The distribution of stars in the Hertzsprung-Russell diagram narrates their evolutionary history and directly assesses their properties. Placing stars in this diagram however requires the knowledge of their distances and interstellar extinctions, which are often poorly known for Galactic stars. The spectroscopic Hertzsprung-Russell diagram (sHRD)

We estimate the typical spectrum of spatial fluctuations of intensity due to the penumbral filaments. High angular resolution continuum images are used (cut-off frequencies equivalent to 0.28" wavelength of about 5257 Å). The amplitude of the observed spectra follows the modulation transfer function of our optical system. In other words, the

We present V, I CCD photometry of the Sextans dwarf spheroidal galaxy (dSph) in the Local Group. Images of the galaxy were taken by Suprime-Cam on Subaru, covering 26 fields extended to the tidal radius. The color-magnitude diagrams extending two magnitudes below the main-sequence turnoff (MSTO) show a steep red giant branch (RGB), blue and red

We present a study of the star formation process in the giant H II region NGC 5471 in the outskirts of M 101 from both integrated and resolved photometry. Stellar population analysis with the code CHORIZOS is compatible with the hypothesis that this regions has, at least, two different populations. The color-magnitude diagram of the region as

STELLA is a robotic observatory with two fully automatic telescopes (STELLA-I and STELLA-II) located at the Teide Observatory in Tenerife, Spain. Not only the telescopes are automatic but also the entire observatory, no human presence is needed for observing - not even in remote control. STELLA-I supports a high-resolution, fiber-fed and bench

We have taken advantage of a stellar occultation by the dwarf planet Makemake on 2011 April 23, to determine several of its main physical properties. We present results from a multisite campaign with 8 positive occultation detections from 5 different sites, including data from the 8-m VLT and 3.5-m NTT telescopes in Chile, which have very high