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Paul Kalas (born August 13, 1967) is an astronomer known for his discoveries of circumstellar debris disks (i.e. debris disks around stars) (ref [5]).


Kalas was born in New York to George and Maria Kavallinis, who immigrated to the United States from Heraklion, Crete. Kalas attended Detroit Country Day School in Michigan, and studied Astronomy and Physics at the University of Michigan, Ann Arbor. He earned a Ph.D in Astronomy in 1996 from the University of Hawaii, under the direction of astronomer David Jewitt. Kalas worked as a postdoctoral scientist at the Max Planck Institute for Astronomy in Heidelberg, Germany, the Space Telescope Science Institute, and the University of California, Berkeley. He became an Adjunct Professor of Astronomy at the University of California at Berkeley in 2006 (ref [5]).

Kalas lives with his wife Aspasia Gika and daughters Maria-Nikoleta and Natalia in Berkeley, California (ref [5]).


Kalas discovered several circumstellar disks using a coronagraph on the Hubble Space Telescope and at the University of Hawaii 2.2m telescope at Mauna Kea, Hawaii. In 1995 he discovered various forms of asymmetric structure in optical images of the Beta Pictoris disk (ref [4]). He was the lead scientist for the first optical images of debris disks surrounding the nearby red dwarf AU Microscopii and the bright star Fomalhaut (ref [2], [3]). Kalas' Hubble Space Telescope image of Fomalhaut revealed a narrow belt of dusty material analogous to the solar system's Kuiper Belt. However, Kalas also found that Fomalhaut's belt is narrow and geometrically offset from the star by 15 astronomical units. These features are considered strong evidence for an extrasolar planet orbiting Fomalhaut that gravitationally sculpts the morphology of the belt.

Circumstellar disks discovered: 5

AU Microscopii October 14, 2003 Ref. [3]
Fomalhaut May 17, 2004 Ref. [2]
HD 15115 July 17, 2006 Ref. [6]
HD 53143 September 11, 2004 Ref. [1]
HD 139664 October 14, 2004 Ref. [1]


[1] Kalas, P.; Graham, J.R., Clampin, M.C. & Fitzgerald, M. (2006). "First scattered light images of debris disks around HD 53143 and HD 139664". The Astrophysical Journal 635: L57-L60. doi:10.1086/500305. 

[2] Kalas, P.; Graham, J.R. & Clampin, M. (2005). "A planetary system as the origin of structure in Fomalhaut's dust belt". Nature 435 (7045): 1067-1070. doi:10.1038/nature03601. 

[3] Kalas, P.; Liu, M.C. & Matthews, B.C. (2004). "Discovery of a large dust disk around the nearby star AU Microscopii". Science 303 (5666): 1990-1992. doi:10.1126/science.1093420. 

[4] Kalas, P.; Jewitt, D. (1995). "Asymmetries in the Beta Pictoris dust disk". The Astrophysical Journal 110: 794-804. doi:10.1086/117565. 

[5] Kalas' homepage

[6] Kalas, P.; Fitzgerald, M. & Graham, J.R. (2007). "Discovery of extreme asymmetry in the debris disk surrounding HD 15115". The Astrophysical Journal 661: L85-L88. doi:10.1086/518652. 


* The Circumstellar Disk Learning Site

* Kalas' homepage

* Sky & Telescope Article on Fomalhaut discovery

* article on AU Microscopii discovery

* New Scientist article on HD 53143 and HD 139664 discoveries


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