(meteorobs) Encounter of Dust Trail of 15P/Finlay

[Mikiya Sato]

Dear all,

I am Mikiya.

Outbursts of comet 15P/Finlay were observed at the end of last year and
at the beginning of this year. 
So, I tried to calculate the dust trail which was formed from the dust 
ejected at this perihelion in 2014.
As a result, I found that a dust trail from 2014 will encounter the earth 
in 2021 as shown below. 

Peak Time : 2021 Oct.07 01:10 (UT) (LS. : 193.699 deg.)
Delta-R : +0.000037au (5500km!!)
Ejection velocity : +67.35 m/s
fM : 1.1 (1-revolution trail)
RP : Alp. 255.68 deg. Del. -48.35 deg.
Vg : 10.74 km/s

The distance between the earth and the dust trail is very small, 
it is only 5500km.

However, the ejection velocity in the part of this dust trail 
should be 67m/s, which is so large. In case of such a high ejection
velocity, a meteor shower does not appear or the magnitude of meteors
should be very faint if it appears. 
The present outburst of the parent body 15P/Finlay seems to be so large 
that small meteoroids may be released at such a high velocity. Anyway,
it may become a very interesting event to extract information on the 
cometary outburst.

In addition, in 2021, the encounters of other dust trails ejected 
in 1988 and 1995 have been already shown in "Meteor Showers and their 
Parent Comets" by P. Jenniskens.
It was calculated by Shanov and Dubrovski.

Best wishes,

Mikiya Sato
mail at kaicho.net