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It is with great regret that we announce that Professor of Astronomy, John Dyson, passed away on 3 Feb 2010. John Dyson was a theoretician working at the interface with observational astronomy. He came to Leeds in 1996 from Manchester, though as a Leeds man and enthusiastic supporter of Leeds United, he was returning home. He was internationally renowned for his work on bubbles in the cosmos blown by the winds of stars and active galactic nuclei.

John was Dean for Research from 1998-2000 and Head of Physics and Astronomy from 2000-2003. He retired in 2006 but continued to work as a Research Professor. Notes in his file suggest that he instigated the change in the name of our department to include Astronomy. Quite exceptionally, he had more than 50 co-authors on his publications. Those of us who were fortunate enough to know John Dyson will sorely miss him, not least his dry humour and ready wit. He is survived by his wife Rita, 4 children and 7 grand-children.

Image credits: HH1/HH2 - J. Hester (ASU), WFPC2 Team, NASA; Cygnus A - C. Carilli, NRAO.

The top image shows a jet from a young star, while the bottom image shows a jet from an active galaxy. While there are underlying similarities in the physics of these objects, their scales are very different.

The Herbig Haro 1 and 2 bipolar outflow (top), with a length of around a lightyear from tip to tip, originates on a star having an age of around a million years and a mass comparable to that of the Sun. Leeds has major research programmes in star formation, the discs around stars, and how outflows from stars and other astronomical sources affect the surrounding environments.

The double radio lobes of Cygnus A (bottom) which span over 500,000 lightyears, are fed by jets of energetic particles formed near a 2.5 billion solar mass black hole. Similar jets are amongst the sources of very high energy gamma rays observed by the group and may be sites for the acceleration of the most energetic cosmic rays. The group plays a leading role in the Auger Observatory built to detect the sources of such cosmic rays.

Further details of the research conducted by the Leeds group can be found under "research" in the navigation bar.