The edge of the Milky Way's star-forming disc: Evidence from a 'U-shaped' stellar age profile. - Fiteni, Karl; Anderson, Stuart Robert; Debattista, Victor. P.; Caruana, Joseph; Amarante, João A. S.; Gough-Kelly, Steven; Eyer, Laurent; Beraldo e Silva, Leandro; Khachaturyants, Tigran; Cuomo, Virginia (Astronomy & Astrophysics / Astronomie et Astrophysique, 2026)