How does the Solar System Pipeline handle a very fast same-visit object spanning multiple Rubin detectors?

LienaDreams · June 28, 2026, 7:10pm

Hello,

I have a question for Solar System Pipeline experts.

I am seeing cases where a very fast object appears to cross multiple Rubin detectors within a single visit, producing several alerts with the same timestamp but different sky positions.

Example below has seven alerts across three detectors (118, 119, 126) line up perfectly in RA/Dec on the night of June 26, 2026, visit 2026062600737. Based on its flux, extendedness, trailLength, reliability score and cutouts it looks like the same object. But if interpreted as one moving object during a single exposure, the implied angular speed is extremely high (over 1000 deg/day).

Since a SkyBot/MPC search does not provide a consistent identification for these alerts, I am looking for a way to identify them, and, if possible, follow-up them with a telescope.

I understand that a meaningful orbit or velocity cannot be derived from alerts sharing the same timestamp, but I am curious how does the Rubin Solar System Pipeline treat these events? Have you found a practical way to identify or distinguish these events in the alert stream? Would an event like this be considered a many-point tracklet by the Solar System Pipeline, despite all seven alerts sharing the same timestamp?

Below are diaObjectId of these 7 alerts, their motion plot and cutouts

diaObjectId:
170591527057228257,
170591527057228205,
170591527053558166,
170591527053558053,
170591527053557997,
170591527053033643,
170591527053033605,

Motion plot

Cutouts

recoil77 · June 28, 2026, 8:35pm

I think this is probably not a Solar System object after all.

Since all seven detections come from the same visit / same timestamp, the line is most likely a single artificial object crossing multiple detectors during one exposure, rather than a many-point SSO tracklet.

Using the hard-trail detections, the visible span is about 2457.0 arcsec, or 0.683 deg. For a 30 s LSST exposure this gives roughly:

81.9 arcsec/s ≈ 1966 deg/day

In my Rubin alert data I see many tens of thousands observations, of similar same-visit linear events. On visit-level sky-position visualizations they often appear as long straight stripes crossing detectors. These have to be detected and filtered out at scale, otherwise they can easily contaminate moving-object candidate searches.

So I treat this as a likely satellite artifact, not as an SSO candidate for follow-up.

LienaDreams · June 28, 2026, 10:07pm

@recoil77 Thank you, Anton, yes, looks like a satellite, and it makes sense taking into account its speed and orbit. I also see many of these objects, so it’s good to know what they are. Now I can focus on more promising candidates.