No. 50: Mar-Apr 1987
Several brilliant bluish arcs, some 300,000 light years long, were unexpectedly discovered during a survey of galactic clusters. R. Lynds, of Kitt Peak National Observatory, estimates that the arcs are as luminous as 100 billion suns. The nice circularity of the arcs is perplexing; and it is stated that nothing like them has been reported before. The arcs might be incandescent gas, but many astronomers opt instead for swaths of bright young stars. Spectroscopic tests will decide this point.
It has been difficult to conceive of an origin for the arcs. Are they blast waves or the results of tidal action between galaxies? No one knows, for all suggestions seem flawed. Something out there not only manipulates stupendous amounts of mass and energy but also does it with a draftsman's compass.
(Anderson, Ian; "Astronomers Spot the Biggest Objects in the Universe," New Scientist, p. 23, January 15, 1987.)
Comment. In the interest of accuracy, it should be noted that some superclusters of galaxies are larger than the arcs. Also, some similar phenomena are described in our Catalog volume Stars, Galaxies, Cosmos, viz., the stacked, interleaved arcs of stars around elliptical galaxies (AWO5) and ring galaxies without significant nuclei (AWO6). To order the catalog volume just mentioned, visit: here.
|A luminous arc located near the galaxy cluster 2242-02. (NOAO).|