Hello my name's lucas and i'm from nowy dwor mazowiecki, poland, a small town about 30 km (19 miles) from warsaw. i'm actually writing to you because on the night of 09.05.2018 i was taking long exposure (30 sec) photos with a friend of mine. suddenly, on one of the photos a strange object appeared. it wasn't visible to the naked eye, so without hesitation we took another shot and the object appeared on the photo again. we assumed that it could have been a speck of dust on either the lens or the camera image sensor so we had cleaned both, just to make sure we eliminated any potential distortions. then, we aimed the camera at a different part of the sky and nothing out of ordinary showed up on the pictures. however, when we moved the camera back to the previous part of the sky and took another two shots the mysterious object came into sight again but this time it changed its position and angle. i have no idea what that was that's why i thought i would ask you to take a look at the pictures. maybe you could analyse them? please find three out of four pictures of the object in .Jpeg format attached. unfortunately, the fourth picture was accidentally deleted. i'm also sending a shot of the same part of the sky in daylight, so you can see what the area actually looks like. what's more, by day, this part of the sky is busy with planes taking off from the nearby warsaw - modlin airport. the original images were taken in the raw format. best regards from poland