Publicaciones

  • Digging into the mystery of the Galactic globular clusters M22 and NGC1851

    We propose to collect deep near-infrared (NIR) images of two peculiar Galactic globular clusters (GGCs), NGC1851 and M22, to explore the properties of their multiple stellar populations. These GGCs display multiple sequences along the red-giant and sub-giant branches in ultraviolet-optical color-magnitude diagrams (CMDs), and spectroscopy confirmed

    Calamida, Annalisa et al.

    Fecha de publicación:

    5
    2020
  • Asteroseismic masses of four evolved planet-hosting stars using SONG and TESS: resolving the retired A-star mass controversy

    The study of planet occurrence as a function of stellar mass is important for a better understanding of planet formation. Estimating stellar mass, especially in the red giant regime, is difficult. In particular, stellar masses of a sample of evolved planet-hosting stars based on spectroscopy and grid-based modelling have been put to question over

    Malla, Sai Prathyusha et al.

    Fecha de publicación:

    6
    2020
  • Optical spectroscopy of BL Lac objects: TeV candidates

    We investigate the spectroscopic optical properties of gamma-ray sources detected with high significance above 50 GeV in the Third Catalog of Hard Fermi-LAT Sources and that are good candidates as TeV emitters. We focus on the 91 sources that are labelled by the Fermi team as BL Lac (BLL) objects or blazar candidates of uncertain type (BCUs), are

    Paiano, Simona et al.

    Fecha de publicación:

    6
    2020
  • Spectral library of age-benchmark low-mass stars and brown dwarfs

    In recent years, some extremely red brown dwarfs have been discovered. They were believed to have a low surface gravity, but many of their spectral characteristics are similar to those of high-surface-gravity brown dwarfs, showing that the spectral characteristics of young brown dwarfs are poorly understood. We aim to test surface-gravity

    Manjavacas, E. et al.

    Fecha de publicación:

    6
    2020
  • A New Class of Roche Lobe-filling Hot Subdwarf Binaries

    We present the discovery of the second binary with a Roche lobe-filling hot subdwarf transferring mass to a white dwarf (WD) companion. This 56 minute binary was discovered using data from the Zwicky Transient Facility. Spectroscopic observations reveal an He-sdOB star with an effective temperature of Teff = 33,700 ± 1000 K and a surface gravity of

    Kupfer, Thomas et al.

    Fecha de publicación:

    7
    2020
  • Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C

    On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on

    Acciari, V. A. et al.

    Fecha de publicación:

    7
    2020