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

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

We have identified a correlation of increasing albedo for increasing phase-function slope using ground-based and spacecraft observations of 14 Jupiter-family comets (JFCs). This can be interpreted as an evolutionary path of JFCs, according to which dynamically young JFCs start their evolution with relatively high albedos and steeper phase functions

Overview of the science cases for, and technologies required for a new single dish sub-mm telescope. AtLAST is envisioned as a 50m diameter single dish with a 1deg field of view that will be able to map the large scale structures of the Universe inaccessible to ALMA with mapping speeds 1000s of times faster than current or planned facilities.

From CCD observations carried out with different telescopes, we present short-term photometric measurements of the large trans-Neptunian object Varuna in 10 epochs, spanning around 19 years. We observe that the amplitude of the rotational light curve has changed considerably during this period of time from 0.41 to 0.55 mag. In order to explain this

The present work aims to characterize some of the possible sources of near-Earth asteroids Bennu and Ryugu, targets of the sample-recovery missions OSIRIS-REx and Hayabusa2, respectively. The characterization of the sources of these NEAs will enhance the scientific results of the missions, helping to understand how these objects reach their current