Luminosity function of white dwarfs and discovery of new white dwarfs by means of Gaia EDR3 data

The discovery of new White Dwarfs (WDs) is extremely important for understanding the kinematics and dynamics of the local stellar population. They are evolutionary signatures of the Milky Way, as most of stars pass through this evolutionary stage. Gaia’s astrometric accuracy allows more detailed studies of WDs and many other stars. We have constructed the luminosity function for McCook & Sion White Dwarf catalogue objects based on distances provided by Gaia EDR3. We have revealed among 640 First Byurakan Survey UV-excess stars objects with proper motions (PM) >10 mas/yr. Adopting 50 km/s upper limit for tangential velocities, we calculated maximum distances and absolute magnitudes and estimated luminosity types for these objects, revealing 185 probable (M > 8), 69 possible WDs (6 < M < 8) and 42 candidate subdwarfs/WDs. The Digitized First Byurakan Survey (DFBS) is more efficient for discovery of new WDs by spectral energy distribution. Using Gaia data for accurate parallaxes and distances in combination with DFBS low-dispersion spectra and additional multiwavelength data, during the pilot survey we have revealed thousands of new WDs and candidate subdwarf/WDs. Many of them are subject for studies on binarity and variability. Gaia DR3 will provide huge amount of data to confirm these WDs and reveal many more such objects.