H-alpha observations of the recurrent nova T CrB
ATel #17075; M. Hristova, S. Kandzhichka (TU Sofia), V. Marchev, R. Zamanov, K. Stoyanov (Bulgarian Academy of Sciences), D. Marchev (Shumen University)
on 11 Mar 2025; 11:18 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Kiril Stoyanov (kstoyanov@astro.bas.bg)
Subjects: Optical, Binary, Cataclysmic Variable
Referred to by ATel #: 17110
We performed spectral observations of the recurrent nova T Coronae Borealis with the Echelle spectrograph at the 2m RCC telescope (Bonev et al. 2017, Bulgar. Astron. J., 26, 67) of the Rozhen National Astronomical Observatory, Bulgaria:
Date-obs exposure EW(H-alpha) [Å]
2024-08-21T19:30 60 min 11.9 +/- 0.6
2024-08-22T20:23 60 min 11.2 +/- 0.6
2025-01-18T03:20 30min+45min 12.5 +/- 0.6
2025-03-09T23:10 45min+45min 21.8 +/- 1.0
On the spectrum obtained on 9/10 March 2025, we measure equivalent width of H-alpha emission line 21.8 angstroms. This means that the equivalent width of H-alpha emission line increased by factor of 2 in comparison with the observations in August 2024 and January 2025 (thus confirm the finding in ATel#17041). The emission line is asymmetric with violet-to-red peak ratio 0.63 +/- 0.01, which probably means that the accretion disc is eccentric. The emission line is double peaked with distance between the peaks 91 +/-1 km/s, which corresponds to a disc radius 107 R_sun, which means that the disc extends almost to the inner Lagrangian point L_1.
Evolution of the H-alpha emission line of T CrB
