Julio Ángel Fernández

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Dr. Julio Ángel Fernández Alves (born Montevideo, 5 April 1946) is a Uruguayan astronomer and member of the department of astronomy at the Universidad de la República in Montevideo. He is also a member of PEDECIBA, (the program for development of basic sciences in Uruguay).[1] From 2005 to 2010, he was the Dean of the Universidad de la Republica's Faculty of Sciences.[2] The asteroid 5996 Julioangel was named after him.

Kuiper belt[edit]

In 1980, in his paper On the existence of a comet belt beyond Neptune, Fernández proposed that periodic comets arrived too frequently into the inner Solar System to be accounted for solely by having arrived from the Oort cloud, and that a trans-Neptunian belt of comets at around 50 AU would be required to explain them.[3] Subsequent computer models by Martin Duncan, Tom Quinn and Scott Tremaine in Canada supported the view, and led eventually to the discovery of the Kuiper belt.[4] Many astronomers, including David Jewitt, who discovered the belt, believe that Fernández deserves more credit than anyone else, including Gerard Kuiper, for predicting its existence.[5] He has subsequently published many papers on the trans-Neptunian population.[1]

Definition of planet[edit]

In 2006, Fernández was one of a number of dissenters at the IAU's meeting to establish the first definition of "planet." As an alternative to the IAU's draft proposal, which had included Pluto, its moon Charon and Ceres among the planets, Fernández's proposed definition reserved the term "planet" only for those objects in the Solar System which had cleared their neighbourhoods of planetesimals, describing those objects which had not cleared their orbits yet retained a spherical shape as "planetoids."[6] The IAU's final definition incorporated much of Fernández's proposal, though the objects were christened "dwarf planets."[7]


  1. ^ a b Julio Fernandez. "Página personal del Dr. Julio A. Fernández". Universidad de la República. Retrieved 2008-02-08. 
  2. ^ Heber Rizzo Baladán (2006). "Los mundos helados de Julio A. Fernández". Retrieved 2009-11-07. 
  3. ^ JA Fernandez (1980). "On the existence of a comet belt beyond Neptune". Observatorio Astronomico Nacional, Madrid. Retrieved 2007-06-20. 
  4. ^ M. Duncan, T. Quinn, and S. Tremaine (1988). "The origin of short-period comets". The Astrophysical Journal. Retrieved 2007-06-20. 
  5. ^ David Jewitt. "WHY "KUIPER" BELT?". University of Hawaii. Retrieved 2007-06-14. 
  6. ^ Britt, Robert Roy (2006-08-18). "Pluto May Get Demoted After All". Space.com. Retrieved 2006-08-24. 
  7. ^ "IAU 2006 General Assembly: Resolutions 5 and 6". IAU. 24 August 2006. 

External links[edit]