CGCS 6306, another X-ray-emitting asymptotic giant branch star confirmed to be a symbiotic binary Jaroslav Merc, Martín A. Guerrero, Jesús A. Toalá and Roberto Ortiz A&A, 699 (2025) A117 Published online: 02 July 2025 DOI: 10.1051/0004-6361/202554671