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arXiv · 2512.01169

Disintegration of Long-period Comet C/2019 Y4 (ATLAS). II. Post-Perihelion Remnant Recovery

Salvatore A. Cordova Quijano·Quanzhi Ye·Michael S. P. Kelley
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Abstract

We present an investigation into the fate of disrupting near-Sun comet C/2019 Y4 (ATLAS). Imaging observations with the Lowell Discovery Telescope (LDT), obtained 3--5 months after the reported disruption and the last sighting, constrained the primary component C/2019 Y4-B to an absolute magnitude of $H>20.5$ or a diameter of $D<0.5$~km (assuming a geometric albedo of 0.04) at an outbound heliocentric distance of 2.71~au. A search of shallower data obtained from the Zwicky Transient Facility (ZTF) survey, conducted when components A and B receded from 2.5 to 2.9~au from the Sun, yielded no detections, suggesting that the fragments had either ceased to exist or were not substantially active during this period. The uncertain fate of C/2019 Y4 highlights the challenge in understanding the state of presumably disrupted comets. Our review of six other presumably disrupted long-period comets reveals that negative confirmations were not reported for half of them, leaving their disruption presumptions inconclusive.

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Salvatore A. Cordova Quijano, Quanzhi Ye, Michael S. P. Kelley. 2025-12-01. Disintegration of Long-period Comet C/2019 Y4 (ATLAS). II. Post-Perihelion Remnant Recovery. https://arxiv.org/abs/2512.01169

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