Skip to main content

Importance of Supernovae in the Enrichment of Planetary Systems

Figure: Called the Veil Nebula, the debris is one of the best-known supernova remnants, deriving its name from its delicate, draped filamentary structures. This view is a mosaic of six Hubble pictures of a small area roughly two light-years across, covering only a tiny fraction of the nebula’s vast structure. Credit: NASA/ESA/Hubble Heritage Team


The presence and abundance of short lived radioisotopes in chondritic meteorites implies that the Sun formed in the vicinity of one or more massive stars that exploded as supernovae (SNe).



Massive stars are more likely to form in massive star clusters (>1000 M⊙) than lower mass clusters. However, photoevaporation of protoplanetary discs from massive stars and dynamical interactions with passing stars can inhibit planet formation in clusters with radii of ∼1 pc.

In a recent paper (Nicholson & Parker 2016) the authors investigate whether low-mass (50 - 200 M⊙) star clusters containing one or two massive stars are a more likely avenue for early Solar system enrichment as they are more dynamically quiescent.

They analyze N-body simulations of the evolution of these low-mass clusters and find that a similar fraction of stars experience supernova enrichment than in high mass clusters, despite their lower densities.

This is due to two-body relaxation, which causes a significant expansion before the first supernova even in clusters with relatively low initial densities.  However, because of the high number of low mass clusters containing one or two massive stars, the absolute number of enriched stars is the same, if not higher than for more populous clusters.

Their results show that direct enrichment of protoplanetary discs from supernovae occurs as frequently in low mass clusters containing one or two massive stars (>20 M⊙) as in more populous star clusters (1000 M⊙).

This relaxes the constraints on the direct enrichment scenario and therefore the birth environment of the Solar System.

  • Nicholson & Parker 2016 (accepted in MNRAS) - Supernova enrichment of planetary systems in low-mass star clusters (arXiv)
Etichette:

Comments

Post a Comment

Popular posts from this blog

ORBITAL PERIODS OF THE PLANETS

For orbital period generally we refer to the sidereal period, that is the temporal cycle that it takes an object to make a full orbit, relative to the stars. This is the orbital period in an inertial (non-rotating) frame of reference (365,25 days for the earth).
Post a Comment
Read more

A Sapphire Super-Earth

Twenty-one light years away, in the constellation Cassiopeia, a planet by the name of HD219134 b orbits its star with a year that is just three days long. With a mass almost five times that of Earth, it is what is known as a super-Earth. Unlike our planet, however, these super-Earths were formed at high temperatures close to their host star and contain high quantities of calcium, aluminum and their oxides – including sapphire and ruby. HD219134 b is one of three candidates likely to belong to a new, exotic class of exoplanets. These objects are completely different from the majority of Earth-like planets. They have 10 to 20 percent lower densities than Earth. Researchers looked at different scenarios to explain the observed densities. For example, a thick atmosphere could lead to a lower overall density. But two of the exoplanets studied, 55 Cancri e and WASP-47 e, orbit their star so closely that their surface temperature is almost 3,000 degrees and they would have lost this ...
Post a Comment
Read more

CONTAMINATION BY SUPERNOVAE IN GLOBULAR CLUSTERS

Credit: ALMA (ESO/NAOJ/NRAO)/Alexandra Angelich (NRAO/AUI/NSF) Only a small amount of the supernovae products remains trapped within globular clusters and this "catch" only occurs in the most massive cases (mass cluster ≥ 10^6 solar masses).
Post a Comment
Read more