With the recovery of comet 103P/Hartley 2, the target of the EPOXI mission, we have begun the characterization of the nucleus necessary for the mission. Observations from past apparitions of this comet show that it typically begins activity while far from the sun, near r = 4 AU (about 450 days pre-perihelion). This makes obtaining information about

Detailed surface photometry has been carried out for three barred galaxies with use of high resolution CCD broad-band images in the B, V and I bands. Using azimuthal luminosity profiles and their decomposition into Fourier Series, the structural parameters (length and strength) of the bars in the three galaxies have been obtained. We have also

Metallicity gradients provide strong constraints for understanding the chemical evolution of the Galaxy. We report on radial abundance gradients of Fe, Ni, Ca, Si, and Mg obtained from a sample of 304 red-giant members of 29 disk open clusters, mostly concentrated at galactocentric distances between ˜ 8-15 kpc, but including two open clusters in

Using high-resolution (R~30000), high-quality (S/N>=60 per pixel), we obtained spectra for twelve stars in four open clusters with the fibre spectrograph FOCES, at the 2.2 Calar Alto Telescope in Spain.We employ a classical equivalent-width analysis to obtain accurate abundances of sixteen elements: Al, Ba, Ca, Co, Cr, Fe, La,Mg, Na, Nd, Ni, Sc, Si

We have obtained new narrowband CCD images, spatially resolved intermediate- and high-dispersion spectroscopic observations of the Ring Nebula (NGC 6720). These data reveal that the bright main nebula is not a real ring, but a closed shell. A prolate ellipsoidal geometry for this shell is inferred from the observed tilts in the [N II] velocity

Spatial resolved low resolution spectroscopy of the haloes around the planetary nebulae NGC 6543 and NGC 6826 were conducted. The results imply that the radiation is thermal and not due to dust reflection. From those data chemical abundances and masses were calculated. Chemical abundances decrease in the haloes, while masses increase up to ten