SBIG ST-6B CCD Images
From the Grove Creek Observatory

"Images of the universe on a Texas Instruments TC241 CCD Chip"

The Grove Creek Observatory has owned a ST-6B since 1997. The ST6-B CCD uses a Texas Instruments TC-241 CCD chip, which is 8.6 x 6.5mm in size, with 91,000 pixels in a 375 wide x 241 high pixel array. Each pixel measures 23 x 27 microns in size. Since these pixels are not square, we process the final image using the "pixel math" function to square our images to give the correct perspective. Large pixel sized CCD cameras, like the ST-6B are well suited to telescopes with focal lengths of 3,000mm or more.

We mainly use our ST-6B on our Vintage 1971 Celestron Pacific C-14 Schmidt Cassegrain Telescope at the Grove Creek Observatory. It has a focal length of 3,910mm (154") and an aperture of 36cm (14"). The ST-6B provides a field of view on the C-14 at f/11 of 7.6^min x 5.7^min and the resolution of each pixel is 1.3^seconds in the C-14's standard configuration. When using the C-14 with a focal reducer at f/7, it reduces the effective focal length to 2,488mm (98") and the field of view increases to 11.9^min x 8.9^min with a resolution of 2^sec/pixel. Recently, we have purchased an Optec MAXfield focal reducer, which gives a further reduction in focal length down to 1,327mm (52") at f/3.7 with the widest field possible of 16.8^min x 22.3^min with a resolution of 3.9^sec/pixel.

       
Saturn RGB                                      Jupiter RGB

NGC5139 - Omega Centauri Globular Cluster.
Our first image at f/3.7, using the Optec MAXfield focal reducer.
Single 60 second exposure, no processing except for pixel math
(squaring of the pixels) and dark frame reduction. Taken through the
 C-14 using the ST-6B CCD camera at -30 degrees C.
Image taken 10pm LT, 1st April, 2003.

IC 434 - The Horse Head Nebula in Orion.
Taken at f/3.7, using the Optec MAXfield focal reducer through the C-14,
 using the Track & Acclimate function of the ST-6B at -30 degrees C.
This is a stack of 30 x 30 second images using Track & Acclimate.
North at top, image taken at 9pm LT, 2nd April, 2003

NGC 4945 - 39^min long magnitude 9 galaxy in Centaurus.
 Taken at f/3.7, using the Optec MAXfield focal reducer through the C-14,
 using the Track & Acclimate function of the ST-6B at -40 degrees C.
This is a stack of 20, 30 second images. There is no way this galaxy would have
been able to fit in the field of our C-14, without the MAXfield telecompressor.
North at top, image taken at 2am LT, 2nd April, 2003.

MAXfield focal reducer from:

Optec Inc

NGC5236 (M83). A magnitude 8.1  barred spiral galaxy in Hydra.
Taken through the C-14 @f/7 using the ST-6B CCD camera
30 stacked exposures of 30 seconds each (15 mins) with the
camera using the Track & Acclimate function at -40 degrees C.
Image taken 29th March, 1998 at 11pm local time.

NGC3372 - Eta Carina Nebula
Taken through the C-14 @f/7 using the ST-6B CCD camera
30 stacked exposures of 30 seconds each (15 mins) with the
camera using the Track & Acclimate function at -35 degrees C.
Image taken 17th October, 2001.