18 November 1999
The Leonid Shower
By Lorenzo Comolli

Here are some photos obtained in the morning of 18 November 1999. The first data indicate a HR (Hourly Rate) of about 1500 meteor/hour.

I've gone to Mt. S.Martino (Italian Alps, 1087m) even if there was a lot of snow! I and Alberto Brunati see a lot of meteors and also three bolides, two of m=-15 and one of m=-10. I captured on film the first of these, and also the trail that was visible for about 20 minutes!


Click on the image for the bigger version

Here are the details of the bolide and the trail.
 

Zoom -> 
Top-left: the bolide of m=-15 in the costellation of Leo. 50mm f/1.8, 4 minutes exposure in PJ-400. Location: Mt. S.Martino.

Top-right: zoom of the last image.

Left: the wonderful trail of the bolide.

Bottom: composition of 5 images that show all the meteors of 20 minutes.There are visible 17 meteors.
 

For all: click on the image for the bigger version
 
The fireball of 1.43 UT is visible also in a corner of this big field image obtained with a 16mm f/2.8 objective, PJ-400 film, 8 minutes exposure.
A lot of constellations are visible: Orion, Taurus, Perseus, Canis Maior and Minor, Gemini, Auriga...
Jupiter and Saturn are visible at right.
The morning twlight: in the center there is Venus. Note the snow on the parking on San Martino.

THE OBSERVATIONS
Here is some graphs obtained from data acquired in that night. The value refers to the number of meteors seen by a single observer (myself). Note the peak at about 2 UT. (sorry for internal labels in Italian, but the the significate is obvious)
 
Graph of the HR (hourly rate).
Istograms of 5 minutes each of the HR. The different colours of some colums indicate that the values are interpolation beetwen two observations.

Istograms of 5 minutes each of the ZHR (zenithal hourly rate). The different colours of some colums indicate that the values are interpolation beetwen two observations.
(Note: in the calulation of the ZHR I used a population index (r) of 2).
Istograms of the distibution in magnitude of the Leonids. Note the absence of a great number of bolides. I was obtained from data of about 100 meteors.

For all comment or critics, write to: comolli@libero.it

HTML Editing and Publishing by Lorenzo Comolli. Email me at comolli@libero.it.
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