(meteorobs) New possible parent comet

[Mikhail Maslov]

>> Interesting news! Thanks to Mikhail's work, and could you tell me
>> when will the Earth pass the "point"?

DD> I also noticed the interesting orbit of this comet yesterday and played 
DD> around with it a little.  It turns out the comet is late by 38 days.  
DD> That means, if it has passed the perihelion on July 22nd instead of 
DD> August 30th, then we would have had a close approach to 0.026 a.u. on 
DD> July 30th-31st.

DD> Indeed, P/2004 R1 (McNaught) is currently listed among Potencially 
DD> Hazardous Comets at http://neo.jpl.nasa.gov/cgi-bin/neo_elem?type=NEC at 
DD> rank 6 if you sort 'em by MOID (min. orbit intersection distance).  But 
DD> still it's MOID is 3 times larger than that of 55P/Tempel-Tuttle and 30 
DD> times as compared to  109P/Swift-Tuttle.  Another point which makes 
DD> meteor activity from this comet very unlikely is intrinsic faintness of 
DD> 2004 R1.  If I'm correct, its current brightness suggests an absolute 
DD> magnitude of only 18.5.  This means there's a very little material left 
DD> of this comet after its 1990 approach to Jupiter.

Concerning MOIDs, let's don't forget, that the orbit of both the comet
and trails are not stable. Even without close approaches
to planets, they continiously suffer small alterations, which could be
crucial for meteor activity occurance. For instance, the perihelion
distance of the comet during 2004-2047 varys between 0.974 and 0.994
a.e. for given elements. Difference in 0.001 a.e may be very essential
for meteoric activity. In case of 55P, let me remember, that
recent storms and enhancements were caused by trails of 4,5,...
revolutions, while MOIDs are related to current orbital elements.
Speaking of small size of the comet, of course, any trails it ejects
should be very slim, so the terms of shower occurance are very strict,
much more than for Leonids and Giacobinids.

And another remark. Rough estimations for two points of intersection
shows the suggested shower could be active around 26 June and 10
August with radiants between Virgo and Libra several degrees below
ecliptic.

Best regards, Mikhail Maslov.