In this work, we study the gravitational influence of the material extending from Uranus orbit to the Kuiper belt and beyond on objects moving within these regions. We conclude that a density distribution given by ρ (r)=(1)/(r) (for r >= 20 AU) generates a constant acceleration towards the Sun on those objects, which, with the proper amount of mass

We present the results of a spectroscopic analysis of bright stars in the Carina dSph galaxy. We collected low-resolution FORS2@VLT spectra of ≈ 200 stars. Our spectroscopic targets have been selected among the evolved Carina stars, in particular we selected low-mass, old Red Giant, Asymptotic, and Horizontal Branch stars, as well as intermediate

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Oxygen abundances of a large number of metal-rich stars, with and without known planets, were derived from the forbidden line [O I] 6300 Å, the OI 7771-5 Å triplet and from near-UV OH lines. Non-LTE corrections were calculated and applied to the LTE abundance results derived from the OI 7771-5 Å triplet. Spectral synthesis was performed for several

OO Serpentis is a deeply embedded young star which brightened by 5 mag in Kband between 1994 and 1995, and gradually faded afterwards. In many respects the star and its outburst is very similar to the well-known young eruptive stars (FUors and EXors). We monitored the eruption of OO Ser for 20 months with the Infrared Space Observatory in the 3.6

Using high resolution optical spectroscopy (R˜40,000-50,000) we have derived the Li and Zr abundances of a large sample of galactic O-rich AGB stars. Our chemical analysis shows that some stars are Li overabundant while others are not. The observed Li overabundances are attributed to the activation of the so-called ``hot bottom burning'' (HBB)