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(meteorobs) Visual meteors unobservable from 1997 XF11
It has been about a decade since I calculated a meteor radiant, and I had
to resurrect a Commodore 64 program to make the calculation!
Unfortunately, the asteroid (and thus any associated debris) would approach
the Earth from the direction of the Sun, so there is very little possibility
of any visual meteors. The circumstances are calculated using the orbital
elements from the linked 1990-1998 orbit, integrated (compensated for
planetary perturbations) to 2028 Oct 26, but could be applicable to this
day in any year.
Radiant RA 220 deg Dec -6 deg (2000)
V(inf) 14.3 km/s
V(atm) 18.1 km/s
Elongation from Sun 12 deg
The atmospheric velocity is the observed velocity of meteors (or the
asteroid were it to ever hit the Earth at this node), which adds the
Earth's gravitational attraction to the "unattracted" velocity (V infinity).
This gravational attraction on the low velocity meteors could cause a
zenithal attraction of the radiant of up to 14 degrees (this being the
value needed to place the radiant on the horizon). At some optimal latitude
(probably low northern hemisphere, as the radiant is north and east of the
Sun), meteors could still be seen until the Sun had set 12 + 14 = 26 deg
below the western horizon. In practical terms, this is not a visual shower,
even if there happened to be debris near the asteroid or distributed around
the orbit!
Cheers, Rob McNaught
(rmn@aaocbn.aaodot gov.au)