Aims: We present basic atmospheric parameters (Teff, log g, vt, and [Fe/H]) as well as luminosities, masses, radii, and absolute radial velocities for 348 stars, presumably giants, from the ~1000 star sample observed within the Penn State-Toruń Centre for Astronomy Planet Search with the High Resolution Spectrograph of the 9.2 m Hobby-Eberly

Searches for planets around giants represent an essential complement to 'traditional' surveys, because they furnish information about properties of planetary systems around stars that are the descendants of the A-F main sequence (MS) stars with masses as high as ~5 M⊙. As the stars evolve off the MS, their effective temperatures and rotation rates

M87 has been identified as a displaced supermassive black hole (SMBH) candidate. We investigated this possibility by a temporal analysis of 12 adaptive-optics assisted VLT and HST images spanning 20 yr. We found that the centre of the isophotal fitting to the nuclear region of M87 - assumed to mark the centre of mass of the galaxy - changes

Isolated galaxies are important because they probe the lowest density regimes inhabited by galaxies. We define a sample of 36 nearby isolated early-type galaxies for further study. Our isolation criteria require them to have no comparable-mass neighbours within 2 B-band magnitudes, 0.67 Mpc in the plane of the sky and 700 km s-1 in recession

High-sensitivity measurements of the linearly polarized solar limb spectrum produced by scattering processes in quiet regions of the solar atmosphere showed that the Q/I profile of the lithium doublet at 6708 Å has an amplitude ~10-4 and a curious three-peak structure, qualitatively similar to that found and confirmed by many observers in the Na I

We present long-slit optical spectra along the major axis of the planetary nebula NGC 7009. These data allow us to discuss the physical, excitation, and chemical properties of all the morphological components of the nebula, including its remarkable systems of knots and jets. The main results of this analysis are the following: (1) the electron