Recent UB photometry of T CrB
ATel #17052; G. Yordanova, D. Marchev, B. Borisov, T. Atanasova-Sartliiska (Shumen University), V. Marchev, R. Zamanov (Bulgarian Academy of Scienses)
on 26 Feb 2025; 12:24 UT
Credential Certification: Vladislav Marchev (vlad.marchev@gmail.com)
Subjects: Optical, Cataclysmic Variable, Variables
We present recent U and B filter photometric data of the symbiotic recurrent Nova T CrB from two nights- 22/23 February and 24/25 February 2025 and compare to previous observations from the same telescope collected on the 8th of April 2024. Observations were conducted with 40 cm MEADE LX200ACF telescope and a CCD camera FLI PL09000 with a filed of view: 31x31 arcmin and resolution: 0.61 arcsec/pixel at the observatory of the Shumen University "Episkop Konstantin Preslavski".
The observations were performed in a 3.5 hour time frame during both nights with 60 exposures for both filters U and B, and respective exposure time 120s and 40s.
For the first night (22.02.2025) we observe an average magnitude in U=10.626+/-0.008 and in B=11.170+/-0.005 with an amplitude of the flickering 0.360 in U and 0.199 in B.
For the second night (24.02.2025) we observe an average magnitude in U=10.795+/-0.010 and in B=11.178+/-0.005 with an amplitude of the flickering 0.272 in U and 0.139 in B.
Comparing these results with previous observations from April last year with the same telescope, we see a significant increase in the overall brightness in U accompanied with consistent flickering in the same band: U=12.022+/-0.023 and in B=11.404+/-0.004 with an amplitude of the flickering 0.417 in U and 0.068 in B.
The observed increase of around 1 mag in U can be explained with the overall increased activity of T CrB mentioned in ATel #17030 and ATel #17041, where the authors have noticed enhancement in the intensity and the width of the H\u03b1 and Helium emission lines and have attributed it to a potential increase in the accretion rate or expansion of the accretion disc.
Acknowledgments: project RD-08-95/2025 FSR Shumen University.
Recent UBV Photometry of T CrB
