Context. Short- to mid-term magnetic phenomena on the stellar surface of M-type stars can resemble the effects of planets in radial velocity data, and may also hide them. Aims: We analyze 145 spectroscopic HARPS-N observations of GJ 3942 taken over the past five years and additional photometry in order to disentangle stellar activity effects from

We report the discovery of a radio-quiet type 2 quasar (SDSS J165315.06+234943.0 nicknamed the `Beetle' at z = 0.103) with unambiguous evidence for active galactic nucleus (AGN) radio-induced feedback acting across a total extension of ˜46 kpc and up to ˜26 kpc from the AGN. To the best of our knowledge, this is the first radio-quiet system where

Digital tools are increasingly used in cultural astronomy, so that it is now more important than ever to assess their precision and reliability, and to identify what uncertainties they may introduce. The present work aims to address these issues by comparing a dataset of orientations of Roman cities in the Iberian Peninsula measured in situ with

We report on long-term multiwavelength monitoring of blazar Mrk 421 by the GLAST-AGILE Support Program of the Whole Earth Blazar Telescope (GASP-WEBT) collaboration and Steward Observatory, and by the Swift and Fermi satellites. We study the source behaviour in the period 2007-2015, characterized by several extreme flares. The ratio between the

After the early observations of the disrupted asteroid P/2016 G1 with the 10.4 m Gran Telescopio Canarias (GTC) and modeling of the dust ejecta, we have performed a follow-up observational campaign of this object using the Hubble Space Telescope (HST) during two epochs (2016 June 28 and July 11). The analysis of these HST images with the same model

Context. Transit spectroscopy is one of the most commonly used methods to characterize exoplanets' atmospheres. From the ground, these observations are very challenging due to the terrestrial atmosphere and its intrinsic variations, but high-spectral-resolution observations overcome this difficulty by resolving the spectral lines and taking