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MetaGuide: Bubble Nebula in Ha, with equipment details and star analysis

Imaging OpticsCelestron C11 at f/10.3
MountCelestron CGE
Guiding SoftwareMetaGuide
Guiding ModeOff-axis guiding with Taurus mini tracker
Imaging CameraStarlight Xpress SXVF-H9
Guiding CameraLumenera SKYnyx 2-0M @ 8 fps
Guide StarApprox Mag. 9.67
Exposure Time18x15m
Image Scale0.46" per pixel
Raw FWHMapprox 2.0"
Image ProcessingImages Plus, flats, bias, darks. No Photoshop
Image AcquisitionAstroArt
Other SoftwareNexRemote, PECTool
LocationHudson Valley, NY
DateSep. 19, 2008
FilterBaader 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.