes it currently o…
Multiwavelength quasi-periodic variability of the blazar Ton 599
Yu. V. Sotnikova, T. V. Mufakharov, A. E. Volvach +34
During the last 40-50 years, the TeV blazar Ton 599 has systematically experienced major outbursts detected in a wide wavelength range from radio to -rays. In this work, we pre…
Isochrone Fitting of Galactic Globular Clusters -- VII. NGC1904 (M79), NGC4372, and revision of NGC288, NGC362, NGC5904 (M5), NGC6205 (M13), and NGC6218 (M12)
George A. Gontcharov, Sergey S. Savchenko, Olga S. Ryutina +8
We estimate key parameters for the Galactic globular clusters NGC1904 and NGC4372 and update the parameters for NGC288, NGC362, NGC5904, NGC6205, and NGC6218, which were analysed i…