We present results of narrowband (Hα and adjacent continuum) and broadband (U, B, and V) optical CCD imaging together with high-resolution Hα spectroscopy of the blue compact Wolf-Rayet dwarf galaxies POX 4 and Tol 35. POX 4 has a fainter, irregular, and diffuse companion located 20.5" (4.7 kpc) along the minor axis of the galaxy, which is visible

Not Available

The thermal spectrum of the zodiacal light cannot be observed from the ground. We collected 27 mid-infrared (6-12mu m) spectra obtained by the spectrophotometer ISOPHOT-S on-board the Infrared Space Observatory (ISO). The observed positions are distributed over the sky region accessible by ISO. The spectrum of the zodiacal light is remarkably well

The distance, star formation history and global properties of the Local Group dIrr galaxy SagDIG are derived based on an [I-(V-I)] colour-magnitude diagram of ~ 1550 stars. A distance of 1.06+/- 0.10 Mpc is obtained from the I magnitude of the TRGB. This corresponds to 1.17 Mpc to the barycenter of the Local Group and 1.34 to M 31, being DDO 210

The planetary nebula NGC 2392 possesses an extremely unusual spectrokinematic morphology, characterized by several strange and elusive structures. In this paper, extensive narrowband imaging of the source is used to investigate the shell excitation structure, while [O III] and [S II] images are ratioed to provide fully sampled mapping of electron

Convective line asymmetries in the optical spectrum of two metal-poor stars, Gmb 1830 and HD 140283, are compared to those observed for solar metallicity stars. The line bisectors of the most metal-poor star, the subgiant HD 140283, show a significantly larger velocity span that the expectations for a solar-metallicity star of the same spectral