The Pristine survey uses narrow-band photometry on the region of the Ca II H & K absorption lines to find extremely metal-poor stars. With a spectroscopic follow-up sample of 205 stars in the magnitude range 14 V 18, we compute the success rates for finding extremely metal-poor stars and modify the selection criteria used to select stars for

Directly imaged substellar companions around stars are key objects for better understanding the formation and evolution of brown dwarfs and massive planets, as we can infer physical properties like the age, distance or metallicity from their host stars. Moreover, we can characterize them spectroscopically, seeking for features that may provide

We have serendipitously discovered that Leoncino Dwarf, an ultrafaint, low-metallicity record-holder dwarf galaxy, may have hosted a transient source, and possibly exhibited a change in morphology, a shift in the centre of brightness, and peak variability of the main (host) source in images taken approximately 40 yr apart; it is highly likely that

We have undertaken a comprehensive search for both Lyman alpha emitters (LAEs) and Lyman break galaxies (LBGs) in the Survey for High-z Absorption Red and Dead Sources (SHARDS) Survey of the Great Observatories Origins Deep Survey North field. SHARDS is a deep imaging survey, made with the 10.4 m Gran Telescopio Canarias, employing 25 medium band

One of the key research problems in stellar physics is to decipher the small-scale magnetic activity of the quiet solar atmosphere. Recent magneto-convection simulations that account for small-scale dynamo action have provided three-dimensional (3D) models of the solar photosphere characterized by a high degree of small-scale magnetic activity

We report the first detection of the Galactic Center massive black hole, Sgr A*, at 100 μm and 160 μm. Our measurements were obtained with PACS on board the Herschel satellite. While the warm dust in the Galactic Center is too bright to allow for a direct detection of Sgr A*, we measure a significant and simultaneous variation of its flux of {{Δ }}