(meteorobs) Meteor Activity Outlook for November 5-11, 2011 - NTA and 2004 TG10

[metpaper at Safe-mail.net]

-------- Original Message --------
From: Robert Lunsford <lunro.imo.usa at cox.net>

> The Northern Taurids (NTA) are active from a large radiant centered at 03:35 (054) +22. This position lies in western Taurus, three degrees southwest of the famous naked eye cluster known as the Pleiades (seven sisters). The radiant is best placed near 0100 LST, when it lies highest above the horizon. Since the radiant is large, Northern Taurid meteors may also appear to come from Aries, southern Perseus, as well as western Taurus. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity. Expected rates would be near two per hour, no matter your location.
> 

This shower's been recently associated with 2004TG10, an "asteroid", probably a Near Earth One, but there's nothing to say it isn't a defunct comet (akin to the 3200 Phaethon and Geminid situation).

Traditionally it used to be associated with 2P/Encke, although the orbits never really matched all that well.

Things is, I followed the papers as best I could in the online archives on astro-ph or personal professional websites, and as often happens there's a lot of mentioning of the association but none of the papers seem to be the discovery and/or defining paper.  There're some public blogs and websites that note it too, but don't seem to carry original source.

Similar, the concept that 2004 TG10 is a "bit" of 2P/Encke seems to be just taken for granted, rather than shown, whereas the orbits are disimilar, albeit not totally so, but low inclination ecliptic objects in Earth crossing orbits can have no more commonality than sharing a similar injection mechanism (usually Jupiter...).

Whatever, _lots_ of SonotaCo both identified as NTAs and as sporadics orbits match the 2004 TG10 orbit incredibly well and closely, wherease those for 2P/Encke are quite discrete (I don't have access to all known and assumed [via numerical integration] past orbits of 2P/Encke, remembering 2P/Encke and assumed bits thereof has been the "hero" of several catastrophic extinction theories and impact events, not excluding Tunguska, over a long period) from these objects' orbits.  Stepping back from dramatic interpretations and just looking at the object, it's orbit, and the orbit of the meteors, one can see how a NEO that does populate our local orbital space with debris manifests itself in terms of Earth incident meteors, their population index (ie brightness range), temporal distribution and radiant tightness, and of course percentage of fireballs relative to non-fireballs, and the colour thereof.

The tinypic url below shows the SonotaCo orbits graphically with the 2004 TG10 one so buried amongst them that it is indistinguishable in this plot.  The outermost plotted planetary orbit is that of Jupiter, note the aphelia cluster towards there within the context of injection.  In this case the parent body is more likely to be a defunct Jupiter Family Comet than something chucked in from the Main Belt of Asteroids, however as I say I haven't yet found the primary source of identification of association, the one that is listed usually as first reference even reads in its abstract as if the association was already known prior to that paper's research.

http://oi40.tinypic.com/25q6c8k.jpg

Cheers

John