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arXiv · 2507.15896

On the Image Profiles of Transients in the Palomar Sky Survey

Beatriz Villarroel·Enrique Solano·Geoffrey W. Marcy
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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.

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Beatriz Villarroel, Enrique Solano, Geoffrey W. Marcy. 2025-07-21. On the Image Profiles of Transients in the Palomar Sky Survey. https://arxiv.org/abs/2507.15896

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