From published catalogs, basic physical properties including diameters, masses, and neutral hydrogen contents of spiral galaxies have been studied as a function of the arm class. The results indicate that galaxies with well-defined arms have longer scale-lengths (a difference comparable in the red to that in the blue) and are more massive (in both

An experiment aimed at diffraction-limited imaging of astronomical sources in the 2-5-micron range is presented. It is based on a rotation shearing interferometer that produces fringes in the pupil plane that can be scanned through the zero optical path difference. The two-dimensional interferograms are recorded with an infrared camera looking at

We have studied the amount of diffuse light in two galaxy groups, Leo and HCG 44 through the detection of intragroup planetary nebulae (IGPNe). The emission line objects detected turned out to be compatible with background Lyα galaxies. We have estimated an upper limit to the amount of diffuse light in both groups assuming the presence of just one

We report the discovery of the first known symbiotic star in IC10, a starburst galaxy belonging to the Local Group, at a distance of ~750 kpc. The symbiotic star was identified during a survey of emission-line objects. It shines at V = 24.62 +/- 0.04,V - RC = 2.77 +/- 0.05 and RC - IC = 2.39 +/- 0.02, and suffers from EB- V = 0.85 +/- 0.05

The dynamics of the core of the Sagittarius (Sgr) dwarf spheroidal (dSph) galaxy are explored using high-resolution (R ~ 22, 500), H-band, near-infrared spectra of over 1000 giant stars in the central 3 deg2 of the system, of which 328 are identified as Sgr members. These data, among some of the earliest observations from the Sloan Digital Sky

We report the discovery of a galactic wind in the central region of the galaxy M100. This result is based on a careful 2D spectroscopic study performed on observations made with the fibre system INTEGRAL on the William Herschel Telescope. The primary evidence of the wind is the presence of blueshifted interstellar NaD absorption lines. The velocity