Actual duration of the detected transients

Determine the actual temporal durations of the fast transient events detected on the Hamburger Sternwarte Doppel-Reflektor 0.6-m photographic plates from the APPLAUSE archive, in order to infer their true apparent magnitudes relative to the plate exposure times and assess whether they are brief flashes or long-duration sources.

Background

The study reports eleven fast transient events identified on archival photographic plates taken with the Hamburger Sternwarte Doppel-Reflektor 0.6-m telescope. Reported magnitudes assume the transients were exposed for the full plate exposure time, but if the events are short-lived flashes their true brightness would be significantly higher.

Because the analysis is based on two exposures per field separated by minutes and the events are single-plate detections, the temporal duration of each individual transient is not constrained by the dataset, making it a key unresolved parameter for physical interpretation.

References

However, we do not know anything about the actual duration of each transient. The magnitudes in Table \ref{table:table_transients} assume that the transient behaved like a star, that is, was exposed by the same exposure time everything else on the plate was.

— Fast Astronomical Transients in Archival Photographic Plates: Using optical aberrations as a tool for discerning real images, from plate artifacts  (2606.08319 - Busko, 6 Jun 2026) in Section Results