We study photometric variable stars in two open clusters of very different age: σ Orionis (τ ˜ 3 Ma, d ˜ 385 pc) and NGC 6811 (τ ˜ 600 Ma, d ˜ 1000 pc). In NGC 6811 we expected to detect pulsations in known δ Scuti stars that are also observed in the Kepler field, from which we calculate the frequency spectra, and derive information about the

Recent observations show that inner disks and rings (IDs and IRs) are not preferentially found in barred galaxies, pointing to the relevance of formation mechanisms different to the traditional bar-origin scenario. Nevertheless, the role of minor mergers in the formation of these inner components (ICs), while often invoked, is still poorly

These tables contain all the parameters that have been computed, based on the LR8 spectra of targets selected as being foreground Galactic members. The atmospheric parameters were computed using the pipeline presented in Kordopatis et al. (2011A&A...535A.106K). The line-of-sight distances and the projected atmospheric parameters were computed by

The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located at the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys. The OAJ facility will have two wide-field telescopes: the T250/JST; a 2.55-m telescope with a 3° diameter FoV, and the T80/JAST; a 0.83 m telescope

Context. During the past 100 years, helium emission lines have never been observed in RR Lyrae stars, especially in RRab-type ones where strong shock waves are nevertheless present in their atmosphere. Only recently have the observation of He I emission lines in 10 RRab stars and the detection of very weak He II emission in 3 of them been reported

In a recent published study we have analysed the evolution of the bar pattern speed with redshift using morphological measurements of a sample of low-inclination ringed galaxies from the SDSS and the COSMOS survey. In this paper we summarise the results obtained in that work. The sample covers a redshift range 0