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comet plot


Denis Vien.

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Good evening to you all, well I think That There in not too many people on the forum, the sky is too good, but I have a question, I need the speed of the beautiful Catalina second arc RA and arc seconds in ED, I can not find it on the Sky Site or Otherwise.
I'll be a little more specific in my software of my horse, he tells me: Enter a speed in the Delta PR (right ascension) and DE (declination). These values indicate indication the deviation from the sidereal rate. You can determine the speed at qui the object moves relative to the stars in your planetarium software.
Once the speed has-been Entered, you can begin to follow at this speed by clicking close the comet icon in the toolbar.
Thanks for your feedback

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I use this site.

http://www.minorplanetcenter.net/iau/MPEph/MPEph.html

You enter the name of the comet, dates etc and your location. Further down the page you can ask for the movement of the comet/asteroid.

I wrote a spreadsheet to make this easier. The spreadsheet produces an object list that Autoslew can use to point to the object.

I can make the spreadsheet available if needed.

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Hi George,

 

you wrote "The spreadsheet produces an object list that Autoslew can use to point to the object."

That sounds if it might be a solution for tracking a really fast comet, or a even faster NearEarthObject passing by (maybe, the ISS  :) ).

 

For comets I just used the comet tracking provided by Autoslew. But this is insufficient for a NEO or the ISS, due to its changing arc speed during the passage.

 

So, it would be great, if you could make the spreadsheet available ! Together with some hints, how to feed the spreadsheet data into Autoslew...

 

Kind regards

Martin

 

P.S. Fine, at least Denis is lucky due to clear skies... we are suffering from cloudy nights here in central europe :(  but not worrying to much, due to the nearly full moon these nights.

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Other steps....  Put name of object in cells A1 and A2

 

You can remove the numbers 1,2....8 by clicking 'Clear Selection'.

 

I put my coordinates in cells B5 and E5 just to be handy for when I enter them in the ephemeris page. Clicking the link in B4 takes you to the ephemeris site.

 

Columns M and N show object altitude and Sun altitude. I have conditionally formatted the object altitude to be green if it is higher than 17 degrees for my observatory.

 

It is a good idea to Save the spreadsheet before you click on "Save object list". This is because the spreadsheet closes itself when the data is written. (I can't remember why I could not stop this happening).

 

The data is then written as an object list into ProgramData/ASA/Autoslew/MyObjectLists

Edited by GeorgeCarey
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A sample object list:

 

8
*****************************
Object Number 1
Object Name  20:50 Tue 19 Jan
Epoch: 2000
RA   : 13.5743055555556
DE   : 61.8066666666667
*****************************
Object Number 2
Object Name  21:00 Tue 19 Jan
Epoch: 2000
RA   : 13.5736111111111
DE   : 61.8247222222222
*****************************
Object Number 3
Object Name  21:10 Tue 19 Jan
Epoch: 2000
RA   : 13.5728888888889
DE   : 61.8425
*****************************
Object Number 4
Object Name  21:20 Tue 19 Jan
Epoch: 2000
RA   : 13.5721666666667
DE   : 61.8602777777778
*****************************
Object Number 5
Object Name  21:30 Tue 19 Jan
Epoch: 2000
RA   : 13.5714444444444
DE   : 61.8783333333333
*****************************
Object Number 6
Object Name  21:40 Tue 19 Jan
Epoch: 2000
RA   : 13.57075
DE   : 61.8961111111111
*****************************
Object Number 7
Object Name  21:50 Tue 19 Jan
Epoch: 2000
RA   : 13.5700277777778
DE   : 61.9141666666667
*****************************
Object Number 8
Object Name  22:00 Tue 19 Jan
Epoch: 2000
RA   : 13.5693055555556
DE   : 61.9319444444444
 

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Hi George,

 

excellent; thank you for all this detailed information, and the spreadsheet with hints.

Maybe I can find out, why the spreadsheet closes, after saving the Object List ;-)

 

I am still thinking about, how to synch the MaximDL exposure start and these slews from the Object List. Perhaps the next version of sequence supports such synchronization.

 

Up to now, I use comet tracking of Autoslew regularly, and it works very well.

The only obstacle for perfect pictures is, that when using the dither function in Autosave Setup of MaximDL, the target coordinates for every dither step are transmitted from MaximDL to Autoslew in absolut values, all dithered around the starting RA and DE values. This drives the mount back to the "dithered" coordinates of the first exposure every time. Though comet tracking still starts at this position then, the comet itself moves out of the image area, if it is to fast relative to the stars.

If the MaximDL dithering would send e.g. relative differences to the actual target position of the mount (not sure, if ASCOM allows this) or determine the actual position and apply the "dithering deviation" for calculating the new target position, it would thus lead to dithering for the photographed comet, which would remain in the same imaging area.

 

Do we know, if an Autoslew Object list supports comet tracking speed values beside RA and DE values for every object in the list ?

 

This would be an ideal solution for long time comet or ISS tracking, due to accepting changing speeds, at least from step to step.

 

Kind regards

Martin

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Yes, dithering on comets is a big problem. Maybe Philip Keller can incorporate this in a new version.

I think there was talk some time ago of a future version of Autoslew that would do what my spreadsheet does, automatically.

That is, to access the ephemeris directly, and also read the RA and DEC drifts. This would be the only way to do satellite tracking.

 

 

I think the problem of the spreadsheet closing was due to message boxes popping up. Asking for 'save as' file name or something.

I wrote it some years ago and just can't remember. If I look at the VB code it might come back to me.

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Hm... so I will await the new version of Autoslew and/or Sequence.

 

Btw, I found the code of the Module1, which has functions save() and savemanual(): the last line of the function is Application.Quit

That seems to be the reason for exiting when saving the object list.

 

Clears skies

Martin

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Hi Martin,

I removed the 'Application.Quit' and soon remembered why I put that in.

This is the error message when you try to close down/save the spreadsheet:

err.jpg

 

 

 

The last thing the spreadsheet did before close down was to save the object list with whatever name you gave it, as filetype .txt.

This is remembered, so when you shut down the spreadsheet it will prompt you to save it. If you say 'No' it will just close.

If you say Yes, then it tries to save the whole spreadsheet as filetype .txt with the last object list name.

This annoyed me so I added the Application.Quit. Not an elegant solution, I know.

 

I need to find the VB that will reset the 'Save as' parameters.

Edited by GeorgeCarey
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I think I have solved it. I reset the active worksheet which did not work at first but now seems OK.
If you want to save the spreadsheet you still have to reset the filetype, directory and filename, but that is not too bad.
At least when you close the spreadsheet now it does so without any messages.

http://geoastro.co.uk/object_list_planner_V21.xls

Edited by GeorgeCarey
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Georges Good evening,
Thank you so much for the spreadsheet, it was awesome, I could follow the beautiful Catalina, I will try to post it on the forum. Autoslew tracking the comet with no problems, it was very good. George thank you

Hello Martin yes here we have a beautiful sky his time, only one day of rain, the rest is clear. I'll try to post the comet on Catalina forum.affaire to follow, good evening
Denis Vien.

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