Asteroidal activity amongst meteor datasets: Confirmed new "rock-comet" stream and search for a tidal disruption signature

Abstract

Asteroid activity (e.g., thermo-mechanical breakdown, impacts, rotational shedding, tidal disruption, etc.) can inject meteoroids into near-Earth space and leave detectable signatures in orbit catalogs. We searched for such recent signatures using orbit-similarity statistics and explicit null-hypothesis testing applied to shower-removed, asteroidal video-meteor datasets. Our sample comprises 235{,}271 meteors and fireballs from four all-sky video networks (GMN, CAMS, EDMOND, and SonotaCo). For meteors we use the geocentric dissimilarity criterion $D_N$ and construct KDE-based sporadic null realizations to evaluate (i) global cumulative similarity distributions and (ii) localized $D_N$-conditioned ($D_N<0.015$) pair-excess maps in the $(U,\lambda_\odot)$ plane; we additionally apply DBSCAN ($\epsilon=0.03$, $\mathrm{min\_samples}=2$) to isolate the coherent, statistically significant structures. We find no survey-consistent, stream-like signature in the Earth-like, low-inclination region expected for a distinct \emph{recent} tidal-disruption family; instead, significant-bin membership implies, under our adopted detection thresholds and binning, a conservative combined upper limit of $\leq 53/235{,}271$ ($\leq 2.3\times10^{-4}$) for sporadic asteroidal meteors plausibly attributable to a detectable recent tidal-disruption-like contribution. In contrast, we confirm the detection of a new diffuse southern Virginid-region stream: GMN exhibits a local z-score of 6.32 relative to the KDE-null mean in the $U-\lambda_\odot$ phase space (global significance of 5.3~$\sigma$), with weaker supporting excess in SonotaCo and EDMOND. DBSCAN isolates $N=282$ members (243 GMN plus additional SonotaCo, CAMS, and EDMOND) on a low-perihelion, asteroidal orbit ($q=0.22\pm0.01$ au, $i=12.3^{\circ}\pm1.8^{\circ}$, $T_J=4.6\pm0.3$) consistent with near-Sun thermo-mechanical ``rock-comet'' activity.