I was having a bbq with family in my garden in south london. at first we witnessed what we thought was jupiter pulsing, at times it pulsated brightly, then would be invisible for a time. we then realised that it could not be a planet as it was moving slowly across the sky in a southwest to northeast direction, it appeared very very high, could it be an object reflecting the sun? it seemed to be pulsating fairly randomly. it was hard to tell if it’s flight path was straight or not. i went to front of my house and i filmed the object with my ipad, in reviewing the footage, it appears to double pulsate on one ocasdion when slowed down. i managed to frame the object in the telegraph wires outside my house, which gives a perspective. the event lasted maybe 30 or 40 mins. the light is iniatially a little difficult to see it appears on frames 25-26, upper mid screen, on frame 30 it appears to double blink, hopefully there is a video expert out there who can edit and highlight the object.