We present a study of the dust-to-gas ratios in five nearby galaxies: NGC 628 (M74), NGC 6503, NGC 7793, UGC 5139 (Holmberg I), and UGC 4305 (Holmberg II). Using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury program Legacy ExtraGalactic UV Survey (LEGUS) combined with archival HST/Advanced Camera for Surveys

We present the detection and follow-up observations of planetary candidates around low-mass stars observed by the K2 mission. Based on light-curve analysis, adaptive-optics imaging, and optical spectroscopy at low and high resolution (including radial velocity measurements), we validate 16 planets around 12 low-mass stars observed during K2

Aim. The lack of large-angle correlations in the fluctuations of the cosmic microwave background (CMB) conflicts with predictions of slow-roll inflation. But while probabilities (≲0.24%) for the missing correlations disfavour the conventional picture at ≳3σ, factors not associated with the model itself may be contributing to the tension. Here we

Aims: Our goal is to probe the inner structure and the nature of the mid-IR emission in the active galaxy IC 3639, which hosts a Seyfert 2 nucleus and shows signatures of strong star-forming activity. Methods: We used interferometric observations in the N-band with VLTI/MIDI to resolve the mid-IR emission of this nucleus. The origin of the nuclear

Presentamos un estudio arqueoastronómico del yacimiento arqueológico de La Malladeta (La Vila Joiosa, Alicante), santuario ibérico y posteriormente romano altoimperial que se utilizó entre los siglos iv a. C. y i d. C. situado en la cima de un promontorio costero. El seguimiento fotográfico de los ortos solares desde la cima del santuario en fechas

El principal propòsito de esta tesis ha sido la búsqueda y caracterización de estrellas pobres en metales. Para ello se han analizado más de tres millones de espectros de baja resolución provenientes de Sloan Sky Digital Survey (SDSS) y de Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), y elaborado un catálogo de estrellas