On the Image Profiles of Transients in the Palomar Sky Survey
Solar and Stellar Astrophysics
2025-07-23 v1 High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
Abstract
The VASCO project has discovered groups of short-lived transients on historical photographic plates that lack conventional explanation. Hambly & Blair (2024) examined nine such transients reported by Villarroel (2021) and found that they exhibit narrower, rounder profiles, attributing this to emulsion flaws. However, well-established optical principles and atmospheric physics imply that unresolved flashes lasting less than a second naturally appear sharper and more circular than stellar images, particularly on long-exposure plates where stars are significantly blurred by seeing and tracking errors. Such profiles are an expected consequence of sub-second optical flashes, making their findings consistent with the transient interpretation.
Cite
@article{arxiv.2507.15896,
title = {On the Image Profiles of Transients in the Palomar Sky Survey},
author = {Beatriz Villarroel and Enrique Solano and Geoffrey W. Marcy},
journal= {arXiv preprint arXiv:2507.15896},
year = {2025}
}