Size, Albedo, and Taxonomy of Asteroid (1201) Strenua from Stellar Occultation and ATLAS Photometry

Context. A multi-chord stellar occultation by (1201) Strenua observed on 26 April 2026 is combined with ATLAS c - and o-band photometry. Aims. We aim to determine the size and geometric albedo of Strenua and reassess its taxonomic classification. Methods. Four positive chords from a 47-station campaign across Indonesia were fitted within a Bayesian forward-modeling framework to derive an ellipse cross-section and equivalent diameter. ATLAS photometry was modeled using the H, G 1, G 2 phase-function system to determine band-specific absolute magnitudes, converted to H V, and combined with the occultation diameter to calculate geometric albedo and update taxonomy. Results. The chords yield semi-axes a' = 27.49+3.90-1.65 km and b' = 14.33+2.37-2.69 km (position angle 95.3+4.9-2.7 deg), giving an area-equivalent diameter D eq = 39.86+2.06-1.66 km. Photometric modeling gives H c = 11.50 plus or minus 0.05 mag (G 1,c = 0.81 plus or minus 0.08, G 2,c = 0.04 plus or minus 0.02) and H o = 11.29+0.02-0.03 mag (G 1,o = 0.94+0.03-0.05, G 2,o = 0.01 plus or minus 0.01), yielding H V = 11.46 plus or minus 0.05 mag. The resulting geometric albedo p V = 0.029 plus or minus 0.003 places Strenua among the darkest primitive asteroids, securely reclassifying it as P-class and resolving its legacy X-complex ambiguity.