Nov 17/18 Meteors and the Leonids over Asia
November 18, 2009
As predicted, the Earth’s passage through the 1466 and 1533 dust trails of Comet Tempel-Tuttle resulted in enhanced Leonid activity. Due to the time when the activity occurred, it was only visible to observers in Asia. Visual reports to the International Meteor Organization (IMO) suggest a peak around 20-21 hours UT with rates 80-140 per hour. This matches the lower values predicted by computer models. Though early predictions called for 500-1000 meteors per hour, recent revisions brought the predicted rates down to 100-200 per hour. The plot below from the IMO shows rate of activity for the past few days (you should be able to click on the plot to expand it).
Even though rates of 100+ meteors per hour are great and real fun to watch, they are not high enough to be considered a meteor storm. In fact they are comparable to the peak activity ofthe annual Perseid and Geminid showers. So if you missed the Leonids at their best, don’t worry, the Geminids will be just as good in a few weeks (Dec 13/14).
Last night’s video data shows activity levels that were a bit lower than the night before. As the IMO plot above shows, the times when the Leonids were observable from my site (~8 to 13 hours UT) bracket the peak activity. For the last 2 nights, Leonid activity over the US has been moderate with ZHRs of 20-30 per hour. Rates should gradually decrease as we move away from the Leonid dust trails.
Bob’ notes for the night of Nov 17/18 : “Last night saw fog rushing in at dusk only to retreat shortly thereafter. This went on all night long therefore rates are slightly down compared to yesterday. The Leonids were down significantly from the previous night. I would expect a slight improvement in Leonid rates on the 19th. After a good showing last night. the Andromedids failed to appear tonight.”
Obs Date(UT)Time TOT SPO NTA STA LEO AMO NOO AND OER TUS Nov-18 11h12m 81 22 3 1 40 5 2 1 1 SDG Nov-18 11h40m 62 28 6 2 20 3 2 0 1
TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – Total amount of time each camera looked for meteors
TOT – Total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
LEO – Leonids
AMO – Alpha Monocerotids
NOO – November Orionids
AND – Andromedids
OER – Omicron Eridanids