Asteroseismology and interferometry of the F7V spectroscopic binary χ Draconis A in the TESS CVZ

@misc{rudrasingam2026asteroseismology,
  title = {{Asteroseismology and interferometry of the F7V spectroscopic binary $χ$ Draconis A in the TESS CVZ}},
  author = {Jonatan Rudrasingam and Mikkel N. Lund and Frank Grundahl and Arnab Chowhan and Timothy R. Bedding and Poul E. Nissen and Aldo Serenelli and Joel M. J. Ong and Jeppe S. Thomsen and Yaguang Li and Eva Panetier and Sarbani Basu and Owen J. Scutt and Travis S. Metcalfe and Savita Mathur and Mark Lykke Winther and George T. Hookway and Benjamin J. S. Pope and Amalie Stokholm and Desmond H. Grossmann and Jens R. Larsen and Jørgen Christensen-Dalsgaard and Daniel Huber and Mads S. Fredslund and Timothy R. White and Paul G. Beck and Pere L. Pallé and Rafael A. García and Hans Kjeldsen},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.25343},
  eprint = {2609.25343},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.25343},
}

TY  - UNPB
TI  - Asteroseismology and interferometry of the F7V spectroscopic binary χ Draconis A in the TESS CVZ
AU  - Jonatan Rudrasingam
AU  - Mikkel N. Lund
AU  - Frank Grundahl
AU  - Arnab Chowhan
AU  - Timothy R. Bedding
AU  - Poul E. Nissen
AU  - Aldo Serenelli
AU  - Joel M. J. Ong
AU  - Jeppe S. Thomsen
AU  - Yaguang Li
AU  - Eva Panetier
AU  - Sarbani Basu
AU  - Owen J. Scutt
AU  - Travis S. Metcalfe
AU  - Savita Mathur
AU  - Mark Lykke Winther
AU  - George T. Hookway
AU  - Benjamin J. S. Pope
AU  - Amalie Stokholm
AU  - Desmond H. Grossmann
AU  - Jens R. Larsen
AU  - Jørgen Christensen-Dalsgaard
AU  - Daniel Huber
AU  - Mads S. Fredslund
AU  - Timothy R. White
AU  - Paul G. Beck
AU  - Pere L. Pallé
AU  - Rafael A. García
AU  - Hans Kjeldsen
PY  - 2026
DA  - 2026/09/21
PB  - arXiv
DO  - 10.48550/arxiv.2609.25343
UR  - https://arxiv.org/abs/2609.25343
AB  - We present a detailed analysis of the asteroseismic main-sequence benchmark star χ Dra A in the TESS northern CVZ. We aim to derive stellar mass and radius from asteroseismic modelling of individual mode frequencies and test the asteroseismic mass and radius against an independent dynamical mass and interferometric radius measurement. We determined the dynamical mass of χ Dra using 618 radial velocity measurements obtained with the SONG telescope at Tenerife, and 53 relative astrometric measurements. With the PAVO beam combiner at CHARA, we obtained the interferometric radius of χ Dra A. We determined asteroseismic parameters from 16 sectors of 20-sec cadence TESS photometry. We determined T_eff=6277±30 K, [Fe/H] =−0.51±0.03 dex, and [α/Fe]=0.08±0.03 dex from the spectroscopic analysis. For the dynamical fit we obtained a mass of M_A=1.028 ± 0.004 M_⊙ for χ Dra A, and M_B=0.735 ± 0.003 M_⊙ for χ Dra B. Combining the derived interferometric angular diameter with dynamical parallax yields an interferometric radius of R_A = 1.159^+0.029_−0.028 R_⊙. In the TESS power spectrum, we identified 38 individual oscillating modes. Using these modes, we modelled the star with nine independent pipelines to test the resulting model mass and radius against our independently calculated mass and radius. All models yielded masses slightly lower than the dynamical mass. Using asteroseismic scaling relations, we found that scaling masses from corrected scaling relations best reproduce the dynamical mass. The combination of spectroscopy, interferometry, and asteroseismology has yielded precise results for the main component of the χ Dra system, making it one of the best-characterised main-sequence solar-like oscillators.
ER  -