Mauri Valtonen is a Finnish

Finland

Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

 astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

 and professor at the University of Turku

University of Turku

The University of Turku , located in Turku in southwestern Finland, is the second largest university in the country as measured by student enrollment, after University of Helsinki. It was established in 1920 and also has faculties at Rauma, Pori and Salo...

. His fields of scientific interest include active galaxies, cosmology

Cosmology

Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...

, and the three-body problem

Three-body problem

Three-body problem has two distinguishable meanings in physics and classical mechanics:# In its traditional sense the three-body problem is the problem of taking an initial set of data that specifies the positions, masses and velocities of three bodies for some particular point in time and then...

.

Valtonen completed a Ph.D. from Cambridge University in 1975. He served as Director of Tuorla Observatory

Tuorla Observatory

Tuorla Observatory is the Department of Astronomy at the University of Turku, southwest Finland. Currently it is the largest astronomical research institute in Finland...

 from 1980 to 2002 and returned to this position again in 2007.

In 2008, Valtonen led a research team which argued that delay in the periodic outbursts from the nucleus of the active galaxy OJ 287

OJ 287

OJ 287 is a BL Lac object located 3.5 billion light years away that has produced quasi-periodic optical outbursts going back approximately 120 years, as first apparent on photographic plates from 1891...

 confirmed Einstein's general theory of relativity
.

Books by Mauri Valtonen

• Valtonen, M. & Karttunen, H. (2006). The Three-Body Problem. 251 pages. Cambridge University Press.
• Byrd, G. G., Chernin A. D. & Valtonen M. (2007). Cosmology: Foundations and Frontiers. Moscow: URSS.

External links

• OJ 287 2005-2008 Project (Tuorla Observatory)
• A Supermassive Black Hole Pairing (Centauri Dreams)
• Mauri Valtonen's home page