Weird bright UFO caught over Andover, UK

One day of October 2016, a witness was at work in Andover (in Hampshire County, United Kingdom). During a tea break, he has noticed an unusual and unidentified bright light in the sky.

Witness report:

On 4th October, 2016, I was at work and went outside for tea break. A group of us were chatting and we noticed a plane in the sky. It was a clear day. I noticed a small shiny object ahead of the plane and pointed it out to the other people there and said it didn't look like a plane, you couldn't see the wings and there was no vapour trail. I thought it was strange so I took some photos as I thought I could enlarge the photo to see the object better. I took 3 photos before I lost sight of the object due to a building. The object seemed to increase the distance between it and the plane very slightly but I think this was due to the angle of vision as it crossed my line of sight. I wondered if it was a UFO and after looking at the photos and still not being able to see wings I am curious.