In yesterday’s “The November Meteor Storms – Part II – The Leonids” posting, it was mentioned that there were a few chances for elevated activity last night for Europe and Asia. Mikhail Maslov predicted a high rate of Leonids for an hour or so on either side of 00h 22m UT on November 17. Jérémie Vaubaillon also predicted elevated rates of Leonids centered at 01h 32m UT on November 17. According to Vaubaillon, the high rates would be due to the Earth crossing a trail of dust released by Comet Tempel-Tuttle in 1466.
According to the International Meteor Organization‘s Leonids 2008 Live webpage, a nice outburst of Leonids was observed at ~02h 00m UT on November 17. Based on the Leonids Live page and posts to the Meteorobs list at Yahoo Groups, observers in Europe and Israel witnessed the outburst. Rates may have reached as high as ZHR=~130.
By the time the Leonids were visible from the United States, the outburst was over. The 23 Leonids seen by my Tucson-based camera show that no outburst was visible over Tucson. Bob’s tally of 30 Leonids over San Diego also confirms this. Comparing video rates with naked eye observeing rates is tricky. Last month, when my camera detected roughly ~23 Orionids in a night, the visual observers were measuring ZHRs (zenithal hourly rate) of 10-20. So, with a bit of hand waving, the Leonids were falling at a ZHR of 10-20 over the western US last night. This is the expected rate for the Leonids when no elevated activity is seen. As you will see in Bob’s comments, his experience is that the Leonids will continue to strengthen till the morning of the 19th. So maybe there is more to come.
From Bob Lunsford’s notes: “The weather continues to cooperate in San Diego. I had the camera on from dusk to dawn and recorded 87 meteors. The first Leonid was recorded at 12:30 am PST and 29 more were caught the remainder of the night. That is an average of roughly 6 Leonids per hour. While Carl has mentioned the possibility of enhance rates may seen from the eastern hemisphere on the 17th, my personal data show that the strongest Leonid rates have been occurring on the morning of November 19th. We will have to see what actually happens.”
Jérémie Vaubaillon predicts the possibility of another period of elevated Leonid activity at 21:38 UT on November 18 though rates will may not be as high as those seen last night over Europe. This “outburst” will be observable over Asia.
Below are 2 movies from Tucson. The 1st shows the brightest Leonid (or meteor of any kind) observed by my Tucson-based camera last night. This doesn’t mean that there weren’t even brighter meteors observable over Tucson. My camera only covers a small fraction of the sky so I do miss a lot of meteors.
The 2nd movie shows 47 of the meteors detected by my Tucson-based camera. The camera is fixed so you can easily see the stars and the Moon moving from East to West through the field. The big white blob moving along the bottom of the frame is the Moon.
Obs Date (UT) TotTime TOT SPO NTA STA LEO AMO TUS 2008-11-17 11h 33m 48 22 0 1 23 2 SDG 2008-11-17 11h 27m 87 45 6 5 30 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 – Northern Taurids
STA – Southern Taurids
LEO – Leonids
AMO – Alpha Monocerotids