Bill Gray Feb 9, 2013
On 02/09/2013 02:46 PM, alessandro odasso wrote:
> I have found another asteroid in the same DSS plate:
>
> asteroid (4597) Consolmagno
>
> The measures are:
> 56 03 10.36875 261 12 30 50.55 +05 08 25.5
> 56 03 10.37431 261 12 30 50.29 +05 08 27.3
> 56 03 10.40556 261 12 30 48.82 +05 08 37.5
>
> Residuals:
> .05+ .03-
> .07+ .03-
> .05+ .02+
>
> the dT are as follows:
> -6.46 sec
> -8.70 sec
> -4.36 sec
>
> This seems to prove that the timing of the images is correct also for (6995) Minoyama.
>
> Looking at (6995) Minoyama I still wonder whether the 1956 astrometric measurements are correct or affected by some sistematic error: would this explain why the measures, though consistent, show those high residuals?
>
> An indipendent measure taken from some more expert person is really needed.
>
> Best wishes,
> Alessandro
>
>
>
>
>> Date: Thu, 7 Feb 2013 07:58:14 -0500
>> From: pluto@...
>> To: find_orb@yahoogroups.com
>> CC: alessandro_odasso@...
>> Subject: Re: [find_orb] (6995) Minoyama
>>
>> Hi Alessandro,
>>
>> Still a puzzler... here's what I'm getting, using the new version with
>> 300 asteroids :
>>
>> http://www.projectpluto.com/temp/mpec.htm
>>
>> Specifically, for your three observations, residuals are...
>>
>> 560310 261 3.35- 1.46+
>> 560310 261 3.39- 1.41+
>> 560310 261 3.36- 1.47+
>>
>> All very consistent with one another. The cross-residuals are
>> all under .1 arcsecond, with time residuals of about seven minutes.
>>
>> I'd have to say it's either a timing error of seven minutes for
>> all three plates, or an asteroid perturber that isn't among the 300
>> considered by Baer and Chesley. (This last possibility would be
>> very interesting indeed, if true, but I'd check the timing error
>> issue first.)
>>
>> I assume that if Jim Baer and Steve Chesley were able to find
>> 300 objects for which they could find perturbed asteroids with
>> measurable effects, then there must be a few more that can be
>> determined with more observations. Maybe you've found the 301st.
>> Unfortunately, I don't have software readily at hand to solve the
>> question, "what asteroids did (6995) approach between 1956 and 2012?"
>>
>> (Actually, I _can_ answer that for the 300 objects in BC-405,
>> using the same trick I used to determine that Pallas had perturbed
>> (70401). Turns out that (6995) also came close to (2) Pallas,
>> within .01 AU, in early 1968. And one does see a little "twitch" in
>> the residuals when asteroids are turned on as perturbers... not much
>> of one, though; the flyby was apparently a little too fast, distant,
>> and/or in the wrong direction to modify the orbit a lot.)
>>
>> -- Bill
>>
>> On 02/07/2013 01:26 AM, alessandro odasso wrote:
>>> Bill,
>>>
>>> many thanks for all faster than light response!
>>>
>>> You make me wonder whether I am wrong in the astrometry, but here is what I found:
>>>
>>> 1956 03 10.36875 12 42 59.07 +02 28 39.8
>>> 1956 03 10.37431 12 42 58.82 +02 28 41.3
>>> 1956 03 10.40556 12 42 57.43 +02 28 50.1
>>>
>>> --Alessandro
>
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