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| Anne McConnell asks: | |
A friend is writing a paper about Indian Rock Art, and needs some information on any celestial events (comets, meteors, meteor showers, supernovas [other than the Crab Nebula of 1054 A.D.], eclipses) etc. between 1000 A.D.—1300 A.D. Where would I look to find them?" |
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Dr. Bruce Weaver, Director of MIRA, responds: |
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Hmmmm...not as easy as one might think. All such things are listed separately (at best). The eclipses are in the Canon of Eclipses (should be in the UNLV library). Each one comes with a diagram showing the umbra and penumbra paths. There are several eclipses a year since there are two or three eclipse seasons and you have to get at least one solar eclipse in each of them. Lunar eclipses are slightly rarer but are visible over large parts of the globe. There was probably about a 50% chance that at least one full solar eclipse visible from some given spot in a 300 year period; lots of partial solar eclipses (which are easy to miss if they are not close to full eclipses) and a total lunar eclipse every few years. Supernovae are really rare....one in 1006 and one in 1181. The positions of these are well known from the remnants but I don’t know much about the dating. There is a book by Stephenson (Clark and Stephenson, 1977 The Historical Supernaovae. New York:Pergamon Press) on historical supernovae, real and suspected. Meteor showers may have been visible in the usual times... that is probably a much more complicated issue (inner solar system comet capture times, perturbations, etc.) and that goes for comets, too although the Europeans did notice them so there are some records...the best source here is the Chinese (try Ho, Ping-Yu 1962 Ancient and mediaeval observations of comets and novae in Chinese sources, Vistas in Astonomy v.5, p.127). The Chinese recorded meteor showers, too see Tian-shan, Zhuang 1997, Ancient Chinese records of meteor showers, Chinese Astronomy and Astrophysics v.1, p197 [translated from Acta Astron Sinica v.14, p.37, 1966, if you can’t read Chinese]. You have to be a little careful about the short-lived meteor showers (especially notable meteor storms, if any) as they may have been visible for only a short range in longitude. The problem with trying to date regular meteor showers (see any text in astronomy for the current list or see Royal Canadian Astronomical Society handbook) is that they are annual and there are many a year. There is nothing really unique about them unless you get a big clump and those are very localized in longitude. I would think that meteor showers would be VERY tricky to be convincingly unique about. |
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