Brightness variations due to dark spots on the stellar surface encode information about stellar surface rotation and magnetic activity. In this work, we analyze the Kepler long-cadence data of 26,521 main-sequence stars of spectral types M and K in order to measure their surface rotation and photometric activity level. Rotation-period estimates are

Context. Only a few open clusters are as important for the study of stellar and substellar objects, and their formation and evolution, as the young σ Orionis cluster. However, a complete spectroscopic characterisation of its whole stellar population is still missing. Aims: We filled most of that gap with a large spectroscopic and astrometric survey

The star formation main sequence (SFMS) is a tight relation between the galaxy star formation rate (SFR) and its total stellar mass (M⋆). Early-type galaxies (ETGs) are often considered as low-SFR outliers of this relation. We study, for the first time, the separated distribution in the SFR versus M⋆ of bulges and discs of 49 ETGs from the CALIFA

We report the discovery of the microlensing planet OGLE-2018-BLG-0740Lb. The planet is detected with a very strong signal of Δχ 2 ∼ 4630, but the interpretation of the signal suffers from two types of degeneracies. One type is caused by the previously known close/wide degeneracy, and the other is caused by an ambiguity between two solutions, in

We present Near-Infrared spectra of 11 objects in the Chaldaea asteroid family obtained with NASA's InfraRed Telescope Facility (IRTF) and the Telescopio Nazionale Galileo (TNG) between January 2017 and July 2019. From our sample we conclude that Chaldaea objects have red slopes and positive curvature, and are essentially identical to each other

The population of near-Earth objects (NEOs) shows a large variety of physical and dynamical properties. Their study is relevant for the science of planetary systems and for practical reasons regarding space exploration and long-term probability of impact with the Earth. We report the spectral and spectro-photometric data of 135 NEOs. These are