Leonids 18th November

Hi,

Yep its that time of year again. Maximum is predicted for 2h30m UT . The last quarter moon will be in the sky, but at least it better than the full moon we had for the Persieds in August!

This form the IMO website:
"Following the series of strongly enhanced to storm level returns of the Leonids since 1998, associated with the 1998 perihelion passage of the shower's parent comet 55P/Tempel-Tuttle, 2003 may well see falling rates as the shower begins its decline to more "normal" levels of activity. Certainly, no very strongly enhanced activity is predicted, although as meteor enthusiasts know well, surprises can occur from even the best-known showers on occasion! Observers should be alert to covering whatever the shower produces, as following the post-storm phases after this best-ever observed series of storm returns is as vital to our understanding of the stream as seeing the storms themselves.

The Leonid radiant rises usefully only around local midnight (or indeed afterwards south of the equator), not good news, as the last quarter Moon in Leo rises around the same time this year on November 17-18. Observers should persevere however, facing away from the Moon where possible. If the peak occurs at the nodal crossing time (above), it will favor sites across Europe, Africa and the Near East especially, but other peak times cannot be excluded, and observers should be watching for as much of November 16-17 to 19-20 as conditions will allow, in case something unexpected happens. All observing techniques can be usefully employed. "

Cheers,
~Al

here's some more recent info on the Leonids from Daniel Fischer's Cosmic Mirror website.

John F.
SDAS


Leonids 2003 promise 10(!) days of - weak - outbursts

The great storms are over but the Leonids of 2003 are still promising some excitement - though most likely only for the 'experts' and not the public at large. There will be, in all likelyhood, no outbursts with more than 100 or 200 meteors per hour (compared to the storms of 1999, 2001 and 2002 with peaks at 2000 to 5000 per hour), but then again there could be up to seven different peaks, spread out over an unprecendented time interval of ten days, starting on the morning (UTC) of November 13. The main activity, though, can be expected on the morning of November 19, when some even expect a decent display of bright meteors. Here are the predictions by four groups of theorists, all pretty successful in the past few years:

(the table didn't reproduce well so click on this link for the original article) www.astro.uni-bonn.de/~dfischer/mirror/264.html


The first column has the date and up to three UTC times for the respective peak, the second one shows in which year the respective dust trail was produced, and the third carries the expected maximum Zenithal Hourly Rate, again several values. The predictions are by Vaubaillon & Colas, Lyytinen und Asher & McNaught, respectively, and a "-" means that no forecast was made for that particular trail. "The Filament" predictions is by Jenniskens and refers to a resonance in which old (and thus big) meteoroids could be captured: If so, a very broad peak, lasting for almost a day, of fireball activity would be possible, but with a ZHR of 50 at best. Except for Nov. 13 the lunar phase will be fine - and all observations, even negative ones, would help to improve the models even more.