Context. We present a coherent and detailed Monte Carlo simulation of the population of hot white dwarfs. We assess the statistical significance of the hot end of the white dwarf luminosity function and the role played by the bolometric corrections of hydrogen-rich white dwarfs at high effective temperatures. Aims. We use the most up-to-date stellar evolutionary models and implement a full desc...

Background: Ovarian cancer is the fifth most common cancer in woman and the fifth most frequent cause of cancer death. Ovarian cancers are usually asymptomatic until metastasized, patients have advanced disease at diagnosis in more than 2/3 of the cases. Totally 75-80 % of ovarian masses are benign. The strongest patient related risk factor for ovarian cancer is increasing age. The most ovarian...

Aims. A recent spectroscopic analysis of central stars of planetary nebulae (CSPNe) claims that the sample studied includes five CSPNe with masses very close to the Chandrasekhar limit of white dwarfs. This claim is tested using available kinematical and chemical abundance information. Methods. Kinematical parameters are extracted from Galactic orbits and compared with parameters expected for p...

When the available statistical information is imperfect, it is dangerous to follow standard optimisation procedures to construct an optimal portfolio, which usually leads to a strong concentration of the weights on very few assets. We propose a new way, based on gener-alised entropies, to ensure a minimal degree of diversiication.

We report preliminary results from our search for massive giant planets (6-12 Jupiter masses) around the known seven single white dwarfs in the Hyades cluster at sub-arcsec separations. At an age of 625 Myr, the white dwarfs had progenitor masses of about 3 solar masses, and massive gaseous giant planets should have formed in the massive circumstellar disks around these ex-Herbig A0 stars, prob...

We investigate the sample of 1175 new nonmagnetic DA white dwarfs with the effective temperatures Teff ≥ 12000 K, which were extracted from the Data Release 1 of the Sloan Digital Sky Survey. We determined masses, radii, and bolometric luminosities of stars in the sample. The above parameters were derived from the effective temperatures Teff and surface gravities log g published in the DR1, and...

Strange stars with low masses are suggested to exist in reality, the origin of which could be via accretion-induced collapse (AIC) of white dwarfs. Such a strange star is likely bare, and would thus spin very fast, even to a period of < 0.1 ms. Strange stars with low masses may differ from those with solar-masses in various astrophysical appearances. Observations to test this “low-mass” idea ar...