[Neocp_artsats] Various recent junk on NEOCP

[Bill Gray]

Hi folks,

    C44DVA1 = C44C831.  I also dug out a tracklet,  C44ALU1,  from the 
'miscellaneous artsat astrometry' file.  I _think_ this is Multijunk. 
But we've not actually seen that object for a while,  so I'm not 100% 
sure of that yet.  I've added it as a new object until I do have that 
level of confidence.

    A11izBZ = Gaia.  This one shouldn't have slid past me.

    Gaia maneuvered in mid-January,  and was on NEOCP as xkos447 and 
removed Jan 24.  The Horizons ephems assumed it would remain at the 
earth-sun L1 point for about another year.  ESA did provide state 
vectors,  but they were password-protected.  So I generated ephems based 
on what little astrometry I had at the time and posted TLEs based on those.

    That sufficed for a bit over a week.  At that point,  Gaia had 
departed enough from prediction for it to fail,  causing A11izBZ to get 
on to NEOCP.

    Fortunately,  Horizons now _does_ have corrected ephems,  and I've 
updated TLEs to match.

    I strongly suspect that A11ilIA is junk,  and that the (Q06) 
follow-up is spurious.  Adding in that tracklet requires greater 
cross-track residuals than seems reasonable for ATLAS.  I can't prove 
it,  though.  The ATLAS arc is short enough to allow for heliocentric 
solutions,  though again,  the fit isn't great.

    A11izBQ,  A11itwS, and A11izBT all look to be probable (but not 
certain) one-day artsats,  probably ETBOs.

-- Bill