(meteorobs) Eta Aquariids 2007

[Mikiya Sato]

Dear all,

I am Mikiya Sato. I was not sending mail for a long time, sorry!

I calculated the trail of Eta Aquariids in 2007, as already announced
 by CBET 944 and Quanzhi's mail.
Two parts of a trail that was ejected from 1P/Halley in -835 (836 BC)
 will approach to the Earth, about May 6.6.
The outline is as follows.

E.Y   DATE (UT) TIME   LS     Delta-r  Ej.V  fM    RP-Alp. Del. Vg(km/s)
-835  May.06.56 13:28 45.553 +0.00068 -20.29 0.018 337.72 -0.91 65.93
-835  May.06.62 14:57 45.613 -0.00010 -20.26 0.046 337.76 -0.89 65.95
*Ej.V: Ejection Velocity (m/s)

This trail is very old and the shape is very complex due to
 perturbations of Jupiter. So the peak will not be sharp,
 a long peak might be observed.

But, it is difficult to guess the activity because the detail
 of other years was not calculated. 
Moreover, the fM value of this Aquariids is smaller than the
 value of another trails of last Orionids. And the usual ZHR of
 Eta Aquariids is very high (about 60? at the southern hemisphere),
 so the peak might not be separated if the activity of this peak
 is a low level.

However, it is a good opportunity that the influence of the dust
 trail from 1P/Halley can be observed. In Japan, the observation
 condition is not so good. 
So, I hope to be observed at the wide region in the world.

Please refer to the following my web for a figure etc.

http://fas.kaicho.net/tenshow/meteor/1p2007/EAqr2007.htm

Best wishes,

Mikiya Sato
mail at kaicho.net