The weather has finally cleared up at Siding Spring observatory. We have been observing for about eight hours each night from the Anglo-Australian telescope (AAT) near Coonabrabran. The AAT is a 3.9-m telescope and is equipped with the University College of London high-resolution Echelle Spectrograph (UCLES). Using the spectra from UCLES we can measure the tiny oscillations on the surface of the solar-like star Procyon. We are collecting spectra of Procyon from Japan, USA, France, Spain, Chile and Australia. The aim is to get almost continuous observations of the star for a week or more. The measurements of the oscillations in the star will be used to probe the interior of the star in great detail. It is very much like geologists measuring earthquakes to learn about the layers below us. We call it asteroseisomlogy. Procyon is about 40% more massive than the sun. Actually, it is a binary star system comprising the evolved main-sequence star Procyon A and a white dwarf, Procyon B, which orbits the main star in about 40.8 years. Procyon B used to be the most massive star in the system, but it has already used up all its hydrogen fuel. As a consequence Procyon B has expelled its outer layers and now a hot core with a radius comparable to the earth is left. The white dwarf was discovered about 150 years ago in 1861 by von Auwers.

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