Time-series spectroscopy combined with TESS photometry characterised AX Draconis as a semi-detached eclipsing binary with a 0.568-day orbit and identified four independent low-frequency signals consistent with gamma Doradus pulsation. It may be the shortest-period double-lined eclipsing system known with such a pulsator, while its evolutionary and mass-transfer history remains model-based inference.
Key findings
- The 0.568-day system has a total secondary eclipse. The primary rotates at 120±21 km/s with Teff 7,220±150 K. Component masses are 1.717±0.026 and 0.804±0.014 solar masses; radii 1.541±0.020 and 1.237±0.014 solar radii; luminosities 5.78±0.50 and 0.83±0.05 solar luminosities. Among 35 signals below 5 d−1, four independent frequencies match gamma Doradus pulsation.
Why this matters globally
Precise eclipsing-binary parameters can test pulsation models under tidal gravity, rapid rotation and mass transfer, conditions not captured fully by isolated-star models.
Thai researcher contribution
Pakakaew Rittipruk of the National Astronomical Research Institute of Thailand contributed to an international time-domain astrophysics collaboration, highlighting Thai participation in precision stellar research.
Limitations to consider
Pulsation classification and mass-transfer history depend on signal separation and binary modelling. Frequencies may be affected by orbital, rotational or instrumental effects, and the “shortest-period” claim is catalogue-dependent.