Imaging Optics | Celestron C11 at f/10.3 |
Mount | Celestron CGE |
Guiding Software | MetaGuide |
Guiding Mode | Off-axis guiding with Taurus mini tracker |
Imaging Camera | Starlight Xpress SXVF-H9 |
Guiding Camera | Lumenera SKYnyx 2-0M @ 8 fps |
Guide Star | Approx Mag. 9.67 |
Collimation | MetaGuide |
Focus | MetaFocus |
Exposure Time | 18x15m |
Image Scale | 0.46" per pixel |
Raw FWHM | approx 2.0" |
Image Processing | Images Plus, flats, bias, darks. No Photoshop |
Image Acquisition | AstroArt |
Other Software | NexRemote, PECTool |
Location | Hudson Valley, NY |
Date | Sep. 19, 2008 |
Filter | Baader 7nm H-alpha |
Single 15m calibrated frame with linear stretch and no star correction
Close view of 4 stars from single exposure showing scale with 0.46" pixels
Close up of single star showing 0.46" pixels. Even at this image scale, the stars are small enough to make the fwhm value limited by the discrete sampling. Nonetheless, most of the star amplitude is in the central 1.5x1.5" square.
Field of view indicator in TheSky, for guidestar selection
View of camera and Taurus mini-tracker off-axis guider at back of C11, showing guidestar position angle indicator. To find guidestar, select it using field of view indicator in TheSky and note angle. Then set angle of the off-axis guider to the same value. Now center the object in the imaging camera, and the guidestar will appear on the video camera used by MetaGuide, where it is automatically selected and highlighted in realtime at 8 fps. Finally, calibrate the guider and commence guiding after fine tuning the framing of the object.
View of laptop screen during image acquisition, showing MetaGuide, AstroArt, and NexRemote. All imaging and control communication went over a single 32' long USB 2.0 cable to a USB hub, including the serial commands for controlling the telescope with NexRemote, and guiding with MetaGuide via ASCOM. Subsequent image processing is all in ImagesPlus 3.5. While autoguiding, the CGE has PEC playback enabled, previously trained by 8 periods using the free PECTool.