Destruction of Long-period Comets

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