Wednesday, May 15, 2013

M97 and M108

M97 and M108 by S Migol
M97 and M108, a photo by S Migol on Flickr.
Via Flickr:
M97 and M108 as seen on May 12 & 14, 2013. Taken at Montebello OSP on two nights. There was a third night that had bad data because of clouds and accidentally leaving the camera on ISO 400.

Standard setup: SV4 and cooled Pentax K10D DSLR. My first real use of the cold-finger modified camera outside of the back yard. Thermostat was set to -10C and the EXIF temps read 14-15C on the warmer night and 10C on the cooler night. I also added flocking material to the inside of the flattener to help control off-axis flare. This latter modification seems to help significantly.

Flats were generated using the LED panel but I'm considering that these are not really flat. I'll probably make a flat box repurposing the LED panel to give better and wider flats for consistency.

Getting much better results with flexure, too. I've been able to mostly fix the flexure, now I just have field rotation to control.

Image data is from 20 subs of 1200 seconds duration at 100 ISO. Guided and calibrated with Maxim. Stacked in DSS. Processed in PI.

Here's the plate solve:
Resolution ........ 1.909 arcsec/pix
Rotation .......... 91.658 deg
Focal ............. 655.81 mm
Pixel size ........ 6.07 um
Field of view ..... 1d 59' 44.1" x 1d 21' 27.4"
Image center ...... RA: 11 12 47.265 Dec: +55 21 17.86
Image bounds:
top-left ....... RA: 11 17 14.653 Dec: +54 19 58.40
top-right ...... RA: 11 17 53.471 Dec: +56 19 32.53
bottom-left .... RA: 11 07 55.809 Dec: +54 22 17.64
bottom-right ... RA: 11 08 05.781 Dec: +56 21 58.91