Is Mira B a low mass white dwarf?

ABSTRACT 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 seven nights in the period 2025 August–October, in the course of the last minimum of the Mira pulsations. The observed peak-to-peak amplitude of the flickering is 0.11–0.28mag in B band. For the flickering source we find luminosity in the range $0.10{\!-\!}0.46\,\mathrm{ L}_\odot$. Using the amplitude–flux relation, we estimate an average luminosity of the accretion disc $L_\mathrm{ d} = 0.91 \pm 0.28 \, \mathrm{ L}_\odot$. Assuming that the white dwarf accretes material through Wind Roche Lobe Overflow, we find that Mira B is a low mass white dwarf with $M_{\mathrm{ wd}} = 0.24 \pm 0.04\, \mathrm{ M}_\odot$ accreting at a rate $6.8 \times 10^{-9}\, \mathrm{ M}_\odot$ yr$^{-1}$. This value of the mass is in the range of the extremely low mass white dwarfs. The data are available on Zenodo: https://zenodo.org/records/18756532.