High-sensitivity measurements of the linearly polarized solar limb spectrum produced by scattering processes in quiet regions of the solar atmosphere showed that the Q/I profile of the lithium doublet at 6708 Å has an amplitude ~10-4 and a curious three-peak structure, qualitatively similar to that found and confirmed by many observers in the Na I

We present long-slit optical spectra along the major axis of the planetary nebula NGC 7009. These data allow us to discuss the physical, excitation, and chemical properties of all the morphological components of the nebula, including its remarkable systems of knots and jets. The main results of this analysis are the following: (1) the electron

We present a detailed analysis of IC 4776, a planetary nebula displaying a morphology believed to be typical of central star binarity. The nebula is shown to comprise a compact hourglass-shaped central region and a pair of precessing jet-like structures. Time-resolved spectroscopy of its central star reveals a periodic radial velocity variability

PLATO 2.0 has recently been selected for ESA's M3 launch opportunity (2022/24). Providing accurate key planet parameters (radius, mass, density and age) in statistical numbers, it addresses fundamental questions such as: How do planetary systems form and evolve? Are there other systems with planets like ours, including potentially habitable planets

Extensive surveys of the Milky Way have provided a global view of the population of planetary nebulae in the Milky Way. Their chemical, dynamical, and morphological properties, the link with their red giant progenitors and white dwarf descendants, and the implications on our understanding of the chemical evolution of the Galaxy, are discussed.

The observed parameters of the young super star cluster M82-A1 and its associated compact H II region are here shown to indicate a low heating efficiency or immediate loss, through radiative cooling, of a large fraction of the energy injected by stellar winds and supernovae during the early evolution of the cluster. This implies a bimodal