Sunday, September 20, 2009

Milky Way Widefield, Bubble Nebula, Eagle Nebula / Pillars of Creation (M16), Lagoon Nebula (M8)

This viewing session was out at Moose Creek again and the new Moon gave the evening a great start. I left the city about 6:00PM and arrived with time to get mostly setup prior to dusk.

Temperatures were forcasted to be just below 10degrees C.

Setup was a Celestron 11 inch schmidt cassegrain telescope for imaging into a QHY 8 CCD camera. Piggybacked was a Willam Optics 90mm Megres refractor for autoguiding into a Meade Deep Sky Imager. Wide field images were taken with a Canon 10D DSLR through a Canon fixed length 50mm f/1.4 lens. Mount was a stock Celestron CGE mount.

Mount was orientated due north by compass and leveled by bubble. I do not adjust the vertical (altitude) of the mount from home to Moose Cr, so, polar alignment was as very easy as usual. When the mount attempts to align to the first alignment star I manually move the mount in
azimuth to best center the target star in the finder. I follow this by the usual completion of the two star alignment. Since the mount is provided with long / lat coordinates and time, this manual adjustment in azimuth is equivelent to polar alignment. Even though this is not sufficient for unguided astrophotography, it is sufficient for goto functions and guided astrophotography.

Focus of DSI and QHY CCD was done with Nebulosity. Half width flux were low to medium 2.0's

Focus of the 10D was done by allowing the camera to auto focus on Jupiter. This was about my only quick option, as the sky was dark by the time I was settuing up the DSLR. I did not bother attempting to focus any further.

A dew heater was used on the Schmidt Cassegrain only.

Wide field images were taken piggybacked on C11 while deep sky images were taken. Dark frames should have been used for the wide fields as the 10D is prone to hot pixels, at 5 min exposures. I failed to stop the f/1.4 lens down as many suggest to improve the performance of the optics.

Darks and flats were not used for QHY camera.

Nebulosity was used for imaging deep sky objects.
Autoguiding was with Push Here Dummy Autoguiding
DSLR capture was with ImagesPlus.


Milky Way Widefield

Widefields are Canon 10D camera with f/1.4 50mm fixed focal length lens. Focus was "auto focused" on Jupiter, then set to manual focus to hold focus.


The above image was 25minutes total exposure (5x5min at ISO 400) while imaging the Eagle Nebula (M16).


The above image was 25minutes total exposure (5x5min at ISO 400) while imaging the Lagoon Nebula (M8).

The artifact in the lower right is the horizon. I have noticed that in both images, inparticular the lower one, that the stars have noticble trails near the horizon, while there are no trails at higher alltitudes. I can not explain this.

Next time I will have to do darks as these images are peppered with many hot pixels pretending to be stars.

Note that even though these imges were stacked, I applied no translations, just simply let stacking happen.

This portion of the sky contains the constellation
Sagittarius and prominently contains a significant portion of the milky way. Indeed this portion of the milky way is densest as it looks towards the center of our galaxy.

Eagle Nebula (M16) and Pillars of Creation


Lagoon Nebula (M8)



Bubble Nebula (NGC 7635)

Geneal infos:

Field Details
Date/Location: Saturday Septemer 19, 2009, 9:00pm (Start) at Moose Creek Ontario
Instrument: QHY8, through Celestron SCT C11 w/o Focal Reduction
Filters: None
Mount: Celestron CGE
Focal Ratio: Imaging at f/10, guiding at f/4.3
Guiding: Auto through William Optics Megres 90mm w/ Meade DSI and f/6.3 FR
Conditions: Visually clear with moderate humidity
Weather: 9 deg. C
Exposure: 50 minutes total in 10 x 5 min exposures (Gain 0 Offset 65)
Focusing: Imaging with Stark Labs Nebulosity 2.0 (HFR >1.6 typical)
Image Capture: Imaging with Stark Labs Nebulosity 2.0
Autoguiding: Stark Labs PDH

Exposure Details and Processing
Stacking: Nebulosity 2, 10 of 10
Pixel Math: none
Levels/Stretch: Done in Images Plus
Binning: none

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