What was this?

Hello,

I am a new user and I'm not sure if this is the correct category, but let's try :)

I am living south of Bremen (North Germany, 53.025 / 8.858). Can anybody tell me what crossed the sky at 11am (CEST+1 / GMT+2) today? The noise was very loud, it sounded like a very large Jet. I didn't see anything on Flightradar24. Few seconds later an A380 coming from Northeast crossed the sky, but the noise definately did not belong to the A380.

Does anybody know?

thank you,
thermik.