Sampling fluctuations in stellar populations give rise to dispersion in observables when a small number of sources contribute effectively to the observables. This is the case for a variety of linear functions of the spectral energy distribution (SED) in small stellar systems, such as galactic and extragalactic HII regions, dwarf galaxies or stellar

GLMP 621 (IRAS 17395-0841) was first identified as a possible new planetary nebula on the basis of its IRAS colors (García-Lario et al. 1997). A few years ago it was confirmed as such through spectroscopic observations where nebular emission lines corresponding to a prototypical low-excitation planetary nebula were detected superimposed on a strong

Using H alpha emission line profiles we detect outflowing ionized gas at velocities of order 50 km/s from representative luminous H II regions in two sample disk galaxies, NGC 3359 and NGC 1530, and calculate the physical parameters of the outflowing material.

Numerical simulations of kinematic dynamo action in steady and three-dimensional ABC flows are presented with special focus on the difference in growth rates between cases with single and multiple periods of the prescribed velocity field. It is found that the difference in growth rate (apart from a trivial factor stemming from a scaling of the rate

A near- and mid-infrared study of the star-formation complex G 9.62+0.19 is presented. dIt includes photometrically calibrated images through wide-band JHK and narrow-band Br gamma , H[2], and 12.5 mu m filters. The observations were made at Las Campanas, La Silla and the Observatorio Astronómico Nacional-San Pedro Mártir observatories.

We present surface photometry and stellar kinematics of a sample of five SB0 galaxies: ESO 139-G009, IC 874, NGC 1308, NGC 1440 and NGC 3412. We measured their bar pattern speed using the Tremaine-Weinberg method, and derived the ratio, , of the corotation radius to the length of the bar semimajor axis. For all the galaxies, is consistent with