(meteorobs) Re^2:2012 Draconids

Mikiya Sato mail at kaicho.net
Thu Jan 27 06:26:24 EST 2005


Hello all,

I am Mikiya Sato.

>Now I've computed the circumstances. Unfortunately, the hole in 1959
>trail tells that the most probable is virtual absence of activity. But
>I think there is sence to check 2006 year - younger trails could make
>some intersections.
>
>
>Trail rd-re.  ej. Vel.  fM     sol.long  max. Time   ZHR ex.
>       AU       m/s              deg        UT
>1959 +0,00121  38,7    0,051*  195,624  08.10.12 16:41  0**
>* - very low for Draconids
>** - computed as if it was 55P, not 21P.

I also calculated in 2012. And I had a similar result about 
the trail of 1959 and a interesting result about trail of 1966.
My results are as follows;

In 2012:
Trail   DateTime(UT)  SolLong   dR(AU)  D.sp.  fM      Comment
1959    Oct.08 16:39  195.624  +0.0012  +38.5  0.0033  FM is very small.
1966-1  Oct.08 16:47  195.630  +0.0042  +43.1  0.25    Distance is far.
1966-2  Oct.08 17:27  195.657  +0.0004  +51.4  ****    *1

A fM value of 1959 is very small because of perturbation by the Earth
 in 1992. (My value is smaller than the value by Mikhail Maslov.)

The main trail of 1966(1966-1) is far from the Earth orbit,
 about 0.004[AU]. But a part of trail of 1966(1966-2) is very near.
This part has bent because of perturbation by the Earth in 1972 and 1992.
It seems to encounter the earth in the curved top of trail. 
This is very interesting.

And, I show the results in 1999, referring.
In 1999:

In 1999:
Trail   DateTime(UT)  SolLong   dR(AU)  D.sp.  fM      Comment
1959    Oct.09 10:50  195.714  -0.0026  +60.0  0.20    *2
1966    Oct.09 11:59  195.761  -0.0014  +69.4  0.26    *2

In Japan, the actual peak in 1999 was observed around 11:00(UT) on 
October 9, the HR was about 20 to 30. (*2)
(http://kaicho.pobox.ne.jp/tenshow/meteor/21p/1998e.htm)
Discharge speed were very large (about 60 and 69 [m/s]), 
but I think that this peak was brought by these trails.
(Perihelion distance of these two revolutions, was nearer than 
others.)
So, small or middle peak may be observed in 2012 however discharge 
speed of trail in 2012 is so large.

Best wishes,
Mikiya Sato


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