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(meteorobs) Fwd: [IMO-News] 2003 Pi-Puppids
NOTE: Forwarded without Jeremie's permission.
-----Original Message-----
From: Jeremie Vaubaillon <vaubaill@imcce.fr>
Sent: Thursday, April 03, 2003 1:18 PM
Subject: [IMO-News] 2003 Pi-Puppids
Hello you all,
A pi-puppids meteor "shower" will happend on April 23rd, 15:00 UT +- 1:00. But
particles
are expected to be very tiny. So the profile will probably be large: total
duration of the
shower: 7 hours (that is why the uncertainty on the Max. time is so important)
So please, every visual, but especially radio meteor observers are asked to
observe
carefully around this date.
The regions of the world concerned by this shower are located in south
hemisphere.
But as the coordinates of the radiant are : alpha = 110°, delta = -45°, it is
possible to
have echoes in North hemisphere too (south of Europe, India, Central America,
USA, etc.).
Our results suggest that past Pi-Puppids meteor showers have often been missed
due to poor
observing coverage. So I would like to draw your attention to the necessity of
having (even
few) results (exactly as Esko Lyytinen and Peter Jenniskens' prediction last
March).
In particular, though Australia and New Zealand are not the best situated
regions, radio
observations are welcomed, as they can be done night and day. I also recall you
that we
predict a long duration shower (compare to Leonids for example).
This result has already been submitted to A&A in last february, but we have
still lots of
changes to add in the actual version of the article before it can be accepted.
Our work has been initialized by a first study made by Scott Messenger (M&PS,
37,
1491-1505, 2002). Messenger is a specialist of interplanetary dust, and has
already
conducted some expedition to Antartica to collect some micrometeorites.
His study is simple, but the big advantage is that it is fast (keplerian orbits
perturbed
by radiative forces). He has found 2 peaks on 23rd April 2003. He has simulated
600,000
particles in the size range [20-100 micron]. But he considered only the comet
returns in
the 1967-1997 period, as initial condition for the ejection of the dust. His
work has
encouraged us to look further, and was a very good first step towards accurate
forecastings.
We have done the same study as for leonids
(http://www.imcce.fr/s2p/leonides/predictions/Leonid_forecast.html).
The differences between our approach and Messenger's is that our model is far
more complete
and takes into account gravitational perturbations induced by all planets, as
well as
radiative forces.
We took 960,000 particles in the size range [50 micron - 1 mm], ejected from
1848 to 2002
(that makes 32 perihelion returns), and have associated the pi-puppids showers
of 1972,
1977 and 1982 with streams of the 19th and 20th centuary. The coming shower is
associated
with the1957 and 1961 streams, but we have found a SINGLE peak. This means that
the 2
streams overlap.
We have also underlined how encounters with Jupiter have strong consequences on
the
evolution of the streams.
Further explanations, as well as movies explaning the evolution of Pi-Puppids
can be found
at:
www.imcce.fr/s2p/puppids/
As the article is stil now not finished, it can be interesting to add
obsevration results.
Please, do not hesitate to braodcast this information and to contact us ;-)
Thanks a lot to any observer !!!
Best wishes.
Jeremie VAUBAILLON
--
************************************************************
* Jeremie VAUBAILLON
* Institut de Mecanique Celeste et de Calcul
* des Ephemerides (www.imcce.fr, ex bdl.fr)
* 77 Avenue Denfert Rochereau
* 75014 PARIS
* FRANCE
************************************************************
* tel : +33 (0)1 40 51 22 66
* fax : +33 (0)1 40 51 20 58
* URL : http://www.imcce.fr/Equipes/GAP/equipeGAP-jv-GB.html
************************************************************
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