The Heidelberg Joint Astronomical Colloquium series this winter semester 2025/26 takes place on Tuesdays at 16:30 at the large lecture hall (gHS), Philosophenweg 12. The colloquium is organised jointly by the Center for Astronomy at Heidelberg University (ZAH), the Max Planck Institute for Astronomy (MPIA), the Max Planck Institute for Nuclear Physics (MPIK), and the Heidelberg Institute for Theoretical Studies (HITS). For further information please contact Kathryn Kreckel (kathryn.kreckel@uni-heidelberg.de) or Eduardo Banados (banados@mpia.de).