Re (addition 2): [meteorite-list] re: One Find, Two Astronomers:An Ethical Brawl

From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Sun Sep 18 18:31:57 2005
Message-ID: <432DEABA.36D7BB86_at_bhil.com>

Hi, Marco

    While I am far from a working knowledge
of the astrometric procedures, no practical
experience doing so, in other words, I note
that in addition to the the rough pointing data
you refer to, it appears that among the files
accessed were the ccd processing logs.

    As I said earlier: "the ccd processing logs...
are crucial too because they identify K40506A
in the field coordinates,"

    That is to say objects are identified by pixel
coordinates, i.e., 782, 349. If you have read the
specification of their ccd, say, a 1024 square
pixel array, you are able to pinpoint the position
of K40506A in the field. If then, there are other
identified objects, such as stars (which there
are) with pixel coordinates, one is able by
interpolation to fix the position of K40506A to
a high degree of precision and a fair degree of
accuracy (the two not being the same) for a
given time of exposure (which is also in those
logs).

    Even I, a refugee from the pre-calculator era,
could do it with no resources beyond a sharp
pencil... That is why I said the access of those
logs was significant.

    But, the matter is essentially a dead issue,
important primarily to the individuals involved.
I am much more interested in 2003EL61 itself!
Its shape, for example. Now, there's a puzzle
worthy of puzzlement.

Sterling K. Webb
-----------------------------------------------------------------------
Marco Langbroek wrote:

> Sterling also wrote:
>
> > Stoss uses NEAT data, DSS and POSS data, to
> > refine the orbit. He never uses Brown's data? Wouldn't
> > that help refine it?
>
> Not at all, because the telescope log data provide you with only rough telescope
> pointing positions, not the arcsecond accuracy object positions Ortiz' data,
> NEAT data, DSS and POSS provided. With the Ortiz, NEAT, DSS and POSS data
> available through Ortiz' and Stoss observing data and Stoss's image archive
> precovery activities, the addition of Browns/SMARTS telescope log data would not
> have improved the orbital solution at all (rather, it would probably have
> worsened it). The SMARTS log did not contain astrometry for the object, only
> rough telescope pointing locations.
>
> > Yet, 20 minutes after the times of
> > his own Mallorca observations and recovery of the
> > object, someone at IAA is accessing Brown's positional
> > data AGAIN.
> >
> > I am most curious. Why? Are they merely "curious"?
> > At this point, they have discovery positions (2003),
> > archival positions (NEAT, etc.), and current position
> > (Mallorca) of "their" object. Why check someone else's
> > data if you are not going to use it and claim that you
> > are not even sure if it's the same object?
>
> As explained above, with the data they HAD at that time, Brown's data would not
> have contributed anything valid at all to what they already had. Hence, this
> MUST have been curiosity, yes. And understandable. There is that mysterious
> reference to an "object" that could or could not be the same. It is
> understandable that you compare the little that is known about that object to
> your data.
>
> > In fact, with what orbital
> > data they already have, they can easily determine
> > from Brown's data accessed the first time that it
> > IS the same.
>
> They could determine that it was very likely to concern the same object. Which
> is interesting, but holds no further meaning. Curiosity could very easily lead
> to further comparison. The fact that they accessed the data again after
> accumulating a much larger and much more accurate body of data themselves,
> points out that they did not acces the data in order to use it, but rather to
> compare. This strongly suggest the question behind this was: "is it really the
> same object?". By contrast, if Browns data would have been the starting point
> for finding the object in the first place, they would not have had to question
> whether it was the same object.... For the rest, I refer to my previous mails.
>
> - Marco
>
> -----
> Dr Marco Langbroek
> Leiden, The Netherlands
>
> Volunteer image reviewer FMO Spacewatch Project
> NEAT archive hunter
> Admin FMO Mailing List
>
> e-mail: meteorites_at_dmsweb.org
> private website http://home.wanadoo.nl/marco.langbroek/asteroid.html
> FMO Mailing List website: http://home.wanadoo.nl/marco.langbroek/fmo.html
> -----
Received on Sun 18 Sep 2005 06:31:22 PM PDT