2 research outputs found
First Chromospheric Activity and Doppler Imaging Study of PW And Using a New Doppler Imaging Code: SpotDIPy
Measuring coverage of dark spots on cool stars is important in understanding
how stellar magnetic activity scales with the rotation rate and convection zone
depth. In this respect, it is crucial to infer surface magnetic patterns on G
and K stars, to reveal solar-like stellar dynamos in action. Molecular bands
serve as invaluable indicators of cool spots on the surfaces of stars, as they
play a crucial role in enabling accurate assessments of the extent of spot
coverage across the stellar surface. Therefore, more reliable surface images
can be obtained considering the inversion of atomic lines with molecular bands.
In this context, we simultaneously carry out Doppler imaging (DI) using atomic
lines as well as Titanium Oxide (TiO) band profiles of PW And (K2 V) and also
investigate chromospheric activity indicators for the first time in the
literature, using the high-resolution spectra. The surface spot distribution
obtained from the inversion process represents both atomic line and TiO-band
profiles quite accurately. The chromospheric emission is also correlated with
photospheric spot coverage, except during a possible flare event during the
observations. We detect frequent flare activity, using TESS photometry. We also
introduce a new open-source, Python-based DI code SpotDIPy that allows
performing surface reconstructions of single stars using the maximum entropy
method. We test the code by comparing surface reconstruction simulations with
the extensively used DoTS code. We show that the surface brightness
distribution maps reconstructed via both codes using the same simulated data
are consistent with each other.Comment: Accepted for publication by the Astrophysical Journa