We have performed a study of the influence of the environment on the rate of star formation (SFR) in a sample of galaxies in nearby compact groups. The sample has been chosen from the Catalog of Hickson Compact Groups of Galaxies. High‐quality Hα images of the sample of galaxies in 16 compact groups were obtained and combined with additional deep

An 800 day series of GOLF velocity data, with uniquely high continuity and stability, offers the best ever signal to noise ratio obtained in global Sun observations. Following meticulous efforts to provide reliable calibration, these data have been used for measurements of frequencies, line-widths and power in the p-modes, which are used for

In an attempt to assess the physical realism of the plage flux tube model derived by Bellot Rubio, Ruiz Cobo & Collados (cite{brc}, cite{bellot}) we extend its predictions to the Stokes V zero-crossing shifts of a number of Fe ii lines. For this analysis, accurate Fe ii central wavelengths are required. We have devised a procedure for bringing the

We report the first reliable measurement of the nebular [O i] λ 5577 Angstroms emission line in the Orion nebula. Diagnostic diagrams based on the 5577 [O i], 6300 [O i], 3467 [N i], 5197 [N i], 5200 [N i] emission lines indicate that the bulk of the nebular emission in the partially ionized zone of the Orion nebula is produced in regions with low

The GOLF experiment on board SOHO is designed to measure global oscillations of the disk-integrated sunlight with high sensitivity and with long term stability. The GOLF data is thus ideally suited for both the study of the p-mode spectrum and to address the search for gravity modes. Due to their occasional malfunction the project decided to stop

In order to search for meridional circulation in the solar envelope, we have applied ring diagram analysis to a set of small regions over the surface. The helioseismic data consist of Solar Oscillation Investigation/Michelson Doppler Imager Dopplergrams taken over a time span of about 50 hr (~3000 images) on 1998 June 20-22. The regions studied