We study combinatorial configurations with the associated point and line graphs being strongly regular. Examples not belonging to known classes such as partial geometries their generalizations or elliptic semiplanes are constructed. Necessary existence conditions proved a table of feasible parameters at most 200 points is presented. Non-existence some proved.

virial theorem is important for understanding stellar structures. it produces an interesting connection between magnetic and gravitational energies. using the general form of the virial theorem including the magnetic field (toroidal magnetic field), we may explain the solar dynamo model in relation to variations of the magnetic and gravitational energies. we emphasize the role of the gravitatio...

We derive stellar metallicities, light-weighted ages and stellar masses for a magnitudelimited sample of 175,128 galaxies drawn from the Sloan Digital Sky Survey Data Release Two (SDSS DR2). We compute median-likelihood estimates of these parameters using a large library of model spectra at medium-high resolution, covering a comprehensive range of star formation histories. The constraints we de...

Accuracies reached in space astrometry now permit the accurate determination of astrometric radial velocities, without any use of spectroscopy. Knowing this true stellar motion, spectral shifts intrinsic to stellar atmospheres can be identified, for instance gravitational redshifts and those caused by velocity fields on stellar surfaces. The astrometric accuracy is independent of any spectral c...

Abstract The amplification of magnetic fields plays an important role in explaining numerous astrophysical phenomena associated with binary neutron star mergers, such as mass ejection and the powering short gamma-ray bursts. Magnetic isolated stars are often assumed to be confined a small region near stellar surface, while they normally taken fill whole numerical modeling mergers. By performing...