In 1995 we commenced a detailed spectral and photometric study of Shakhbazian compact groups. In this paper the results on groups ShCG 181, ShCG 344, ShCG 361, and ShCG 362 are presented. The redshifts of member galaxies in groups and the radial velocity dispersions, the results of the surface photometry in BVR, the profiles of the surface

We have used CCD imaging polarimetry to obtain linear polarization measurements of background stars toward the filamentary Musca dark cloud. We present a catalog of 2497 objects with polarization signal-to-noise ratio larger than 5. This allows us to build polarization maps to infer the detailed geometry of the local magnetic field. We show

We investigate the feasibility of measuring line-of-sight magnetic field strength in the solar chromosphere through Stokes polarimetry in the hydrogen Hα line. Because of the large intrinsic Doppler width of the hydrogen line, the weak-field approximation applies even for the strongest magnetic fields in the solar atmosphere. We calculate the Hα

Since pulsating subdwarf B (sdBV or EC14026) stars were first discovered, observational efforts have tried to realize their potential for constraining the interior physics of extreme horizontal branch stars. Difficulties encountered along the way include uncertain mode identifications and a lack of stable pulsation mode properties. Here we report

Using classical model atmospheres and an LTE analysis, Mg isotope ratios 24Mg:25Mg:26Mg are measured in 32 Hyades dwarfs covering effective temperatures 4000K

This paper is focused on the search for low-amplitude solar gravity modes between 150 and 400 μHz, corresponding to low-degree, low-order modes. It presents results based on an original strategy that looks for multiplets instead of single peaks, taking into consideration our knowledge of the solar interior from acoustic modes. Five years of quasi