2007 Aurigids Meteor Outburst
predicted circumstances
Aurigids outburst, predicted details:
When: 2007 September 1 at 04:15 a.m. PDT plus or minus 20 minutes, with a main activity window of 30 minutes to either side of the peak time.
Where: The Pacific Northwest is ideally situated. Too far east or north would put the peak time into daylight, or at least twilight. Too far south or west would lower the radiant altitude in the sky, hiding many meteors. But areas in the western U.S. States and Canadian Provinces down to Mexico and out to Hawaii will be able to see at least some of this rare event.
About meteors: Meteor events, also called "shooting stars", are classified as "sporadic" (unpredicted and no known association with a comet); "showers" (annual, from streams that have diffused in space); "outbursts" (Earth passes through a small or widely-spread stream); or "storms" (raresr events, when Earth passes through a large, concentrated stream and produces more than 1000 meteors per hour).
What is predicted: The Earth will pass through one of the streams from the annual meteor shower named the "Aurigids" after the constellation the meteors appear to come from, Auriga the Charioteer. That constellation contains the bright star Capella, the third-brightest star in the northern skies. The Aurigids previously made unpredicted appearances in 1935, 1986, and 1994. But astronomers have now learned how to predict the origin and motions of these invisible meteor streams through space. The origin is Comet Kiess, which last appeared in 1911. And in 2007, the Earth will again pass directly through one of the streams that escaped from the comet, producing a short-lived but intense outburst of meteors. The duration will be an hour or less. The predicted peak rate is 300 meteors per hour, uncertain by a factor of three. These will mostly be brighter-than-average meteors, easily visible in a clear, dark sky away from city lights.
Observing recommendations: The radiant will be high in the eastern sky when viewed from Washington State. Meteors will travel in all directions, but their paths will all trace back to the constellation Auriga. To see the most meteors, recline on a blanket or in an easy chair so as to get a comfortable overhead view. Meteors will originate from a point high in the eastern sky, but the Moon will be in the southeast, so face away from the Moon or use an obstacle to block direct moonlight from your eyes. Dress for very cool weather at that early morning hour. Avoid or screen off artificial light sources. Conditions are optimal if you can see the faint band of the Milky Way in the northwest despite the moonlight.
For additional information, see http://www.skyandtelescope.com/observing/home/9332696.html or "EOS, Transactions , American Geophysical Union 98:317-318 (2007 Aug. 7).