M33 (Sept 2009)

This is M33 after a long time of processing. You can see more about this galaxy on Wikipedia.

 

The original lights came from the evenings of September 18 and the night of September 23-24, 2009

 

Taken with my Pentax K10D camera with the Stellarvue SV4 scope, operating at Prime Focus. A field flattenter was also used as well as a Baader Moon and Skyglow light pollution filter. Tracking was done with the Orion Starshoot Autoguider using a Stellarvue SV 70 ED. The DLSR in-camera noise reduction was turned off. Most shots were done with using the Pentax remote control software to do bulb interval shots. I allowed about 2 minutes of time between shots to give the camera a chance to cool off and for the batteries to recover.

 

Most of the darks were recorded well after the lights in an effort to help understand and control the noise that is generated by this camera. I learned that I had to be vigilant regarding IR light getting into the camera when making this library of darks. Also, it appears that the telescope body itself seems to act as a heatsink for this camera, making collecting darks requiring connecting the camera as if it was in the field.

 

Stacking was with DSS using the below settings:

 

Stacking mode: Custom Rectangle

Drizzle x2 enabled

 

Total exposure: 4hrs 42 mins 21s

 

Stacking step 1 ->2 frames (ISO: 800) - total exposure: 16 mn 4 s

-> Offset: 36 frames (ISO: 800) exposure: 1/4000 s

-> Dark: 40 frames (ISO : 800) exposure: 8 mn 3 s

-> Dark Flat: 36 frames (ISO : 800) exposure: 1/4000 s

-> Flat: 24 frames (ISO: 800) exposure: 1/4000 s

 

Stacking step 2 ->2 frames (ISO: 800) - total exposure: 20 mn 6 s

-> Offset: 36 frames (ISO: 800) exposure: 1/4000 s

-> Dark: 90 frames (ISO : 800) exposure: 10 mn 5 s

-> Dark Flat: 36 frames (ISO : 800) exposure: 1/4000 s

-> Flat: 24 frames (ISO: 800) exposure: 1/4000 s

 

Stacking step 3 ->4 frames (ISO: 400) - total exposure: 1 hr 0 mn 20 s

-> Offset: 24 frames (ISO: 400) exposure: 1/4000 s

-> Dark: 18 frames (ISO : 400) exposure: 15 mn 7 s

-> Dark Flat: 48 frames (ISO : 400) exposure: 1/1600 s

-> Flat: 19 frames (ISO: 400) exposure: 1/1600 s

 

Stacking step 4 ->1 frames (ISO: 400) - total exposure: 20 mn 7 s

-> Offset: 24 frames (ISO: 400) exposure: 1/4000 s

-> Dark: 3 frames (ISO : 400) exposure: 20 mn 9 s

-> Dark Flat: 48 frames (ISO : 400) exposure: 1/1600 s

-> Flat: 19 frames (ISO: 400) exposure: 1/1600 s

 

Stacking step 5 ->11 frames (ISO: 400) - total exposure: 2 hr 45 mn 44 s

-> Offset: 24 frames (ISO: 400) exposure: 1/4000 s

-> Dark: 11 frames (ISO : 400) exposure: 15 mn 4 s

-> Flat: 19 frames (ISO: 400) exposure: 1/1600 s

 

Processing was with PixInsight LE 1.0 using the instructions provided by Rogelio Andreo regarding gradient subtraction:

blog.deepskycolors.com/archivo/2010/05/

 

Further processing was done via the tutorial at this page from David Nash's website:

www.davesastro.co.uk/techniques/pixinsight_tutorial/index...

 

I'm extremely happy with how this image turned out. I know that there are a few gradients still showing up. Still, this is much better than I've been able to get from what I've always known was good data. The missing bits were getting a library of decent darks and flats and bias frames to give DSS some meat to chew on.

 

Finally being able to follow what is happening in PixInsight really helps as well.

 

Now I'll try to fill in the holes in my other data from last year and I'll see what I can get!

Done