RVs of TIC 56913729 & TIC 97729372 from LAMOST DR10

Utilizing data from the Transiting Exoplanet Survey Satellite (TESS) and LAMOST, we present a photometric and spectroscopic investigation of two new K-type low-mass eclipsing binaries, TIC 56913729 and TIC 97729372. Our analysis yields masses and radii for TIC 56913729, M_1_=0.7822+/-0.0054M_{sun}, R_1=0.7891+/-0.0021R_{sun}, and M_2=0.7532+/-0.0052M_{sun}, R_2=0.7648+/-0.0021R_{sun}. For TIC 97729372, the results are M_1=0.6410+/-0.0058M_{sun}, R_1=0.6537+/-0.0069R_{sun} and M_2=0.6480+/-0.0058M_{sun}, R_2=0.6418+/-0.0062R_{sun}_. In addition, by analyzing the out-of-eclipse starspot light variations, the lower limit of starspot coverage varies in different TESS sectors from 2% to 12%. We observed a clear radius inflation in the mass-radius diagram for both stars, when plotted against PARSEC and SPOT isochrones with 1Gyr. Yet, this apparent discrepancy disappears when the comparison is made with either an older PARSEC isochrone (12Gyr) or a SPOT isochrone (250Myr) with high starspot coverage (Fspot ~85%), which is significantly higher than the typical starspot coverage deduced from light curves. Due to the lack of strong age constraints, we cannot firmly exclude that the observed radius inflation may be the result of a post-main-sequence evolutionary effect, although the spectral and kinematic properties of these stars are hardly compatible with 10-12Myr old (Pop II) stars. It is more likely that the radius inflation is produced by the strong magnetic activity in these rapidly rotating stars, even if it is impossible to infer the actual total spot coverage, due to the age uncertainties.

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/AJ/168/253
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/168/253
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/168/253
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/AJ/168/253
Provenance
Creator Pan Y.; Frasca A.; Wang J.-X.; Fu J.-N.; Zhang X.-B.
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; Exoplanet Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy