Context. For over 12 yr, we have carried out a precise radial velocity (RV) survey of a sample of 373 G- and K-giant stars using the Hamilton Échelle Spectrograph at the Lick Observatory. There are, among others, a number of multiple planetary systems in our sample as well as several planetary candidates in stellar binaries. Aims: We aim at

The work reported here demonstrates that it is possible to accurately determine surface gravities of δ Scuti (δ Sct) stars using the frequency content from high-precision photometry and a measurement of the parallax. Using a sample of 10 eclipsing binary systems with a δ Sct component and the unique δ Sct star discovered with a transiting planet

Two sample-return missions, OSIRIS-REx and Hayabusa 2, have just arrived at primitive near-Earth asteroids (NEAs) (101955) Bennu and (162173) Ryugu, and it is of interest to predict the effects of space weathering on their surfaces. Most spacecraft-accessible NEAs originate in the inner asteroid belt, and these two sample-return targets most likely

The 10m Gran Telescopio Canarias (GTC) is currently being installed in the Observatorio del Roque de los Muchachos (ORM) on the island of La Palma. An adaptive optics (AO) system will be installed at one of the Nasmyth foci of the telescope within a year of the telescope being commissioned. The preliminary design of the adaptive optics system is

This investigation aims to study the correlation of the solar background with atmosphere. We used high resolution observations of the NaDl spectral line. In fact the large span in formation heights of this spectral line allowed us to infer the signal from photosphere to chromosphere. We analyzed the data by applying the SIR code (Stokes Inversion

Primitive asteroids contain the most pristine material that gave birth to the rocky planets. Interest in spectral data from primitive asteroids that could be the source of the primitive near-Earth asteroids (NEAs) has increased in anticipation of the two sample-return missions that will reach their targets in the next four years and bring samples