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Black Holes - http://imagine.gsfc.nasa.gov/docs/science/know_l2/black_holes.html
Black hole page from NASA's "Imagine the universe!" site; includes a section on observational aspects - "If We Can't See Them, How Do We Know They're There?" |
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Radio Astronomers Lift 'Fog' on Milky Way's Dark Heart - http://www.nrao.edu/pr/2004/sagastar/
Press release by the National Radio Astronomy Observatory about observations of the immediate neighborhood of our galaxy's central supermassive black hole. |
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Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way - http://arxiv.org/abs/astro-ph/0210426
Article by R. Schodel and colleagues (Max Planck Institute for Extraterrestrial Physics) about the best evidence to date for the existence of a supermassive black hole in the center of our own galaxy - the way it influences the orbits of nearby stars. |
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Do Black Holes Exist? - http://pgostrov.googlepages.com/e3.html
Brief text by Pablo G. Ostrov about the evidence for the existence of black holes, aimed at a general audience. |
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XMM: Black Holes and Quasars - http://www.sr.bham.ac.uk/xmm/blackholes.html
Educational pages on the website of the space-borne X-ray telescope XMM, hosted by the University of Birmingham. Information about black holes and other astronomical sources of X-rays. |