During its four years of photometric observations, the Kepler space telescope detected thousands of exoplanets and exoplanet candidates. One of Kepler's greatest heritages has been the confirmation and characterization of hundreds of multi-planet systems via transit timing variations (TTVs). However, there are many interesting candidate systems

Context. Cosmic rays and magnetic fields play an important role for the formation and dynamics of gaseous halos of galaxies. Aims: Low-frequency radio continuum observations of edge-on galaxies are ideal to study cosmic-ray electrons (CREs) in halos via radio synchrotron emission and to measure magnetic field strengths. Spectral information can be

Themis is a 90 cm solar telescope which undergoes a rejuvenation of its scientific instruments. In particular, it is about to be equipped with an adaptive optics (AO) system with a bandwidth of at least 1 kHz and featuring a 97 actuator deformable mirror and 10×10 Shack-Hartmann wavefront sensor. Nowadays, the computational power required by such a

This contribution is focused on the innovative aspects of the design of the Laser Guide Star (LGS) Facility for the Gran Telescopio Canarias (GTC) Adaptive Optics (GTCAO) System [6]. After a trade-off process considering different alternatives, a preliminary opto-mechanical design was defined, based on a "TOPTICA SodiumStar" laser to be launched on

Context. Cosmic chronometers may be used to measure the age difference between passively evolving galaxy populations to calculate the Hubble parameter H(z) as a function of redshift z. The age estimator emerges from the relationship between the amplitude of the rest frame Balmer break at 4000 Å and the age of a galaxy, assuming that there is one

We report on 16 BL Lacertae objects that were proposed to be at z > 1. We present spectroscopic observations secured at the 10.4 m GTC that allowed us to assess the redshift of these sources. In particular, for five objects, we disprove the previous value of the redshift reported in the literature and found that they lie at z 1. Moreover, two of