Radioactivities from Stars to Solar Systems

Nearby supernova roasted infant Solar System

There are a number of peculiarities related to the Solar System. For instance, the planets move in a plane, the ecliptic, which makes an angle of 5.6 degrees with the equatorial plane of the Sun. In addition, the disk of the planets is truncated at about 45au, which is much smaller than the protoplanetary disks observed around other stars. Both phenomena can be explained by a supernova explosion very near the Solar Systems when it was in its infancy.

Researchers from Leiden University and the Hungarian Academy of Sciences have investigated the consequences of a nearby supernova explosion on the Solar System. Such explosions occur only in the most massive stars, which are rare. When the Sun was barely born and the planets had not yet formed the Solar System was probably the member of a cluster of a few 1000 stars. It is quite likely that one of these stars exploded nearby resulting in profound consequences for the entire Solar System.

The researchers calculated the consequences of such a supernova on the Solar System. The calculations ware performed with the Astronomical Multipurpose Software Environment, a special multi-scale and multi-physics simulation environment designed and built at Leiden Observatory. Using this computational environment the researchers ware able to constraint he distance and direction of this nearby supernova. They conclude that when a supernova exploded at a distance of 0.15 to 0.40 parsec and at an angle of 35-60 degrees with respect to the rotation axis of the protoplanetary disk, the current disk tilt of 5.6 degrees and its truncation at 45au are explained.

"It was amazing that our results lead to such strong conclusion with respect to the disk tilt as well as to its truncations.", sais research leader Portegies Zwart from Leiden Observatory. "The consequences are rather profound, imagine that a supernova exploded today at such a distance. We then would first see the bright star outshining the Sun appearing for about 100 days, and about 30 years later the nuclear blastwave of the supernova sterilizes the planet." "Luckily this is very unlikely to happen today", sais Pelupessy currently working as integrator at the Netherlands E-science Center, "the nearest star that experiences a supernova relatively soon is Betelgeuse, but at distance of more than 200parsec this will give a nice fireworks on the sky without but the Solar System will hardly be affected."

"Apart from tilting and truncating the protoplanetary disk, a nearby supernova may also have profound consequences for the chemical evolution of the Solar System", says Maria Lugaro researcher at the centre for astronomy and earth sciences of the Hungarian Academy of sciences. "The injection of short-lived radionuclides, such as 26Al and 60Fe has been observed in the Solar System although it is still unclear if such a nearby supernova is the source of these materials. The episodal heating to high temperatures due to a nearby supernova, however, may have had a profound influence on the chemical and mineralogical structure of early Solar system materials. The unexplained glass-like droplets in the oldest meteorites could be the result of melting parts of the gaseous disk before the planets formed. A nearby supernova in the Solar system's infancy could have been responsible for this phenomenon.

The findings of the team are in press in Astronomy and Astrophysics.

| ArXiv - EN |