Solar Twins and Possible Solutions of the Solar and Jupiter Abundance Problems

Implications of the recently discovered systematic abundance difference between the Sun and two collections of `solar twins' are discussed. The differences can be understood as an imprint on the abundances of the solar convection zone caused by the lock-up of heavy elements in the planets. Such a scenario also leads naturally to possible solutions of two other abundance peculiarities; 1) the discrepancy between photospheric abundances derived from accurate 3-D models of the solar photosphere and the abundance of heavy elements in the solar interior deduced from helioseismology, and 2) the abundance pattern of Jupiter, which can either--with great difficulty--be interpreted as a general and similar overabundance of both common elements such as carbon, nitrogen and sulphur and rare inert gases such as argon, krypton and xenon, or--much more simply--as an under-abundance of hydrogen.