Flaring stars and brown dwarfs radio emission

DOI

The vicinities of intermediate-to-late type dwarf stars are considered as an adequate terrain to host planets suitable for life to form. However, they are oftentimes showing increased stellar activity, which should be taken into consideration when seeking potential habitable planetary systems. With the aim to reveal the effects of the magnetic field to the multi-band activity of dwarf stars, we search for associated radio emission for an extensive list of 14915 brown dwarfs and 15124 flaring stars. Methods. We utilised the first and second epoch catalogues and radio maps from all three epochs of the VLASS, supplemented with X-ray catalogues based on observations by the ROSAT, eROSITA, and XMM-Newton space telescopes, and 2-minute cadence optical light curves from the TESS mission. The radio-detected sub-sample was queried for concurrent TESS observations, and sources with coinciding light-curves were studied individually. We found no associated radio emission for brown dwarfs, and found 55 radio counterparts for the sample of flaring stars, out of which 7 have coincident TESS observations. The radio-detected sample follows both the radio-X-ray and the period-activity relations. We found a strong correlation between the radio powers and the stellar parameters of surface gravity, radius, and mass. We found no connection between the flare rate and the radio variability. For radio-detected stars with available effective temperatures and rotational periods, we estimated gyrochronological ages, which resulted in values of Tgyro<~1Gyr, with the majority of the sample being younger than 150Myr. We found no strong connection between the occurrence of optical flares and radio variability for the individually studied stars. We conclude that radio emission from intermediate-to-late type flaring stars is of synchrotron nature, and shares a common origin with X-ray processes. It is created by a predominantly young stellar population, and is the collective contribution of stellar flares, accretion, and coronal heating.

Cone search capability for table J/A+A/699/A337/tablea1 (List of the 55 radio detected flaring stars)

Identifier
DOI http://doi.org/10.26093/cds/vizier.36990337
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/699/A337
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/699/A337
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/699/A337
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/699/A337
Provenance
Creator Perger K.; Seli B.; Vida K.
Publisher CDS
Publication Year 2025
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Natural Sciences; Physics; Stellar Astronomy