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MPCORB

Posted: 26 Mar 2020, 14:05
by nemesis83
I need to identify the location of a comet using the star atlas. I have down loaded the GSC and USNOB data bases. They work fine for stars and deep sky objects but not comets. The MPCORB database seems to be the answer. I have I think properly down loaded the MOCORB comet data base. Specifically, I want to work on calculating the mag for the C/2019 Y4 ATLAS comet but do not know how to identify it properly in the star atlas.

Also, could someone explain why there are three sets of RA, DEC coordinates in the star atlas RA, DEC box

Robert Yearley

Re: MPCORB

Posted: 27 Mar 2020, 05:11
by Dunmunro
nemesis83 wrote:
26 Mar 2020, 14:05
I need to identify the location of a comet using the star atlas. I have down loaded the GSC and USNOB data bases. They work fine for stars and deep sky objects but not comets. The MPCORB database seems to be the answer. I have I think properly down loaded the MOCORB comet data base. Specifically, I want to work on calculating the mag for the C/2019 Y4 ATLAS comet but do not know how to identify it properly in the star atlas.

Also, could someone explain why there are three sets of RA, DEC coordinates in the star atlas RA, DEC box

Robert Yearley
You need to download the file:

https://minorplanetcenter.net/iau/MPCORB/CometEls.txt

and place it in the directory pointed to in your Preferences->star Atlas->Minor planets folder. You also need to ensure the Show-> Comets box is checked along with Labels. You also have to click on the Minor planets button on the Star Atlas upper menu bar.

I only see one set of RA/Dec coordinates. There is also the Alt/Az coordinates.

I had some problems displaying comets using the 64bit executable. I had to open the 32bit LAA executable and display the comets there first and then they would display in the 64bit version.

Re: MPCORB

Posted: 30 Mar 2020, 07:16
by nemesis83
OK here goes.

1. Downloaded file ( looks like a txt file. selected "select all" and copied file. Saved file as MPCORB. In Minor planets inputted D:\Temp\MPC\. Made sure that MPCORB was in the MPC folder.
2. opened AA7 opened Tools>Star Atlas. Went to find. clicked on Open MPCORB-panel greyed out-no errors.
3. clicked on Minor Planets - none showed up.
4, Attempted to find a comet but have no idea how to call it in the Object or RA,DEC box. By the way I can put in comet RA,Dec from Stellarium and the Star Atlas will go to it.
5. Either I have not loaded MPCORB correctly or I simply do not know to call a comet by whatever name needed.

Re: MPCORB

Posted: 30 Mar 2020, 18:20
by Dunmunro
nemesis83 wrote:
30 Mar 2020, 07:16
OK here goes.

1. Downloaded file ( looks like a txt file. selected "select all" and copied file. Saved file as MPCORB. In Minor planets inputted D:\Temp\MPC\. Made sure that MPCORB was in the MPC folder.
2. opened AA7 opened Tools>Star Atlas. Went to find. clicked on Open MPCORB-panel greyed out-no errors.
3. clicked on Minor Planets - none showed up.
4, Attempted to find a comet but have no idea how to call it in the Object or RA,DEC box. By the way I can put in comet RA,Dec from Stellarium and the Star Atlas will go to it.
5. Either I have not loaded MPCORB correctly or I simply do not know to call a comet by whatever name needed.
You save the file with it's original name and extension: CometEls.txt

If all works well you can zoom the Star Atlas out and all visible comets will show.

Re: MPCORB

Posted: 30 Mar 2020, 18:57
by nemesis83
Dunnunro,

Many thanks, that fixed the problem.

nemesis83

Re: MPCORB

Posted: 05 Apr 2020, 09:09
by Gilbert
Bonjour à tous !
Merci pour votre expertise !
Effectivement il faut bien respecter les noms tel que "CometEls.txt" avec L'extension ". txt"
Du coup cela fonctionne également chez moi.
Bien cordialement