We study the behaviour of the interstellar R_n_=n(Zn^+^)/n(Na^0^) ratio in ionization equilibrium conditions. The ratio is very sensitive to variations of the...

We present time-series photometry of 31 massive DA white dwarfs with M ≳ 0.9 M ⊙ within the ZZ Ceti instability strip from the Montreal White Dwarf Database 100...

A great deal of effort has been made in recent years to probe the gas fraction evolution of massive quiescent galaxies (QGs); however, a clear picture has not...

We have measured the ^12^C/^13^C interstellar ratio in the Coalsack, a prominent dark nebula in the southern sky, by means of high resolution (λ/δλ=6x10^4^)...

Context: We present an extensive ground-based photometric and spectroscopic campaign of the γ Dor CoRoT target HD 49434. This campaign was a preparatory step of...

Context. HD 49434 is a bright (V = 5.75 m) and multiperiodic γ Dor-type pulsator that has been selected for the asteroseismic core programme of the CoRoT...

Aims: The Antarctica Search for Transiting Extrasolar Planets (ASTEP), an automatized 400 mm telescope located at Concordia station in Antarctica, monitored β...

The almogaren (rock-cut sanctuary) of Risco Caído was discovered in 1996 in the Canary island of Gran Canaria. It is a paradigmatic example of a complex where...

Context: Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect...