Surface distribution of small-scale magnetic field on the active cool star LQ Hydrae




Kochukhov O., Hackman T., Lehtinen J. J.

2023

 Astronomy and Astrophysics

ASTRONOMY & ASTROPHYSICS

L17

680

0004-6361

1432-0746

DOIhttps://doi.org/10.1051/0004-6361/202347930

https://www.aanda.org/articles/aa/full_html/2023/12/aa47930-23/aa47930-23.html

https://research.utu.fi/converis/portal/detail/Publication/380635020



It is well known that small-scale magnetism dominates the surface magnetic field topologies of active late-type stars. However, little information is available on the spatial distribution of this key magnetic field component. Here, we take advantage of the recently developed magnetic field diagnostic procedure relying on the magnetic intensification of iron atomic lines in the optical. We extend this methodology from measuring a single average field strength value to simultaneous Doppler imaging reconstruction of the two-dimensional maps of temperature and magnetic field strength. We applied this novel surface mapping approach to two spectroscopic data sets of the young active Sun-like star LQ Hya. For both epochs, we found a fairly uniform field strength distribution, apart from a latitudinal trend of the field strength increasing from 1.5–2.0 kG at low latitudes to 3.0–3.5 kG, close to the rotational poles. This distribution of the small-scale field does not display a clear correlation with the locations of temperature spots or the global magnetic field structure reconstructed for the same epochs.


Last updated on 26/11/2024 10:26:14 PM