I was taking shots of the 2017 eclipse using my D7200 camera with a 1000 ND filter. As I was going through the pictures after downloading them to a pc, I noticed that there's what appears to be a tiny light source present off to the side of the sun. I have circled it in the picture below. It is also present in the pictures during totality, which I took without the ND filter.
It doesn't seem like a camera or a lens artifact, since it showed up pretty consistently in different shot configurations, but I did not know that a 300 mm zoom with an 1000 ND filter could capture a light source besides the sun and the moon in full day light. If it is not an artifact, what could be the source of this light?