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B. Borisov

Publications and source records attributed to B. Borisov.

2 recordsLinked to original sources

Is Mira B a low mass white dwarf?

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 the period August - October 2025, in the course of the last minimum of the Mira pulsations. The observed peak-to-peak amplitude of the flickering is 0.11-0.28 mag in B band. For the flickering source we find luminosity in the range 0.10-0.46 L_sun. Using the amplitude-flux relation, we estimate an average luminosity of the accretion disc L_d = 0.91 +/- 0.28 L_sun. Assuming that the white dwarf accretes material through Wind Roche Lobe Overflow (WRLOF), we find that Mira B is a low mass white dwarf with M_wd = 0.24 +/- 0.04 M_sun accreting at a rate 6.8x10^{-9} M_sun/yr. This value of the mass is in the range of the extremely low mass white dwarfs. The data are available on Zenodo: zenodo.org/records/18756532

astro-ph.SR

The hidden symbiotic star SU Lyn -- detection of flickering in U band

We report photometric observations of the hidden symbiotic star SU Lyn in the optical bands. In five nights we detect a weak flickering in U band with amplitude of about 0.05 magnitudes. No intranight variations are found in B, V, g' and r' bands. This is one more indication that the secondary component is a white dwarf accreting at low accretion rate. We also searched for intranight variability of a dozen related object (RR Boo, RT Boo, AM Cyg, AG Peg, BF Cyg, NQ Gem, StHa190, V627 Cas, XX Oph, FS Cet and Y Gem) in which no variability above the observational errors is detected.

astro-ph.SR