The fragile and rare isotope 6Li has a spallative origin. It is rapidly destroyed in solar-type stars while fully preserved in low-mass brown dwarfs and planets. So far, 6Li has been unambigiously detected in only few metal-poor halo and disk stars whereas it has never been observed with a high level of confidence in any metal-rich or even solar

We present a general analytical formalism to calculate accurately several statistics related to underdense regions in the Universe. The statistics are computed for dark matter halo and galaxy distributions both in real space and redshift space at any redshift. Using this formalism, we found that void statistics for galaxy distributions can be

We present an overview and a brief report on the status of the STELLA project (abbreviation for STELLar Activity). The STELLA-I telescope will be the first robotic telescope that feeds a bench-mounted high-resolution Echelle spectrograph with a set of 50 and 100 μm fibres and provides spectral resolutions of up to 47,000 with a 1 arcsec slit. The

In the luminosity functions (LF's) of the HII regions of a set of late-type spiral galaxies we have identified the presence of a phase-change via a jump in the function accompanied by a change in slope.The nature of the phase-change is diagnosed using measurements of the internal radial surface brightness of individual regions.Plotting the internal

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

Nowadays it is well established that BCDs are mostly old systems, as the vast majority of them have an extended low-surface brightness (LSB) stellar host underlying their central starburst component. This host generally extends several kpc from the star-forming (SF) regions, shows regular elliptical isophotes, and displays red colors indicative of