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No. 40: Jul-Aug 1985

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What is it? a black hole, of course!

Radio-telescope measurements of the compact radio source, churning away in the center of our Galaxy, reveal that it is only 20 AU in diameter at radio wavelengths of l.35 centimeters. This is roughly the size of the solar system inside Saturn's orbit. This tiny radio source is so energetic that there seems no escaping the conclusion that it is a blackhole. No other astronomical object is capable of generating so much energy in so small a volume. Since other galaxies also seem to harbor small, but very powerful radio sources in their centers, astronomers wouldn't be too surprised if all galaxies had black-hole cores. Quasars, in fact, might be galaxies with spectacularly active centers.

Would these unseeable black holes be the notorious "missing mass" in the universe? Not likely. The mass of the purported black hole in our Galaxy is only about several million solar masses-- not even close to what is needed.

(Maddox, John; "Black Hole at the Galactic Centre," Nature, 315:93, 1985.)

Comment. Actually, it would be rather amusing if the problem of the missing mass, which we cannot see, were solved by black holes, which we cannot see either!

Reference. Black holes and other cosmological entities are discussed in our Catalog: Stars, Galaxies, Cosmos. to order the book, visit: here.

From Science Frontiers #40, JUL-AUG 1985. 1985-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987