activity
20232026
most citedOptical variability of the blazar 3C 371: from minute to year timescales

13 citations · 20 across the 6 of their papers we have counts for

collaborators

6 papers

astro-ph.SR2026

Is Mira B a low mass white dwarf?

R. K. Zamanov, V. Irincheva, B. Spassov +8

We report photometric observations in Johnson B and V bands of the short term variability (flickering) of Mira (omicron Ceti). The observations were performed during 7 nights in th…

astro-ph.HE2025

A New Phase of Optical Activity of BL Lacertae in the Fall of 2024: Intra-Night Flux and Polarization Variations

Rumen Bachev, Milen Minev, Anton Strigachev +1

BL Lacertae is not only archetypical of an entire class of jet-dominated active galactic nuclei, blazars, but also one of the most active and rapidly changing objects in this class…

astro-ph.HE2025

Optical Photometric Monitoring of the Blazar OT 355 and Local Standard Stars' Calibration

R. Bachev, Tushar Tripathi, Alok C. Gupta +11

OT 355 (4FGL J1734.3 + 3858) is a relatively rarely studied but highly variable, moderate-redshift (z = 0.975) flat-spectrum radio quasar (blazar). With this work, we aim to study…

astro-ph.SR2024★ 3 cited

Evolution of the optical emission lines and the X-ray emission during the super-active stage of T CrB

K. A. Stoyanov, G. J. M. Luna, R. K. Zamanov +6

T CrB is a symbiotic star that experiences nova outbursts every 80~yr. The next, long-anticipated nova outburst should occur during the 2024-2026 period. Here, we present re…

astro-ph.HE2024★ 13 cited

Optical variability of the blazar 3C 371: from minute to year timescales

J. Otero-Santos, C. M. Raiteri, J. A. Acosta-Pulido +41

The BL Lac object 3C 371 has been observed by the Transiting Exoplanet Survey Satellite (\textit{TESS}) for approximately a year, between July 2019 and July 2020, with an unmatched…

astro-ph.SR2023★ 4 cited

Optical spectroscopy of Be stars: peak separation of Balmer emission lines

R. K. Zamanov, K. A. Stoyanov, S. Y. Stefanov +2

The Be stars display variable optical emission lines originating in the circumstellar disc. Here we analyse high resolution spectroscopic observations of Be stars and the distance…