Wednesday, May 25, 2005

Mark Your Calendars

Adam, this goes especially to you. There is an upcoming meteor shower the weekend of Jeff and Angela's wedding. New England has great skies for such events, especially in the mountains...with the bears. Consider yourself forewarned...

Here is some information taken from skytour.com.

PERSEIDS (maximum August 12, 17h UT [10am PDT; 1pm EDT])
(radiant drift map from IMO)

Moon: First Quarter (minor interference)

Best viewing windows: Thursday evening into Friday morning, August 11/12, from 11pm until morning twilight gets too bright (4:30am or so). The best hours will be the morning ones. As a second option, Friday evening into Saturday morning, August 12/13, from 11pm until 4:30am. Rates may be fairly steady throughout the night.

Recommended for: Just about anyone in the northern temperate latitudes (but a dark-sky site helps a lot)!

The Perseids are definitely the most promising and accessible of this year's meteor showers. The shower has a very long duration, from about July 15 through August 25. Only on a few mornings around the August 12 peak does the shower become really prolific, however. From latitude 40 degrees N, the radiant is above the horizon as the sky starts to get dark. Rates are pretty low then, and this year the First Quarter Moon will be a bit of a deterrent to early observing. The Moon will set before midnight, however, and the Perseids should rule the rest of the night.

West Coast USA observers in particular should try to hit the Friday morning hours of August 12; expect 40-80 Perseids/hour from a truly dark site before morning twilight begins. The best place to observe the peak should actually be eastern Asia. East Coast observers may see rates in the lower part of that range. Friday night into Saturday morning should be productive as well, with peak rates over 40 Perseids/hour from dark sites and the East Coast favored at least slightly.

While these are the absolute best times to view the Perseids, the adjacent mornings (Thursday and Sunday) will also provide good rates (probably exceeding 20 Perseids/hour). View during the last couple of hours before morning twilight for best results. Die-hard observers can follow the stream's off-peak dates throughout early and mid-August without moonlight interference.

Perseids are fast meteors and tend to be fairly bright on average. An occasional fireball is seen, but these seem to depend on the luck of the draw. Perseids are by no means the only meteors visible; in the morning hours, sporadics and several minor showers combine to add ~10-15 meteors to the total. All of this assumes a dark site with the summer Milky Way blazing away. If you've got light pollution problems, both your Perseid and non-Perseid rates are going to be much, much lower. So, get out to a rural or remote site where you can enjoy the Perseids!

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