Destruction of Long-Period Comets

Abstract

We identify a sample of 27 long-period comets for which both non-gravitational accelerations and Lyman-alpha based gas production rates are available. Seven of the 27 comets (i.e. 25 percent) did not survive perihelion because of nucleus fragmentation or complete disintegration. Empirically, the latter nuclei have the smallest gas production rates and the largest non-gravitational accelerations, which are both indicators of small size. Specifically, the disintegrating nuclei have a median radius of only 0.41 km, one quarter of the 1.60 km median radius of those surviving perihelion. The disintegrating comets also have a smaller median perihelion distance (0.48 au) than do the survivors (0.99 au). We compare the order of magnitude timescale for outgassing torques to change the nucleus spin, tau, with the time spent by each comet in strong sublimation, Dt, finding that the disrupted comets are those with tau < Dt. The destruction of near-Sun long-period comets is thus naturally explained as a consequence of rotational break-up. We discuss this process as a contributor to Oort's long mysterious ``fading parameter''.

arXiv commentAJ in press, 3 tables, 4 figures

References in corpus (9)

• A Survey of Water Production in 61 Comets from SOHO/SWAN Observations of Hydrogen Lyman-alpha: Twenty-One Years 1996-2016
• Cometary Activity Begins at Kuiper Belt Distances: Evidence from C/2017 K2
• Outburst and Splitting of Interstellar Comet 2I/Borisov
• Physical Properties of Asteroids in Comet-like Orbits in Infrared Asteroid Survey Catalogs
• Water Production Activity of Nine Long-Period Comets from SOHO/SWAN Observations of Hydrogen Lyman-alpha: 2013-2016
• Systematics and Consequences of Comet Nucleus Outgassing Torques
• Disappearance of Comet C/2010 X1 (Elenin): Gone with a Whimper, not a Bang
• Water Production Rates from SOHO/SWAN Observations of Six comets: 2017-2020
• Discovery statistics and the 1/a-distribution of long-period comets detected over the 1801-2017 period

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• Secular brightness curves of 272 comets
• Seasonally Varying Outgassing as an Explanation for Dark Comet Accelerations
• Fitting the Light Curve of 1I/`Oumuamua with a Nonprincipal Axis Rotational Model and Outgassing Torques
• Borderline hyperbolic comet C/2021 O3 (PANSTARRS) was fading as it approached the Sun
• Great comet C/2023 A3 (Tsuchinshan-ATLAS): dust loss before perihelion
• Splitting of Long-Period Comet C/2018 F4 (PANSTARRS)