Tom Bolton (astronomer)

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Charles Thomas Bolton (born 1943) is an American astronomer who was one of the first astronomers to present strong evidence of the existence of a stellar-mass black hole.[1][2]

Bolton received his Bachelor’s in 1966 from the University of Illinois, followed by a 1968 Master’s and a 1970 doctoral degrees from the University of Michigan.[1] Bolton then worked as a postdoctoral researcher at the David Dunlap Observatory, teaching there until 1972.[1] He taught at Scarborough College from 1971 to 1972, and at Erindale College from 1972 to 1973, but since 1973, has been affiliated with the University of Toronto astronomy department,[1] where he is now an emeritus professor.[3]

In 1971, as a post-doctoral fellow and part-time faculty member studying binary systems at the Dunlap Observatory,[4][5] Bolton observed star HDE 226868 wobble as if it were orbiting around an invisible but massive companion emitting powerful X-rays,[1][6] independently of the work by Louise Webster and Paul Murdin, at the Royal Greenwich Observatory.[7] Further analysis gave an estimate about the amount of mass needed for the gravitational pull, which proved to be too much for a neutron star. After further observations confirmed the results, by 1973, the astronomical community generally recognized black hole Cygnus X-1, lying in the plane of the Milky Way galaxy at a galactic latitude of about 3 degrees.[1][8][9][10]

Bolton is a fellow of the Royal Society of Canada.[1]


  1. ^ a b c d e f g "Charles Thomas Bolton (1943- )". Virtual Museum of Canada. Retrieved 2007-07-05. 
  2. ^ Black, Harry (2008). "Tom Bolton, Astronomer: Discoverer of the First Black Hole". Canadian Scientists and Inventors: Biographies of People Who Shaped Our World. Pembroke Publishers Limited. pp. 24–27. ISBN 978-1-55138-222-7. .
  3. ^ Faculty profile, U. of Toronto Astronomy and Astrophysics Dept.
  4. ^ Culp, Kritine. "The proof is out there". University of Toronto Magazine. Retrieved 2008-07-06. 
  5. ^ "Black holes: The Canadian connection". Quirks and Quarks. CBC. 2008-04-18. Retrieved 2008-07-05. 
  6. ^ Bolton, C. T. (1972). "Identification of Cygnus X-1 with HDE 226868". Nature. 235 (5336): 271–273. Bibcode:1972Natur.235..271B. doi:10.1038/235271b0. Retrieved 2008-03-10. 
  7. ^ Webster, B. Louise; Murdin, Paul (1972). "Cygnus X-1—a Spectroscopic Binary with a Heavy Companion?". Nature. 235 (5332): 37–38. Bibcode:1972Natur.235...37W. doi:10.1038/235037a0. Retrieved 2008-03-10. 
  8. ^ Rolston, Bruce (November 10, 1997). "The First Black Hole". University of Toronto. Archived from the original on 2008-03-07. Retrieved 2008-03-11. 
  9. ^ Shipman, H. L. (1975). "The implausible history of triple star models for Cygnus X-1 Evidence for a black hole". Astrophysical Letters. 16 (1): 9–12. Bibcode:1975ApL....16....9S. doi:10.1016/S0304-8853(99)00384-4. 
  10. ^ Gursky, H.; Gorenstein, P.; Kerr, F. J.; Grayzeck, E. J. (1971). "The Estimated Distance to Cygnus X-1 Based on its Low-Energy X-Ray Spectrum". Astrophysical Journal. 167: L15. Bibcode:1971ApJ...167L..15G. doi:10.1086/180751.