FR 7873 then FR 498 at Madrid
Palermo → Madrid → London Stansted
Timetable, Madrid time
12:55FR 7873 from Palermo at the gate
10:25FR 498 to London Stansted leaves the gate
21 h 30 apart on the timetable, overnight
FR 498 leaves 21 h 30 after FR 7873 arrives on the timetable: more than half a day, so not a connection we count.