BA 486 then LA 5783 at Barcelona
London Heathrow → Barcelona → Santiago de Compostela
Timetable, Barcelona time
18:30BA 486 from London Heathrow at the gate
12:00LA 5783 to Santiago de Compostela leaves the gate
17 h 30 apart on the timetable, overnight
LA 5783 leaves 17 h 30 after BA 486 arrives on the timetable: more than half a day, so not a connection we count.