The consequences of a nearby supernova on the early solar system

¹ Leiden Observatory, Leiden University, PO Box 9513, 2300 RA, Leiden, The Netherlands
e-mail: spz@strw.leidenuniv.nl
² Centrum Wiskunde & Informatica, Science Park 123, 1098 XG Amsterdam, The Netherlands
³ Department of Astrophysics/IMAPP, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen, The Netherlands
⁴ Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, 1121 Budapest, Hungary

Received: 6 October 2017
Accepted: 10 April 2018

Abstract

If the Sun was born in a relatively compact open cluster (half-mass radius ≲3 pc) with ≳10³ stars, it is quite likely that a massive (≳10 M_⊙) star was nearby when it exploded in a supernova. The repercussions of a supernova can be rather profound, and the current solar system may still bear the scars of this traumatic event. The truncation of the Kuiper belt and the tilt of the ecliptic plane with respect to the Sun’s rotation axis could represent such signatures. We simulated the effect of a nearby supernova on the young solar system using the Astrophysical Multipurpose Software Environment (AMUSE). Our calculations are realized in two subsequent steps in which we study the effect of the supernova irradiation on the circumstellar disk and the effect of the impact of the nuclear blast-wave which arrives a few decades later. We find that the blast wave of our adopted supernova exploding at a distance of 0.15–0.40 pc and at an angle of 35°–65° with respect to the angular-momentum axis of the circumsolar disk would induce a misalignment between the Sun’s equator and its disk to 5.°6 ± 1.°2, consistent with the current value. The blast of a supernova truncates the disk at a radius between 42 and 55 au, which is consistent with the current edge of the Kuiper belt. For the most favored parameters, the irradiation by the supernova as well as the blast wave heat the majority of the disk to ≳1200 K, which is sufficiently hot to melt chondrules in the circumstellar disk. The majority of the planetary system may have been affected by a nearby supernova. Some of its repercussions, such as truncation and tilting of the disk, may still be visible in the current planetary system topology. The amount of material from the supernova blast wave that is accreted by the circumstellar disk is too small by several orders of magnitude to explain the current abundance of the short-lived radionuclide ²⁶Al.