eROSITA has unleashed a deluge of observations of the stellar X-ray sky in a nexus with other powerful complementary capabilities, such as TESS and Gaia. At the same time, a feeding frenzy of the exoplanet field hungry for data on planetary energetic radiation environments has driven a renaissance of interest and research into stellar coronae and what used to be the backwater of high energy...
The eROSITA all-sky survey (eRASS) largely increased the number of well-characterized X-ray detected stars.
I will present our method, called HamStar, to identify these stars among all eROSITA sources. HamStar assigns
each eROSITA source a value, p_stellar, that describes the individual probability of the source to be stellar
in nature. HamStar uses a Bayesian-framework taking advantage...
The solar corona is often invoked as a template for stellar ones, but the significant difference between solar and non-solar instruments and data makes direct comparison between X-ray observations of the Sun, which is usually of the resolved solar disk, and stellar point-source observations almost impossible. In order to overcome this hurdle, the research group at INAF Osservatorio Astronomico...
Volume-complete samples are key to characterizing stellar populations. We have set out to constrain the activity and rotation rates of all 150 early-M dwarf stars from the `10pc sample in the era of Gaia' (from Reyle et al. 2021). Hereby, we uncover the full spread that such stars can exhibit, which we find to span three orders of magnitude both in X-ray brightness and rotation period.
At...
