Wednesday, August 29, 2007

There may be another meteor shower heading our way in the early hours of Saturday, Sept. 1st. I say "maybe" because the Aurigid meteor shower, also known as the alpha-Aurigids, is not one of the regular annual meteor showers produced generally by "short period" comets. The parent body of this "perhaps" shower is a long period comet called Comet Kiess after the astronomer who discovered it in 1911. There is some dispute about the orbital period of this comet. NASA says that the appearance prior to 1911 was in 83 BC (plus or minus "a few centuries"). Others say that the previous appearance of Comet Keiss was in 4 BC plus or minus 40 years. This later reference is to the 'Aurigid Meteor Shower Observing Campaign' that Molly briefly mentioned in a post titled 'The Perseids Are Almost Here' on August 11th. More on this later. The Aurigids are a rare event because the dust trail from long period comets is extremely narrow and it is usually pulled away from the Earth's orbit. Only on occasion does the orbit intersect the dust trail. Jenniskens and Lyytinen have predicted that this year will produce an Aurigid meteor shower that may even eclipse the Perseids earlier this month in intensity.
Molly has seen quite a few people dropping by her blog trying to find out the time of this event and the possibility of viewing it. Will you be able to see it ? Throughout most of North America and all of South America the answer is unfortunately NO. If the predictions of Jenniskens and Lyytinen are right the meteor shower will have a duration of about 1 and 1/2 hour centred on about 4:33 AM Pacific Daylight Time. This is 11:33 AM in GMT. In most of Asia, Europe, Africa and most of the Americas the Sun will be up at the predicted time. If you want to find what time 11:33 GMT translates into in your time zone refer to the trusty old Time And Date website. This will also give you times for such events as sunrise,sunset, moonrise and moonset. The map pictured above gives a visual of the advance of dawn across North America at the predicted time of the Aurigids. Sunrise here in Winnipeg in the Central Daylight Time zone will occur 6:43 AM, just 10 minutes after the predicted peak time of the shower. Most meteors would be obscured by the gathering light of dawn, though it is theoretically possible that you might catch a few if you began observing at say 5:48 AM. For points east it simply won't happen. The best locations for viewing the Aurigids, if they occur, would be on the Pacific coast, in the Pacific Daylight Time zone. People in the southern hemisphere will be unable to view the event because the constellation will be above the northern horizon.
As mentioned above the Aurigids are quite a rare event. In previous appearances of this shower over Europe (1935, 1986,1994) poor viewing conditions and the poor timing of the shower meant that few people were able to observe it. It is estimated that there are only three people alive today who have ever seen this event. If you are lucky enough to see it you will be in a rather select group.
More on the Aurigids later on molly's Blog. Stay tuned.

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