Aims: We study the presence of reversed polarity magnetic flux in sunspot penumbra. Methods: We applied a new regularized method to deconvolve spectropolarimetric data observed with the spectropolarimeter SP onboard Hinode. The new regularization is based on a principal component decomposition of the Stokes profiles. The resulting Stokes profiles

We showed in previous works that a periodic pattern could be found in the frequency set of δ Sct stars observed by CoRoT. We related that pattern with a value of the large separation. However, are these stars particular cases? We present here preliminary results of our work aimed at answering this and related questions. We looked for periodicities

The Apache Point Observatory Galactic Evolution Experiment (APOGEE) is an SDSS-III survey that is obtaining high resolution near-IR (H band) spectra of 100,000 Milky Way stars in an effort to chemically trace formation and evolution of Galactic stellar populations. Optical echelle spectra of a small subset of survey targets have been obtained with

Context. Magnetars are an extreme, highly magnetized class of isolated neutron stars whose large X-ray luminosity is believed to be driven by their high magnetic field. Aims: We study for the first time the possible very high energy γ-ray emission above 100 GeV from magnetars, observing the sources 4U 0142+61 and 1E 2259+586. Methods: We observed

We study two δ Scuti stars, V830 Her and HD 163032, using four-year asteroseismic photometric data taken with the Taiwan Automated Telescope Network. We check the consistency of the pulsational frequencies obtained from data of different years and sites with three different methods to remove the artificial frequencies. Fourteen frequencies are

We present initial abundance gradients in the Milky Way as determined from high-resolution (R > 20,000) spectra of red giant stars. Our observations were taken with the SDSS-III APO Galactic Evolution Experiment (APOGEE) and have a S/N of at least 100. APOGEE is able to sample a large range of Galactocentric radii (RGC) including the bulge and