Stars, dust and gas: the life cycle of galaxies

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The life cycle of matter describes the evolution of a galaxy. Collapsing clouds in the interstellar medium leads to star formation. This locks much of the gas reservoir of the galaxy away, in stars. At the end of their life, stars eject much of their gas back into space, either as a supernova, or through an extreme wind - our Sun will do the latter. The ejecta contain the products of nuclear burning and enrich the gas with elements such as carbon and oxygen. They also produce solid particles, called dust. The ejecta become part of the next generation of star formation, changing the appearance and evolution of these stars. This cycle of matter has been called the ecology of a galaxy. The dust also becomes incorporated in the cycle of matter and in the star formation, initiate the formation of planets. In our solar system, some dust grains have been found which date from the formation of the solar system. Their composition can be used as a fingerprint to identify the type of dying star from which they formed. We study this life cycle of matter: the formation of stars, their death, and the formation of planetary systems, making use of telescopes such as e-Merlin, ALMA, the VLT and the JCMT. We will idenitfy the type of stars from whose death gave rise to our solar system.