Astrophysical: Chromospheres

  • Publication
    Polarisation and magnetic fields in cool stars and the Sun. A session in memory of Meir Semel
    Astrophysical plasmas and magnetic fields are inextricably coupled to each other. But magnetic fields are elusive; they cannot be fully characterized with...
  • Publication
    Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators
    We determine rotation periods of a sample of 48 late F-type to mid-M dwarf stars using time series high-resolution spectroscopy of the Ca II H&K and H α...
  • Publication
    Simultaneous photometric and CARMENES spectroscopic monitoring of fast-rotating M dwarf GJ 3270. Discovery of a post-flare corotating feature
    Context. Active M dwarfs frequently exhibit large flares, which can pose an existential threat to the habitability of any planet in orbit in addition to making...
  • Publication
    Spectroscopic Identification of DENIS-selected Brown Dwarf Candidates in the Upper Scorpius OB Association
    We present low-resolution (R=900) optical (576.1-1051.1 nm) spectroscopic observations of 40 candidate very low mass members in the Upper Scorpius OB...
  • Publication
    Temporal changes of the flare activity of Proxima Centauri
    Context. We study temporal variations of the emission lines of Hα, Hɛ, H and K CaII, D1 and D2 NaI, He4026, and He5876 in the HARPS spectra of Proxima Centauri...
  • Publication
    The CARMENES search for exoplanets around M dwarfs. Behaviour of the Paschen lines during flares and quiescence
    The hydrogen Paschen lines are known activity indicators, but studies of them in M dwarfs during quiescence are as rare as their reports in flare studies. This...
  • Publication
    The CARMENES search for exoplanets around M dwarfs. Chromospheric modeling of M 2-3 V stars with PHOENIX
    Chromospheric modeling of observed differences in stellar activity lines is imperative to fully understand the upper atmospheres of late-type stars. We present...
  • Publication
    The CARMENES search for exoplanets around M dwarfs. Diagnostic capabilities of strong K I lines for photosphere and chromosphere
    There are several strong K I lines found in the spectra of M dwarfs, among them the doublet near 7700 Å and another doublet near 12 500 Å. We study these...
  • Publication
    The CARMENES search for exoplanets around M dwarfs. Period search in Hα, Na I D, and Ca II IRT lines
    We use spectra from CARMENES, the Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs, to search...