Home    My Setup    Sky objects    Monthly    Kid's Page    Miscellaneous    Sales    Links    Say 'Hi'

 

Comet Positions in GUIDE 8.0 verses The Sky 6 Software

I've been having trouble using The Sky 6 to centre comets when doing comet astrometry with a 14" (35cm) f10 Meade ACF SCT on a Paramount ME. I use a SBIG STL11000M CCD (35mm chip) for imaging the comets. I've found that when I update the orbital elements in both programmes that GUIDE is always spot on - the comet is exactly where it should be. However The Sky 6 comets are well off in position - so much so that they lie outside the FOV at times. Indeed, to use CCDCommander to auto-slew to the comets in Sky I have to find the closest star and enter the SAO or GSC number so that the telescope slews to that field and I manage to get the comet. Below are some screen shots of Guide verses Sky and images of the actual comets for comparisom...

(Bear in mind that The Sky6 is a great programme for telescope control and information. Perhaps I am doing someting wrong at my end to render the predicted positions useless)

Click on the images for a larger version
Predicted position of C/2011R1 (McNaught) from GUIDE 8
Actual imaged position of C/2011R1 (McNaught) based on GUIDE 8
Predicted position of C/2011R1 (McNaught) from The Sky6
Actual imaged position of C/2011R1 (McNaught) based on Sky6
Predicted position of C/2010G2 (Hill) from GUIDE8
Actual imaged position of C/2010G2 (Hill) based on GUIDE8
Predicted position of C/2010G2 (Hill) from The Sky6
Actual imaged position of C/2010G2 (Hill) based on Sky6
Orbital elements of C/2010G2 (Hill) - Guide8 - note that the date of perihelion matches that of Element Epoch in The Sky 6
Orbital elements of C/2010G2 (Hill) - Sky6 - note that the Element Epoch in The Sky 6 matches the Date of Perihelion in Guide8
Predicted position of C/2009F4 (McNaught) from GUIDE8
Actual imaged position of C/2009F4 (McNaught) based on GUIDE8
Predicted position of C/2009F4 (McNaught) from The Sky6
Actual imaged position of C/2009F4 (McNaught) based on The Sky6
Orbital elements of C/2009F4 (McNaught) - Guide8 - note that the date of perihelion matches that of Element Epoch in The Sky 6
Orbital elements of C/2009F4 (McNaught) - Sky6 - note that the Element Epoch in The Sky 6 matches the Date of Perihelion in Guide8