This is my thought. I suspect these are asteroids. The tell is whether the stars show up on plates, say, a year later. If so, then they're not asteroids. Howev

This is my thought. I suspect these are asteroids. The tell is whether the stars show up on plates, say, a year later. If so, then they're not asteroids. However, that seems to have been ruled out in the Astronomical Journal article: "Given the exposure time of 45 minutes of the POSS-I E red image, if our object were an asteroid that quickly moved out of the field, it would have left a stripe (and not be point-like)." (Page 5) "The exposure time for the red image is about 50 minutes. If the object were an asteroid and was quickly moving through the field of the red image in a few minutes, then it would be elongated on the plate. However, this object is point-like. In addition, the candidate is anomalously red and not seen in the blue band, which further decreases the likelihood that it is an asteroid." (Page 13)