Primary and Secondary Mirrors Resilvered

I am pleased to report that the Alan Young Telescope at Cranbrook School, is now again in working condition.

Both mirrors of this large reflecting telescope, primary and secondary mirrors, have been re-silvered by Orion Optics.

Here is a photo by Graham Caller,

Mirrors Re-Installed In The Alan Young Telescope

Mirrors Re-Installed In The Alan Young Telescope

Photo taken just after the mirrors were reinstalled after their recoat by Orion Optics.

Bubble Nebula NGC7635

GCaller_bubble - OSH-1

Another fantastic astro image by CADSAS member Graham Caller.  this is NGC7635, the Bubble nebula in Cassiopeia.

He gathered data for this Oct 2016 to Jan 2017.  It’s a compilation of 35 single frames with exposure times of 5 minutes for Ha and 10 minutes for SII and OIII – total of 2 hr 55 mins of data capture.

OSH (OIII SII Ha) narrow band filters were used. He has colour mapped them to the RGB channels to give this false colour representation, in order to show a better contrast between the different channels.

OIII (oxygen) – red

SII (sulphur) – green

Ha (hydrogen) – blue

IC443 Image (the ‘Jellyfish’ nebula)

IC443 the Jellyfish Nebula by G Caller

Image of IC443 by Graham Caller

Another excellent image by our member Graham Caller. This time it’s IC443 also called the Jellyfish Nebula.  It’s a supernova remnant in the constellation of Gemini.

Click the thumbnail image above for a larger version, though note that this has been reduced in resolution for the web.  The original is even more impressive.

Graham comments:

Last week was IC443 week. A couple of clear nights and I grabbed 8 hours worth of 15mins subs. Topped up this week with another 2.5 hours to improve the signal to noise ratio further.
Resultant image stacked in PixInsight and processed.

Oh! this was taken using an Ha filter.

We are hoping Graham will give us a lecture in the future, on his astroimaging techniques.

Comet PANSTARRS Image 30th April

Comet Panstarrs captured 30th April by G Caller

Comet Panstarrs captured 30th April by G Caller

Image of comet PANSTARRS (C/2011 L4) captured by our member Graham Caller on 30th April 2013.

Graham comments:

I captured Panstarrs on 30th April as it was just above Cassiopeia. A tricky one to find.

This image comprises 6 x 6 min lights that have been stacked in DSS using the very useful ‘comet stacking’ option.

M51 Whirlpool Galaxy Image

M51 Whirlpool Galaxy Image by Graham Caller

M51 Whirlpool Galaxy by Graham Caller

Another lovely astroimage from member Graham Caller.  This is the interacting galaxies which make up M51, the “Whirlpool Galaxy” (as first listed by Charles Messier).

M51A and the smaller object M51B are interacting.  You can even see this galaxy combination with decent binoculars (but not quite as clearly as in this image!).

Graham comments:

“One M51 finished image attached.

Out of 18 images I got 10 usable that didn’t have noticable trailing. I suspect the defective shots were the result of periodic error in the mount tracking.

The 10 images stacked had flats and bias frames added but no darks as I haven’t taken 5 mins exposure darks before. That’s something to do on the cold and cloudy nights which we have no shortage of 🙂 “

M81 and M82 Image

M81 and M82 by GCaller
Image of M81 and M82 (above) captured by our member Graham Caller using a Canon Dslr.

Graham comments:

“Amazing what a bit of accurate polar alignment does for the shots. I’d been having trouble with star trails appearing after 60 sec exposures.
A bit of research later, lots of learning how to polar align accurately without plugging into a computer or mastering drift aligning and voila 150 secs exposures. (I should have pushed 180 but that’s another night)
It was cold and late when I finished but imagine what another hour of data could show. Good to see less noise with longer exposures. Attached also (below) is my first attempt on 2nd Feb.”

M81 M82 - earlier attempt by Graham Caller

M101 Pinwheel Galaxy Image

M101 Pinwheel Galaxy by Graham Caller

M101 Pinwheel Galaxy by Graham Caller (stacked final)

M101 Pinwheel Galaxy (single unstacked image)

M101 Pinwheel Galaxy (single unstacked image)

Image of the Pinwheel Galaxy M101, by our member Graham Caller.

The two images above (the finished final stacked image together with a single unstacked sub-image), clearly demonstrate the power of stacking many images of the same object. Deep Sky Stacker software was used.

Graham comments:
The fruits of my labour over the last two evenings.
3.5 hours of photos with the best 3 hours stacked and processed.

M101 is 21 million light years from us. For perspective, Andromeda is 2.5 million light years away.

This was a tricky target as I couldn’t see it through the telescope and only just in a 1 mins exposure.

See attached example of a single frame and the finished stacked image. Perhaps display these side by side to demonstrate what can be achieved by stacking.

Miky Way Image

Milky Way with Albireo and Dumbell Nebula highlighted

The Milky Way shot by Graham Caller on a very clear night in Sept.

Albireo is the bright star by the red arrow. The Dumbbell Nebula is to the left of the yellow arrow.

This is a combination of 90 x 10 secs exposures, 30 lights and a variety of darks, flat, and bias frames, stacked and processed using Deep Sky Stacker software.


North American Nebula, Deneb and Sadr

GCaller Swan Deneb Sadr North American Nebula

Image captured by Graham Caller of the area in Cygnus, showing the North American nebula (NGC7000).

The nebula is between the brightest star in the shot (Deneb) and the brightest ‘orange’ star at the 7 o’clock position from Deneb. It looks like a reddish fuzzy blur shaped like North America.

Composed from:
26 x 10 sec subs on an f1.8 50mm lens. ISO1600
Raw format, stacked in DSS