Tom Bolton (astronomer)
{{Short description|American-Canadian astronomer (1943–2021)}}
{{Infobox scientist
| name = Tom Bolton
| birth_name = Charles Thomas Bolton
| image =
| image_size =
| caption =
| birth_date = {{birth date|1943|4|15}}
| birth_place = Tullahoma, Tennessee, U.S.
| death_date = {{circa|February 4, 2021}} (aged 77)
| death_place = Richmond Hill, Ontario, Canada
| fields = Astronomy
| workplaces = David Dunlap Observatory, University of Toronto
| alma_mater = University of Illinois
University of Michigan
| known_for = Evidence for Stellar-mass black holes
| awards = Fellow of the Royal Society of Canada
| footnotes =
}}
Charles Thomas Bolton (April 15, 1943 – {{circa|February 4, 2021}}){{cite news|url=https://www.theglobeandmail.com/canada/article-astronomer-tom-bolton-found-compelling-evidence-of-a-black-holes/|title=Astronomer Tom Bolton found compelling evidence of a black hole's existence|work=The Globe and Mail|date=2021-02-19|access-date=2022-01-31}} was an American-Canadian astronomer who was one of the first in his field to present strong evidence of the existence of a stellar-mass black hole.{{cite web | url = http://astro-canada.ca/_en/a2214.php | title = Charles Thomas Bolton (1943- ) | publisher = Virtual Museum of Canada | accessdate = 2007-07-05 }}{{Cite book|contribution=Tom Bolton, Astronomer: Discoverer of the First Black Hole|title=Canadian Scientists and Inventors: Biographies of People Who Shaped Our World|last=Black|first=Harry|publisher=Pembroke Publishers Limited|year=2008|pages=24–27|isbn=978-1-55138-222-7}}.
Biography
Bolton was born in Camp Forrest, a military base in Tullahoma, Tennessee. He received his bachelor's degree in 1966 from the University of Illinois, followed by a 1968 master's degree and a 1970 doctoral degrees from the University of Michigan.
Bolton then worked as a postdoctoral researcher at the David Dunlap Observatory in Richmond Hill, Ontario, teaching there until 1972. He taught at Scarborough College from 1971 to 1972, and at Erindale College from 1972 to 1973. Thereafter, he was affiliated with the University of Toronto astronomy department, eventually becoming an emeritus professor.[http://www.astro.utoronto.ca/people/faculty/memberinfo_view?userId=bolton Faculty profile] {{webarchive|url=https://archive.today/20120718182748/http://www.astro.utoronto.ca/people/faculty/memberinfo_view?userId=bolton|date=2012-07-18}}, U. of Toronto Astronomy and Astrophysics Dept.
In 1970, Bolton developed the first computer models for stellar spectra that were precise enough to compare with data from real stars.
In 1971, as a post-doctoral fellow and part-time faculty member studying binary systems at the Dunlap Observatory,{{cite web | url = http://www.magazine.utoronto.ca/02autumn/blackhole.asp | title = The proof is out there | first = Kritine | last = Culp | publisher = University of Toronto Magazine | accessdate = 2008-07-06 }}{{cite news | url = http://www.cbc.ca/technology/quirks-blog/2008/04/black_holes_the_canadian_conne.html | title = Black holes: The Canadian connection | work = Quirks and Quarks | publisher = CBC | date = 2008-04-18 | accessdate = 2008-07-05 }} Bolton observed star HDE 226868 wobble as if it were orbiting around an invisible but massive companion emitting powerful X-rays,{{cite journal | last=Bolton | first=C. T. | year=1972 | title=Identification of Cygnus X-1 with HDE 226868 | journal=Nature | volume=235 | issue=5336 | pages=271–273 | doi=10.1038/235271b0 | bibcode=1972Natur.235..271B| s2cid=4222070 }} independently of the work by Louise Webster and Paul Murdin, at the Royal Greenwich Observatory.{{cite journal | last=Webster | first=B. Louise |author2=Murdin, Paul | title=Cygnus X-1—a Spectroscopic Binary with a Heavy Companion? | journal=Nature | year=1972 | volume=235 | issue=5332 | pages=37–38 | doi=10.1038/235037a0 | bibcode=1972Natur.235...37W| s2cid=4195462 }} 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 more 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.{{cite web | last=Rolston | first=Bruce | date=November 10, 1997 | url=http://news.utoronto.ca/bin/bulletin/nov10_97/art4.htm | title=The First Black Hole | publisher=University of Toronto | accessdate=2008-03-11 |archiveurl = https://web.archive.org/web/20080307181205/http://www.news.utoronto.ca/bin/bulletin/nov10_97/art4.htm |archivedate = 2008-03-07}}
{{cite journal | last=Shipman | first=H. L. | title=The implausible history of triple star models for Cygnus X-1 Evidence for a black hole | journal=Astrophysical Letters | year=1975 | volume=16 | issue=1 | pages=9–12 | bibcode=1975ApL....16....9S | doi=10.1016/S0304-8853(99)00384-4}}{{cite journal | last=Gursky | first=H. | year=1971 |author2=Gorenstein, P. |author3=Kerr, F. J. |author4= Grayzeck, E. J. | bibcode=1971ApJ...167L..15G | title=The Estimated Distance to Cygnus X-1 Based on its Low-Energy X-Ray Spectrum | journal=Astrophysical Journal | volume=167 | pages=L15 | doi=10.1086/180751 }}
In 1985, Bolton and Douglas Gies showed that hot, massive "runaway OB stars" (stars that travel at an abnormally high velocity relative to the surrounding interstellar medium), could be accelerated through stellar interactions within star clusters, in addition to being ejected from binary systems after supernova explosions.{{Cite journal|last1=Gies|first1=D. R.|last2=Bolton|first2=C. T.|date=1986|title=The binary frequency and origin of the OB runaway stars|journal=The Astrophysical Journal Supplement Series|language=en|volume=61|pages=419|doi=10.1086/191118|bibcode=1986ApJS...61..419G|issn=0067-0049}}
Bolton was instrumental in passing the first light-pollution regulation Canada, a 1995 bylaw to limit light pollution in the town Richmond Hill, home of the David Dunlap Observatory.{{Cite news|url=https://www.thestar.com/news/2008/03/20/lights_out_for_pollution.html|title=Lights out for pollution {{!}} The Star|work=thestar.com|access-date=2018-10-30|language=en}} He was a fellow of the Royal Society of Canada. Bolton died in February 2021, at his home in Richmond Hill.{{cite magazine |url=https://baas.aas.org/pub/2021i0316/release/1 |title=Charles Thomas Bolton (1943–2021) |magazine=Bulletin of the American Astronomical Society |author=Alexander W. Fullerton, Douglas R. Gies, Ian K. Shelton, and Steven N. Shore |date=April 13, 2021 |volume=53 |issue=2 |accessdate=January 9, 2022}}
References
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Category:20th-century American astronomers
Category:21st-century Canadian astronomers
Category:Academic staff of the University of Toronto Mississauga
Category:Academic staff of the University of Toronto Scarborough
Category:Fellows of the Royal Society of Canada
Category:University of Illinois alumni
Category:University of Michigan alumni