page_title: Aleksander Wolszczan
section_title: Scientific career
hierarchical_section_title: Aleksander Wolszczan / Scientific career
caption_attribution_description: Čeština: Aleksander Wolszczan, v budově Astronomického centra v Piwnicích u Toruně, Polsko English: Aleksander Wolszczan, Piwnice Observatory (Toruń), Poland Polski: Aleksander Wolszczan, w budynku Centrum Astronomii w Piwnicach koło Torunia
context_page_description: Aleksander Wolszczan is a Polish astronomer. He is the co-discoverer of the first extrasolar planets and pulsar planets.
context_section_description: Wolszczan sat for an M.Sc. in 1969 and a Ph.D. in 1975 at the Nicolaus Copernicus University in Toruń, Poland. Between 1969-73 he worked at the Department of Radioastronomy of the Institute of Astronomy. In 1973, as a senior assistant, he moved to Bonn for training at the Max Planck Institute for Radio Astronomy. From 1979 to 1982 he worked at the Astronomical Center of the Polish Academy of Sciences in Toruń, and in 1982 he moved to the United States to work at Cornell University and Princeton. Later he became an astronomy professor at Pennsylvania State University. From 1994 to 2008, he was also professor at the Nicolaus Copernicus University. He is a member of the Polish Academy of Sciences.
  Working with Dale Frail, Wolszczan carried out astronomical observations from the Arecibo Observatory in Puerto Rico that led them to the discovery of the pulsar PSR B1257+12 in 1990. In 1992 they showed that the pulsar was orbited by two planets, whose masses were initially assessed at 3.4 and 2.8 times Earth's mass. The radii of their orbits are 0.36 and 0.47 AU respectively. This was the first confirmed discovery of planets outside the Solar System (as of 6 October 2017, 3,529 such planets were known). Wolszczan announced his findings in 1992 during the Meeting of the American Astronomical Society in Atlanta. Two years later he published the results of his discovery and was chosen by the journal Nature as the author of one of 15 fundamental discoveries in the field of physics. Despite some initial misgivings by several experts, today his discovery is regarded as fully substantiated. Astronomer Bohdan Paczyński called it "the greatest discovery by a Polish astronomer since Copernicus." In 1998, Astronomy magazine included his discovery among The 25 Greatest Astronomical Findings of All Time. At the Arecibo Observatory, Wolszczan also collaborated with Joseph H. Taylor Jr and conducted research on millisecond pulsars.
  In 2003 Maciej Konacki and Wolszczan determined the orbital inclinations of the two pulsar planets, showing that the actual masses were approximately 3.9 and 4.3 Earth masses respectively.
  In 2007, Wolszczan was also part of a Polish team of astronomers led by Andrzej Niedzielski that found yet another planet outside the Solar System, HD 17092 b, orbiting star HD 17092.
  In 2012, Matthew Route and Wolszczan detected bursts of radio waves emitted from 2MASS J10475385+2124234 using Arecibo Observatory.  This T6.5 brown dwarf has a temperature of 800-900 K, making it the coolest known radio-emitting substellar object.  Its magnetic field is stronger than 1.7 kG.  In 2016, the team discovered the most rapidly rotating brown dwarf, the T6 WISEPC J112254.73+255021.5.  Its rotation period may be as little as 17 minutes.
  Wolszczan is a member of many scientific associations which include: the Polish Academy of Sciences, American Astronomical Society, American Association for the Advancement of Sciences, International Union of Radio Science, International Astronomical Union, and Polish Institute of Arts and Sciences of America.
caption: Aleksander Wolszczan
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