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Recommendations for Comet Plotting Software

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#1 careysub

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Posted 14 July 2013 - 01:33 PM

When Comet ISON makes its perihelion dive on Thanksgiving Day, I would like to be able to observe it safely with a tracking sun-shield that keeps its edge close to the comet nucleus on the sun-ward side.

To do this I need to be able to accurately predict the position of both the sun and the comet in my sky - down to the very fast perihelion pinturn (I expect the nuclear region becomes non-observable at closest approach).

Being able to produce plots of the apparent comet movement in a sun-centered view as well as plots of both sun and comet in the sky would be useful.

Any recommendations for the best software for this purpose?

Such a tracking sun-mask system would be useful for daytime observing of Mercury and Venus also.

#2 Matthew Ota

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Posted 15 July 2013 - 01:30 AM

I use TheSky to track comets and asteroids. TheSky enabled me to take this image of Comet 2006P1 McNaught in broad daylight:

OCA Web Gallery: Comets

#3 rmollise

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Posted 15 July 2013 - 08:49 AM

When Comet ISON makes its perihelion dive on Thanksgiving Day, I would like to be able to observe it safely with a tracking sun-shield that keeps its edge close to the comet nucleus on the sun-ward side.

To do this I need to be able to accurately predict the position of both the sun and the comet in my sky - down to the very fast perihelion pinturn (I expect the nuclear region becomes non-observable at closest approach).

Being able to produce plots of the apparent comet movement in a sun-centered view as well as plots of both sun and comet in the sky would be useful.

Any recommendations for the best software for this purpose?

Such a tracking sun-mask system would be useful for daytime observing of Mercury and Venus also.


Almost any software can do this, including the (free) Cartes du Ciel. ;)

#4 PhilCo126

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Posted 25 August 2013 - 11:26 AM

Euh... Stellarium can't ?

#5 rmollise

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Posted 25 August 2013 - 03:10 PM

Euh... Stellarium can't ?


Oh yes it can. You may be using an old version, or just haven't looked at the routine, which is found in "plug-ins"... ;)

It wouldn't be my choice for comets, and it would be easier with Cartes, but you can do it well enough.

#6 Mark9473

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Posted 25 August 2013 - 05:10 PM

Isn't this the same problem as we had with that NEO passage early in the year? The commonly available orbital elements, that these planetarium programs have access to, won't correctly calculate a passage through a strong gravitational field. I thought at the time SkySafari stood out as having a (slightly simplified) algorithm for calculating the effects of the gravitational pull.

Whatever program you use, you'd have to check that the orbital elements it imports are calculated to include the close passage to the Sun.

#7 btschumy

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Posted 25 August 2013 - 06:05 PM

Mark,

You are correct that SkySafari has special code to calculate the perturbed orbit of a NEO as it passes close to Earth. This is needed because the object is not actually orbiting Earth. However, because ISON does orbit the Sun, it is not being perturbed and the standard orbital elements should give an accurate prediction.

Bill

#8 BSJ

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Posted 26 August 2013 - 05:11 PM

If you doubt the position, just download the latest data.

Easy pieesee with Stellarium
...

#9 Mike Phillips

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Posted 28 August 2013 - 03:15 PM

Almost any software can do this, including the (free) Cartes du Ciel. ;)


Seconded! Typically I just go straight to MPC and get the ephem!

Mike

#10 PhilCo126

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Posted 29 August 2013 - 02:21 PM

Software packages theSkyX and SkyMap Pro are regularly mentioned as comet plotting software of choice... to help decide how long a subexposure at the comet's motion can be...


:thinking: :gotpopcorn:

#11 rmollise

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Posted 30 August 2013 - 09:05 AM

TheSky is fine. I don't note that it's any better than CdC in this regard, though, and, frankly, I find the comet tools in TheSky 6 not as good. Plus, I just fraking like "free." :lol:






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