We demonstrate that near-infrared CVF spectrometry can be used to determine accurately the spectral type and luminosity class of K- and M-type stars. As an example, we show that the spectral type and luminosity class of the star HR 8881 given in the fourth edition of the Bright Star Catalogue are in error. HR 8881 is an M giant, probably in the

We present in this work the results of a five-month monitoring campaign of the active galactic nucleus in NGC 3227. Both the Balmer H-beta and H-alpha emission lines, as well as the optical continuum have been analyzed. A deblending procedure has been applied which allows for the separation of the contributions to the line emssion from the narrow

Lines with no linear polarization induced by Zeeman effect are unaffected by instrumental polarization. We compile 86 such electric dipole lines with differing temperature and magnetic field sensitivities. In addition, we list 420 spectral lines which produce negligible linear polarization. In most cases, this second set can also be regarded as

As part of a continuing study of the lithium abundances in pre-main sequence (PMS) low mass stars, we present Li observations for 13 K-type and 3 M-type stars belonging to the Pleiades and alpha Persei open clusters, respectively. We have supplemented our measurements with previous data taken from the literature and derived abundances in LTE and

We report high-resolution spectroscopic observations for a sample of 38 T Tauri stars (TTS), complemented by UBVRI photometry of 13 TTS, and CCD VRI photometry for 2 visual binaries. Based on these observations and data taken from the literature, we derive lithium abundances in 53 TTS, concentrating on weak-line TTS (WTTS). The sample spans the

We present results from five nights of pseudo-simulations JHK infrared monitoring of the blazar OJ 287 taken with the Carlos Sanchez Telescope during March 1991 with a time resolution of approximately 20 min. The monitoring shows small amplitude variations in time scales of a few tens of minutes, which are largest in J. Considerable variations are