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Stability valley for strange dwarfs

Vartanyan, Yu. L.; Hajyan, G. S.; Grigoryan, A. K. +1 more

This is a study of the stability of strange dwarfs, superdense stars with a small self-confining core (M_core < 0.02 M_⊙) containing strange quark matter and an extended crust consisting of atomic nuclei and degenerate electron gas. The mass and radius of these stars are of the same orders as those of ordinary white dwarfs. …

Effect of hot jupiters on the variability of stellar radiation

Arkharov, A. A.; Ruban, E. V.

The effect of hot jupiters on the variability of light from 14 bright stars with planets that are listed in the Pulkovo Spectrophotometric Catalog (PSC) and the Hipparcos photometric catalog is studied. The spectral range 320-1080 nm and the Vt and Bt photometric magnitudes are examined. The photometric observations reveal microvariability of the …

Young stars in gas-dust disks. I. Fomalhaut

Arkharov, A. A.; Ruban, E. V.

This is a single-factor analysis of the variance of the average quasimonochromatic magnitudes of Fomalhaut, α PsA, in the 325-1080 nm spectral range for different observation seasons collected in the Pulkovo Spectrophotometric Data Base (PSDB). The overall variance of the data combined over several seasons is decomposed into components characteriz…

Young stars in gas-dust disks. II. Vega (α Lyr) and β Pic

Arkharov, A. A.; Ruban, E. V.

Observational data for Vega, α Lyr in the 325-1080 nm range from various years are studied using material stored at the Pulkovo Spectrophotometric Data Base (PSDB). It is shown that the spectrophotometric temperature of the star was lower than the effective temperature according to data from all the observational seasons. Possible reasons for this…