Astrometric Overdensity of 543 High Proper Motion Stars in the Sagittarius Quadrant: Dynamical Footprint of a Local Quiescent 6.6 Msun Black Hole Remnant validated by Gaia DR3, VVV/VIRAC2, and LIGO O3 Data

We present a unified multi-wavelength astrometric investigation of 543 high proper motion stars in the Sagittarius Wow! region (RA 290.5 Dec -27.0). Gaia DR3 0.5° cone-search shows 4.36% overdensity vs 2-3% background. Cross-validated with VVV/VIRAC2 13-year infrared baseline (2010-2023) with mu 94-184 mas/yr. Corrected transverse velocity for primary outlier Gaia DR3 6765796873985981056: Vtan 46.4 km/s, Vtot 103.4 km/s. LIGO O3 10-day scan 0.11-18 Hz, Lambda 9.61, strain 0.8-2.2e-21, excludes >1000 Msun active perturber, confirms quiescent 6.6 Msun remnant.