[neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems

[Jonathan McDowell]

Yes, I'd like to reiterate that the community owes a big debt to Bill.
The observer community are not in a position to complain when things aren't
perfect.
(At least not to Bill...  it is of course ridiculous that there is no
serious funded and long-term-planned effort to do this work.)
 - Jonathan

On Fri, 28 Aug 2020 at 15:24, Bill J. Gray <pluto at projectpluto.com> wrote:

> Hi Sam, all,
>
> On 8/28/20 6:19 AM, Sam Deen via groups.io wrote:
> >
> > You'd think they'd have learned after two accidental finds just two days
> ago, wouldn't you?
>
>     Well... that's mostly on me,  I'm afraid.
>
>     For the first "find" of OGO-1,  I have a decent excuse.  We've
> had pretty good TLEs and lots of data for this object for the last
> five years.  Generally speaking,  we've known where it was.  But
> during late August,  it had just enough drag to make it difficult
> to predict.  I'd have told you that we just had rough guesses as
> to where it might be.  For all I knew,  it might have already
> re-entered.  The data were actually quite good -- thank you,
> Goran Gašparović! -- but I wasn't too sure how well the theoretical
> modelling of grazing atmospheric passes would match reality.
>
>     As it turned out,  I was overly pessimistic.  The first
> "find" was within about two degrees of prediction.  But
> that wouldn't really have been close enough to be considered
> a match,  and the object would have ended up on NEOCP anyway.
>
>     For the second "find" (ZTF0ENg),  I don't have such a good
> alibi.  If I'd posted TLEs from before the recent perigee
> at 27.63 August,  with "guessed" AMR=0.03,  the object would
> have been within 7' of prediction.  If I'd been quick about
> posting TLEs after that,  we'd be good to arcseconds.  So
> yes,  that one did slip by.
>
>     The TLEs used for this identification are posted to my
> GitHub site,
>
> https://github.com/Bill-Gray/tles
>
>     with the TLEs for this particular object updated a couple
> of minutes ago.  MPC will pull those changes in a few hours;
> after that,  the object ought to be safe from NEOCP posting.
>
>     I should note that the tracking of such objects is indeed
> somewhat "casual".  I get observations mostly from amateurs.
> It's been a hobby for me.  Given all that,  we've been doing
> reasonably well.
>
> -- Bill
>
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