SJAA

Ephemeris

Showtime For Meteors, Part 1

David North


August is the Perseids, the most popular shower of the year due to high rates and fair weather.

Any meteor seen during August stands a good chance of being a Perseid. Most activity is on August 11-13.

Since 1991, a second peak began with zenithal hourly rates over 100. This new peak occurs prior to the traditional peak. For 1999, the first peak is expected around 4 pm Aug 12/13 (not much good for us) and the traditional peak around 10 that night... which is not a favorable time for us, though we should see good activity between then and 4 a.m.

Rates at max may average 50 - 75/hour, and1999's activity will occur two days after a New Moon.

The brighter members of this shower are often colorful and produce long lasting trains.

The Perseids are associated with Comet P/Swift-Tuttle that visited the inner solar system in late 1992.

Just as the last of the Perseid meteors are seen, the Alpha Aurigids become active.

Rates are usually low for this shower except for a period of about one hour on the morning of Aug. 31/Sep 1.

If you are situated in dark morning skies when this sharp maximum occurs, you may see up to 50 shower members radiating from the Pentagon of Auriga.

This year a Last Quarter moon will be rising near midnight and thus provide moderate moonlit skies as the radiant rises. 1999 Peak should occur at midnight, giving us an opportunity to witness increased activity..?

Shower members seen during this peak of activity are often bright and leave long lasting trains. Notable displays were seen in 1935, 1986, and 1994.


David North; last updated: October 04, 2007 Prev Next