Reasons an Object is Killed in the Final Verification Pass.

These descriptions shows some of the more commmon reasons an object is tossed in the final verification stage. The top entries are roughly speaking the most frequent offenders.

1. One or more of the linked object set is a Cosmic Ray Strike. These look different from everything else in the image and are usually much, much sharper than all other images. Most of the time you see this from simple visual inspection. Other clues that help verify the diagnosis are: 1) FWHM is too small (ie., < 1), 2) Object magnitude doesn't repeat well, 3) Object magnitude is much brighter than plate limit but the image looks faint, 4) Object looks exactly like all the other cosmic ray strikes in the image that were not linked to something else.

2. One (or more) of the linked objects is actually a field star. Yes, it can happen that a real object sits on top of a field star and should be marked. However, the brightness of the field star and object should be consistent with other stars in the field.

3. One (or more) of the linked objects is trailed and trailed in a direction not in the direction of linked motion. In our survey data, KBOs should not be trailed at all. Main-belt asteroids will trail and the direction of trailing should be consistent with the pair of objects marked.

Reasons an Object is Flagged with ? in the Final Verification Pass.

These objects are for some reason dubious but not enough so that it can be dismissed outright. However, an object so marked probably won't get followed up unless it generates a good orbit and we have enough time to chase it down after all the other certain objects are completed.

1. Object is quite real in one image but the other image is not consistent with the above criteria. Odds are that this is a main-belter than you can't find the mate for and you've linked the good image to an image flaw.

Other oddball mis-identifications.

Object 26072603 (now deleted) from field F00117, 2000/08/26 was a Jupiter Trojan in the red image and a piece of a satellite trail in the cyan image. This was really confusing at first. The satellite trail is not precisely linear and right next to the red image there is a cyan brightening from the satellite that is not quite in line with the trail. It must be some protuberance on a spinning spacecraft that we were actually resolving. It wasn't until I noticed the cyan mate to the Trojan that I was able to understand the image. I was very suscpicious given the proximity to the trail. The fact that this was a Trojan made the red image tighter than it would have been were it a main-belt asteroid. The moral on this story is that if the image looks strange, look at it harder for more clues. There's no way anyone could look at this at first and not initially consider it to be confusing.