Tuesday, February 12, 2013

Witch Head Nebula (DRAFT)

Witch Head Nebula (DRAFT) by S Migol
Witch Head Nebula (DRAFT), a photo by S Migol on Flickr.
Via Flickr:
A work in progress, this is the Witch Head Nebula (IC 2118) near Rigel. Seen over two nights of data collection at Montebello OSP.

I'm trying some different ways of gathering data to see what I can do. These are 20 minute subs at 100 ISO. 24 subs made up this stack for about 8 hours of integration.

Still calibrating with Maxim and stacking with DSS before going to PI.

What I've found is that for the setup, the temperature range doesn't seem to matter as much any more. Using a "set point" for the cooler at 0C seems to give a flat response for noise across the session. Thus, there's not as much need to keep as large of a library of darks. This is a good thing. Also the texture of the noise changed, so I'll have to figure out new settings in Atrous wavelet processing.

There are still flexure issues with the camera. I think I know where the problem is. I'll try a fix tomorrow and test it out this weekend.

Here is the plate solve from PI:
Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]):
+0.000028253472 -0.000530158975 +0.507957495766
+0.000530163848 +0.000028685662 -0.939069255758
+0.000000000000 +0.000000000000 +1.000000000000
Resolution ........ 1.911 arcsec/pix
Rotation .......... 93.073 deg
Focal ............. 655.06 mm
Pixel size ........ 6.07 um
Field of view ..... 1d 49' 14.0" x 1d 6' 51.9"
Image center ...... RA: 05 05 55.880 Dec: -06 47 38.51
Image bounds:
top-left ....... RA: 05 07 58.890 Dec: -07 43 57.76
top-right ...... RA: 05 08 21.797 Dec: -05 54 53.67
bottom-left .... RA: 05 03 29.430 Dec: -07 40 20.61
bottom-right ... RA: 05 03 53.350 Dec: -05 51 17.32