Asteroseismic Phase Modulation Detects 1.8 Solar-Mass Minimum Companion to δ Scuti Star TIC 160582982

The analysis combines phase-modulation timing of six independent p-modes with frequency-modulation solutions for the two strongest modes, both converging on P_orb = 89.29 d, e = 0.54, and K1 = 42.2 km s^{-1}. MIST isochrones fitted to atmospheric parameters and SED give a 1.93 solar-mass primary; the resulting mass function places the unseen secondary above 1.8 solar masses even at edge-on inclination. Absence of photometric or spectroscopic signatures of a second main-sequence star favors a compact object.

This approach extends the FM/PM technique previously validated on Kepler δ Scuti and γ Dor hybrids to TESS data, offering a pathway to detect quiescent compact companions that evade both radial-velocity and transit surveys. It directly links asteroseismology to the formation channels of neutron-star and black-hole binaries that may later merge as gravitational-wave sources.

The non-eclipsing geometry and lack of secondary lines leave the exact mass and nature uncertain; the formal minimum mass could still accommodate a massive white dwarf if inclination is low. Phase-resolved high-resolution spectroscopy over the next two seasons is required to break the inclination-mass degeneracy and test for any weak accretion signatures.