Re: [guide-user] Re: Adding Comets

Bill Gray Nov 5, 2015

Hi Clay,

Removing it permanently would present a major problem: you
would get only those comets MPC happens to be keeping track of,
plus those Guide knew about when the disks were made. You would
get horribly incorrect epochs (because the data would be the old
stuff from the DVD, not the new stuff from IMCCE), and a lot of
missing objects (those found after the DVDs were made, but not
recently enough that MPC is still putting them in their lists.)

For the nonce, downloading the 'eltdat_g.txt' file mentioned in
my previous e-mail will fill in the missing objects. But the
continued absence of IMCCE is going to cause trouble.

I'm considering a couple of possible workarounds. One would be
for me to provide my own comet elements. I'm now able to get the
MPC's file of comet astrometry and compute orbits myself for all
objects in it. Essentially, I'd be providing a comet version of
what Lowell's ASTORB and MPC's MPCORB provide for asteroids.

This wouldn't be all that difficult for me to do, but keeping
it up to date would be a nuisance. So I'm sort of hoping to avoid
doing this. But it may be unavoidable.

-- Bill

On 11/05/2015 02:58 PM, 'P. Clay Sherrod' drclay@... [guide-user] wrote:
> Interesting that you are noting the silence of IMCCE.....from the very
> first date that this change was made, I had trouble getting comet data
> consistently with that link to IMCCE; it would never complete the
> download, or connection could not be even made.
> Nearly every night the comet data was all over the place, with missing
> comets, horribly incorrect epochs and other mistakes.
>
> When the "Use Only MPC...." function/link was added through some gentle
> pursuasion, things worked just fine and downloads have been accurate
> and swift, no problems.
>
> I suggest that the IMCCE link be removed completely from Guide.
>
> ------------
> Dr. Clay
>
> Arkansas Sky Observatories
> http://www.arksky.org/
> ASO Petit Jean Mountain /MPC H41
> ASO Petit Jean Mountain South /MPC H45
> ASO West Conway /MPC H43
> .......serving astronomy since 1971
> ____________________
> ----- Original Message -----
> From: "Bill Gray pluto@... [guide-user]" <guide-user@yahoogroups.com>
> To: <guide-user@yahoogroups.com>
> Sent: Thursday, November 05, 2015 1:36 PM
> Subject: Re: [guide-user] Re: Adding Comets
>
>
>> Hi David,
>>
>> Simplest way to fix this :
>>
>> (1) Make sure you're using the version of the Guide 9 software from
>>
>> http://www.projectpluto.com/new.htm
>>
>> You will see, among other improvements, "(2012 December 12) Fixes
>> and improved display of comets". Which is partly why I recommend getting
>> this version.
>>
>> (2) The "improvement" involved having Guide use comet orbital data
>> from the IMCCE in France, plus the Minor Planet Center's comet data.
>> The only sticky bit is that the IMCCE has gone silent, causing Guide's
>> automatic comet retrieval to break. (As you found.)
>>
>> So instead, try downloading this file:
>>
>> http://www.projectpluto.com/eltdat_g.txt
>>
>> (about 193 KBytes) to your Guide folder. This is the last version
>> of the IMCCE data, from August 2015.
>>
>> Then, download the MPC file directly :
>>
>> http://www.minorplanetcenter.net/iau/Ephemerides/Comets/Soft02Cmt.txt
>>
>> And save it to your Guide folder... _changing the name to
>> soft02cm.txt_, i.e., drop a 't' from the name. Upper vs. lowercase
>> doesn't matter, at least not in Windows.
>>
>> -- Bill
>>
>> On 11/05/2015 02:01 PM, stonedoffmyass@... [guide-user] wrote:
>>>
>>>
>>> I solved my own issue.( kind of )
>>>
>>> After careful review of the orbital elements and their entries,
>>>
>>> One laptop I have magically took the orbital elements ,the other machine refuses
>>> to accept these new Comets.
>>>
>>> At least I can "add a trail" , and print the chart displaying added Comet now.
>>>
>>> Will settle for that for now
>>>
>>>
>>> David
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>> ------------------------------------
>> Posted by: Bill Gray <pluto@...>
>> ------------------------------------
>>
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>>
>
>
>
> ------------------------------------
> Posted by: "P. Clay Sherrod" <drclay@...>
> ------------------------------------
>
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