Professor Jørgen Christensen-Dalsgaard has been a leading figure in international research into stellar physics for many years. He has now been awarded the Carlsberg Foundation’s Research Prize in natural sciences for his ground-breaking research.
Jørgen Christensen-Dalsgaard is a leading figure in international research into stellar physics, and he has been highly recognised for many years. He has comprehensive knowledge and considerable experience with both theoretical and observational sides of the study of stars and planets. Based on this, he has not only contributed to, but has also led major areas of the development this field of research has experienced in recent decades.
With a focus on organising targeted international collaboration, taking part in major space- and ground-based observation projects, and building up a strong national research centre at Aarhus University, Professor Christensen-Dalsgaard has placed Denmark as a leading player in the study of the structure and development of stars, and the study of specific properties of planets in orbit around the stars.
His starting point has been the development of helio- and asteroseismology, which he has used as the main tool to gather information about the interior of the stars. Helio- and asteroseismology are based on measuring the vibration frequencies for the small variations that occur in the stars and the Sun, and which arise when sound waves act as standing waves in the entire star.
One of the major results of Professor Christensen-Dalsgaard’s work is the building up of a theoretical reference model that is currently used internationally to make comparisons between studies of the Sun by different teams of researchers, and as a reference for the study of other Sun-like stars.
A natural consequence of the success with studying the Sun has been carrying out the same type of analysis for the stars. The immediate problem in relation to this is that the stars shine several billion times weaker than the Sun, and the study of the stars – asteroseismology – was therefore initially about being able to measure the signals from the vibrations in the stars at all.
To prepare for these observations, Professor Christensen-Dalsgaard very early predicted the size of these vibrations. Under his leadership in 1995, researchers succeeded for the first time in measuring Sun-like vibrations in another star than the Sun and, with this observation, a new type of oscillation was measured and interpreted correctly. This led to a breakthrough in the study of the interior of the stars.
Due to his knowledge and experience, Professor Christensen-Dalsgaard was invited in 2006 to take part in NASA’s Kepler Mission, as the only non-American co-investigator. He was asked to develop the entire asteroseismology programme for this mission, the main purpose of which was to find Earth-like and principally habitable planets around other stars than the Sun.
In Professor Christensen-Dalsgaard’s spirit, part of the programme was organised as a major international research activity under the name Kepler Asteroseismic Science Consortium (KASC), which now has 550 affiliated researchers. Another part of the work involves measuring properties of the stars around which the Kepler Satellite has found planets. This work is undertaken by a smaller team of researchers at Aarhus University.
Professor Dalsgaard’s success in organising asteroseismology for the Kepler Mission led to his involvement as co-investigator of NASA’s new planetary mission – the Transiting Exoplanet Survey Satellite (TESS). This was approved in early April 2013 and will be launched in 2017. The fact that Professor Christensen-Dalsgaard was selected to lead this activity is an indication of the considerable international acknowledgement he enjoys and his ability to gather scientists and organise their research.
As regards research in Denmark, Professor Jørgen Christensen-Dalsgaard has been awarded major research grants in recent years by the VILLUM Foundation, the Carlsberg Foundation, the European Research Council and the Danish National Research Foundation. This has strengthened his field of research in Denmark in general, and at Aarhus University in particular.
These research grants have been consolidated in the Stellar Astrophysics Centre at Aarhus University – a centre that has formal collaborative agreements with the Massachusetts Institute of Technology (MIT) and NASA’s Ames Research Center (USA), as well as universities in Birmingham (UK), Freiburg (Germany) and Sydney (Australia).
As part of the Stellar Astrophysics Centre, Professor Christensen-Dalsgaard has accumulated funds to make a start on the construction of a global network of telescopes called the Stellar Observations Network Group (SONG). The first SONG telescope is currently being tested at the Izaña Atmospheric Observatory on the Spanish island of Tenerife. More telescopes are expected to be built in the coming years (including a collaboration with China) and SONG will be an optimal supplement to Kepler and TESS, especially as regards following up on measurements of the stars around which Kepler and TESS find planets.
The Carlsberg Foundation’s Research Prize supports active researchers in Denmark and abroad who have made crucial contributions to basic research, and who have gained considerable scientific recognition. The Carlsberg Foundation was set up in 1876 by the brewer J. C. Jacobsen. The foundation is a main investor in the Carlsberg Group and awards DKK 200 million each year to activities of benefit to society, with particular focus on outstanding basic research.
The prize was presented by HRH Crown Princess Mary at a ceremony in the Central Hall of the Ny Carlsberg Glyptotek on 17 September 2013.
See the Carlsberg Foundation’s video about Jørgen Christensen-Dalsgaard (in Danish only).
Read more about the Carlsberg Foundation here.