12 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…
Comprehensive Analysis of Optical brightness and Color Variability of Blazars in the ZTF Survey DR22
Qi Yuan, Xin Wang, Meng Zhang +6
This study conducts a comprehensive analysis of brightness and color variability in blazars, utilizing over six years of quasi-simultaneous g-band and r-band data from 1149 sources…
The Intermediate-Mass Black Hole Reverberation Mapping Project: Stable Optical Continuum Lags of an IMBH in the Dwarf Galaxy NGC 4395 Over Years
Yu Pan, Hengxiao Guo, Chenxu Liu +15
NGC 4395 is a nearby dwarf spiral galaxy hosting an active galactic nucleus (AGN) powered by an intermediate-mass black hole (IMBH, --). Re…
Detection of optical quasi-periodic oscillation in the blazar 3C 454.3
Karan Dogra, Alok C. Gupta, C. M. Raiteri +83
We analyzed 19 years of -band data of the blazar 3C 454.3 from the Whole Earth Blazar Telescope (WEBT) archive, along with new data from its members and from public archives suc…
A systematic evaluation of vision-language models for observational astronomical reasoning tasks
Wenke Ren, Hengxiao Guo, Wenwen Zuo +1
Vision-language models (VLMs) are increasingly proposed as general-purpose tools for scientific data interpretation, yet their reliability on real astronomical observations across…
Evidence for a Delayed UV Counterpart to X-ray Quasi-periodic Eruptions in Ansky
Hengxiao Guo, Zhen Yan, Ya-Ping Li +15
X-ray quasi-periodic eruptions (QPEs) represent a novel population of extreme, repeating nuclear transients whose physical origins remain debated. A defining characteristic of QPEs…