4 results found.
... Science Frontiers ONLINE No. 127: Jan-Feb 2000 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Black Auroras July 23/24, 1998. Gulf of St, Lawrence. Aboard the m.v . Appleby , Port Cartier to Immingham. "The aurora borealis was sighted at 0330 UTC. There was a band measuring 35 long in azimuth, with deepblue almost black vertical bands lying between the altitudes of 15 and 25 . The colour changed to brilliant blue at 0335, lasting for about 15 minutes before cloud began to obscure it." What were the "almost black" vertical bands embedded in the main band? Aurora expert R. Livesey replied as follows. "There is a phenomenon called the 'black aurora' which consists of small regions of very low luminosity embedded in brighter auroral light; the 'black' rays reported from the Appleby could have been a phenomenon of this type." (Wilson, J.L .; "Aurora Borealis," Marine Observer, 69:112, 1999.) Black auroras may actually be more than just the contrast effect suggested by Livesey. Low-light TV systems detect clockwise vorticity in the black bands, and the bands seem to be associated with upward electron beams. In other words, black auroras are apparently a distinct phenomeon in their own right and not just nonluminous parts of the visible aurora. (Stenbaek-Nielsen, H.C ., et al; "Why Do Auroras Look the Way They Do?" Eos, 80:193 ...
Terms matched: 1 - Score: 29 - 15 May 2017 - URL: /sf127/sf127p00.htm
... Science Frontiers ONLINE No. 121: Jan-Feb 1999 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Tunguska Afterglow June 30, July 1-3 , 1908. England. We quote from a London cable to the New York Times. "Several nights through the week were marked by strange atmospheric effects which Dr. Norman Lockyer of the South Kensington Solar Physics Laboratory believes to be a display of the aurora borealis, though personally I have not observed any colored streamers. "Following sunsets of exceptional beauty and twilight effects remarkable even in England, the northern sky at midnight became light blue, as if the dawn were breaking, and the clouds were touched with pink, in so marked a fashion that police headquarters was rung up by several people, who believed a big fire was raging in the north of London." (Anonymous; "Like Dawn at Midnight," New York Times, July 5, 1908. Cr. M. Piechota) Comment. Actually, all of northern Europe saw a succession of very bright nights beginning June 30, 1908. It was even possible to take photographs at midnight. The cause was not the aurora borealis but rather the Tunguska Event (Siberian Meteor) of June 30, 1908. Of course, Western Europe did not know what had happened in Siberia for years. Terrestrial dust from the Tunguska Event that was blasted into the upper atmosphere or perhaps particulate matter accompanying the impacting object (probably a comet) was apparently the cause of the nightime airglow. From Science Frontiers #121 ...
Terms matched: 1 - Score: 29 - 15 May 2017 - URL: /sf121/sf121p12.htm
... Science Frontiers ONLINE No. 49: Jan-Feb 1987 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Enormous Stellar Shell Raises Theoretical Questions "Stars tend to lose material to the space that surrounds them. Some of this loss is gradual and continuous -- the so-called stellar winds. Some is abrupt -- the sudden blowing off of a surface layer that then forms a shell around the star. A group of astronomers now reports in the Nov. 15 Astrophysical Journal the discovery of an especially large, cool shell around the star R Coronae Borealis. How this shell was formed and what makes it glow are both mysteries for which current theory does not seem to have answers." The newly discovered shell is 26 light-years across, roughly 20 times larger than previously discovered shells. If our sun were in the center, the shell would encompass the nearest 50 stars! The usual stellar shells glow as they absorb and reemit radiation from their parent stars, but the R Coronae Borealis shell, given its distance from its star, cannot be explained in this way. (Thomsen, D.E .; "Enormous Stellar Shell Raises Theoretical Questions," Science News, 130:333, 1986.) From Science Frontiers #49, JAN-FEB 1987 . 1987-2000 William R. Corliss ...
Terms matched: 1 - Score: 29 - 15 May 2017 - URL: /sf049/sf049p03.htm
... as the famous February 9, 1913, bolide procession that amazed inhabitants of eastern North America. Unhappily, we only have room to quote one paragraph from a 10-page report. "General outline of the phenomenon. At night, early on the 20th of September of 1977, over a vast area in the northwest of the European part of the USSR, unusual light phenomena in the atmosphere were observed, namely formation and motion of bright, luminous bodies surrounded by extended shells and emitting light rays or jets of quaint shapes. The shells transformed and diffused within 10 to 15 minutes. Besides, a more longlived, stable glow was observed, mostly in the northeastern part of the sky. These phenomena took place during disturbances of the geomagnetic field and the upper atmosphere. Somewhere, aurora borealis was seen." (Gindilis, L.M ., and Kolpakov, Yu.K .; "The Petrozavodsk Phenomenon," RIAP Bulletin, 2:3 , April-September 1995. RIAP = Research Institute of Anomalous Phenomena, P.O . Box 4684, 310022 Kharkov-22, UKRAINE) References. The 1913 meteor procession is described in AYO7 in our catalog: The Sun and Solar System Debris. Also see: SF#79. Details on our catalog here . The Petrozavod phenomenon as seen near Lehta. From Science Frontiers #104, MAR-APR 1996 . 1996-2000 William R. Corliss ...
Terms matched: 1 - Score: 13 - 15 May 2017 - URL: /sf104/sf104p07.htm