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Professor Stephen A Eales

Professor Stephen A Eales

Head of Astronomy Group
Cardiff Hub for Astrophysics Research and Technology (Co-Director)

School of Physics and Astronomy

+44 (0) 7775 871 691
N/2.19, Queen's Buildings - North Building, 5 The Parade, Newport Road, Cardiff, CF24 3AA
Available for postgraduate supervision


I am an astronomer who writes about astronomy. In my day job, I carry out research into the origin and evolution of galaxies, using telescopes all around the world and in space. After originally doing a PhD in radio astronomy, I have spent much of my career using telescopes that observe in the submillimetre waveband, the last of the electromagnetic wavebands to be opened up for astronomy (the 'final frontier'). In my other life, writing, I try not just to describe the discoveries we have made about the universe, cool those there are, but the messy human stories of how these discoveries were made.


2019:             Visiting Fellow, Clare Hall, Cambridge University

2013-present: Head of Astronomy Group, Cardiff University

2004-present: Professor, Cardiff University

2000-2004:     Reader, Cardiff University

1998-2000:     Senior Lecturer, Cardiff University

1994-1998:     Lecturer, Cardiff University

1990-1994:     Assistant Professor, University of Toronto

1989-1990:     Research Fellow, Space Telescope Science Institute

1986-1989:     Research Fellow, Institute for Astronomy, University of Hawaii

1981-1986:     PhD student, Clare Hall, Cambridge

1978-1981:     BA at Emmanuel College, Cambridge University

Honours and awards

2015: Herschel Medal from the Royal Astronomical Society

Professional memberships

Fellow of the Royal Astronomical Society






































  • Eales, S. A., Wynn-Williams, C. G. and Beichman, C. A. 1987. VLA observations of a sample of galaxies with high far-infrared luminosities. Presented at: Star formation in galaxies, Pasadena, CA, 16-19 June 1986 Presented at Lonsdale Persson, C. J. ed.Star Formation in Galaxies; Proceedings of a Conference Held at the California Institute of Technology, Pasadena, California, June 16-19 1986. NASA Conference publication Washington DC: National Aeronautics & Space Adminstration pp. 531-536.
  • Eales, S. A., Becklin, E. E., Wynn-Williams, C. G., Hodapp, K., Capps, R. W. and Simons, D. A. 1987. Observations of luminous IRAS galaxies with an infrared array. Presented at: Infrared astronomy with arrays : Workshop on Ground-based Astronomical Observations with Infrared Array Detectors, Hilo, Hawaii, 24-26 March 1987 Presented at Wynn-Williams, C. G., Becklin, E. E. and Good, L. H. eds.Infrared astronomy with arrays : proceedings of the Workshop on Ground-based Astronomical Observations with Infrared Array Detectors : University of Hawaii at Hilo, 24-26 March 1987. Honolulu, Hawaii: University of Hawaii, Institute for Astronomy pp. 345-349.
  • Eales, S. A., Becklin, E. E., Hodapp, K., Simons, D., Wynn-Williams, C. G. and McLean, I. S. 1987. The near-infrared structures of the centers of luminous IRAS galaxies and Seyfert galaxies [Abstract]. Bulletin of the American Astronomical Society 20, pp. 1067-1068.





I currently teach the second of our first-year maths courses

Research Interests

Galaxies are assemblies of stars that range in size from the tiny dwarf galaxies attached to our galaxy, which contain only a few thousand stars, to the giant galaxies at the centres of rich clusters, which sometimes contain over one trillion stars. My main research goals are to understand these fascinating objects, which are made up of stars, gas and dark matter - in particular how they were formed in the first place and how they and the universe have changed together during the 14 billion years since the big bang. Much of the light from these objects, in particular during the first billion years after their birth, is hidden by cosmic dust, tiny solid particles in interstellar space. In my research I therefore make a lot of use of submillimetre telescopes, such as the Herschel Space Observatory and the Atacama Large Millimetre Array, which effectively allow us to peer through the dust. I am also interested in many other research fields in astronomy, ranging from ones such as the measurement of the universe's basic properties (the cosmic parameters) in which I am actively involved to ones such as exoplanets and astrobiology in which I am not an active participant but an enthralled onlooker.

Current Research Projects

  • I was the co-leader of the largest Herschel survey of the extragalactic universe, the Herschel ATLAS. Although we have now released our images and catalogues to the worldwide astronomy community, my research team is still working on many projects with this magnificent dataset, include a project to find all the galaxies producing the submm emission in the hundreds of thousands of sources detected in our survey.
  • I am using ALMA to study the gravitationally-lensed sources discovered with Herschel, with the aims of using the magnification provided by the lenses to study the gas and the stars in these galaxy-building events.
  • The first submillimetre telescope was commissioned in 1987, but after 30 years of submillimetre astronomy we still do not have a submillimetre image of the nearest big spiral galaxy, the Andromeda Galaxy, because of the difficulty of getting an image of an object that covers such a large area of sky. My research team is leading an international project to produce the first high-fidelity submillimetre images of Andromeda, which will allow us to study the dust and the stars in a galaxy other than our own with unprecedented resolution.
  • With Herschel we could routinely detect galaxies out to a redshift of six, less than one billon years after the big bang. We aim to go even further back in time with MUSCAT, a new millimetre telescope that has been built by the Cardiff Astronomy Instrumentation Group. Once the pandemic is over, this camera will be shipped to the Large Millimetre Telescope in Mexico where we will use it to detect the first generation of galaxies, only a few hundred million years after the big bang, as well as protoclusters, the first large-scale assemblies of galaxies that will eventually, after ten billion years or so, become the rich clusters of galaxies we see around us today.


I am currently supervising two PhD students: Gayathri Eknath and Bradley Ward