Context. Understanding solar surface magnetoconvection requires the study of the Fourier spectra of the velocity fields. Nowadays, observations are available that resolve very small spatial scales, well into the subgranular range, almost reaching the scales routinely resolved in numerical magnetoconvection simulations. Comparison of numerical and

We obtained high-resolution spectra for 94 candidate stars belonging to the HB of M 22 with FLAMES. Previous works have indicated that this cluster has split subgiant (SGB) and red giant branches (RGB) and hosts two different stellar populations, differing in overall metal abundance and both exhibiting a Na-O anti-correlation. The HB stars we

Polarization measurements of the microquasar Cygnus X-1 exist at γ-ray, X-ray, ultraviolet, optical and radio frequencies. The γ-ray emission has been shown to be highly linearly polarized. Here, we present new infrared polarimetric data of Cygnus X-1 taken with the 10.4 m Gran Telescopio Canarias and the 4.2 m William Herschel Telescope. We show

We study the dark and luminous mass distributions, circular velocity curves (CVCs), line-of-sight kinematics and angular momenta for a sample of 42 cosmological zoom simulations of galaxies with stellar masses from 2.0 × 1010 to 3.4 × 1011 M⊙ h-1. Using a temporal smoothing technique, we are able to reach large radii. We find the following. The

Aims: In this work, we use long-slit spectroscopy observations of a transit event of the close-in orbiting planet WASP-43b (Mp = 2.034 MJup, Rp = 1.036 RJup) in an effort to detect its atmosphere. Methods: We used the Gran Telescopio Canarias (GTC) instrument OSIRIS to obtain long-slit spectra in the optical range 520-1040 nm of the planetary host

We report the discovery of a peculiar L dwarf from the United Kingdom Infrared Deep Sky Survey Large Area Survey, ULAS J222711-004547. The very red infrared photometry (MKO J - K = 2.79 ± 0.06, WISE W1-W2 = 0.65 ± 0.05) of ULAS J222711-004547 makes it one of the reddest brown dwarfs discovered so far. We obtained a moderate resolution spectrum of