Topics

#astrophotography #iexos-100 #EXOS2 #iEXOS-100 #EXOS2 #astrophotography


Max <asanmax@...>
 

Hello everyone,

Could be a long shot, but has anyone tried imaging comets on either iExos-100 or EXES2 using the PHD2 comet tracking feature?
I would like to try this but it's been cloudy here for over a month and for now I'm just trying to find if anyone had any experience.

Thanks!


Wes Mcdonald
 

Max

Dr. Clay sherrod at arksky.org Arkansas sky observatory publishes ephemeris for comets etc.  Generally I guess you can poke in the ra/Dec to point the mount.  The rates won't be right though.  Perhaps PhD will guide you along.  Somewhere Jerry made a post about this.  SkySafari has these things and I wonder if it would drive the mount.  If I have time I will give it a go.  Same with satellites.  I wonder.

Wes

--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


Max <asanmax@...>
 

Thanks Wes, it looks like PHD2 could do a good job on 'poking' the mount to track the slowly moving comet.
I'd love to give it a try but again, those clouds drive me crazy...


Wes Mcdonald
 

Max
I tried out SkySafari.  It is great for going to the comets and other objects it has.  Will send the mount right to them....but it does not update the mount apparently.  So the mount begins to diverge from the object with rate depending on it's proper motion.  Pan stars moves very slowly away from the mount pointing.  Pressing go-to again in SkySafari updates the mount and puts things back, but they begin to move away again.

I doubt stellarium will do any better.  There might be an ascom app out there that would implement a series of pointing instructions to the mount.  I don't know if the PMC 8 can be told to follow a trajectory of velocity in Ra/dec, if that is even a thing in ascom language.  

Anyhow you can definitely use SkySafari to get on these objects and maybe use PhD to boot you along if the object is visible in the guide scope and has a centroid. Pretty sure my 80mm could be used to guide brighter comets but I don't have it fixtured on the mount....don't know if my 60mm guide scope could.

Wes



--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


Max <asanmax@...>
 

Thanks Wes, I'm sure there should be an application that will adjust the tracking rate to offset the comet position. One of them is HORIZONS for Astrophysics mounts, it uses ephemeris import tool in EQMOD.

I am interested to try the PHD2 comet tracking tool: https://openphdguiding.org/man-dev/Tools.htm#Comet_Tracking

There are a three different ways to provide the comet tracking rate to PHD2.

  • Some planetarium applications, like Cartes du Ciel, can send the rate directly to PHD2;
  • You can enter the tracking rate manually, or,
  • You can train the rate in PHD2 by following the comet for a period of time in the imaging camera.
Looks like the option with Cartes du Ciel should be relatively easy to use.


Wes Mcdonald
 

Max

Yes.  A friend of mine on the forum sent me this link that discussed exactly what you mention:


I think I would go with regular PHD and use an off axis guider to take advantage of the full scope aperture.  Probably could guide on the core of a comet.

Wes





--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired