New Images with an FSQ106 and U8300 at the Blue Mountain Vista Observatory*
Dick Steinberg
April 11, 2010
We are currently experimenting with a new wide-field setup at the BMVO. An Alta U8300 camera and Takahashi FSQ106ED, graciously made available on loan by Frank Colosimo, are now mounted on the Paramount ME in shed 2 at the observatory.
The U8300 is based on a monochrome KAF-8300E chip with 3448x2574 pixels (8.9 megapixels) each 5.4 microns square. Coupled with the 525 mm focal length of the FSQ, the camera gives a scale of 2.12 arc sec/pixel and a field of view of 2.0 x 1.5 degrees, a bit smaller than the 2.5 x 1.7 degree field of the Orion StarShoot Pro used recently. The new system, however, gives nice round stars out to the extreme corners of the frame. In that regard, it is outperforming the formerly used Televue NP101/Orion SSPro combination. The new system also has significantly improved sensitivity due to the higher quantum efficiency of the chip and the lack of color filters. The limiting magnitude of the new system for a one-hour exposure is in the vicinity of 19.5, compared to about 18 for the old system. This is a fairly impressive number for a system based on a mere four-inch telescope.
The first image presented here from the new system is a 90-minute exposure of the M81-M82 system. It is interesting to compare this image with a similar one taken recently with the old NP101-based system.
An animation of the famous distorted spiral galaxy NGC3718 in Ursa Major compares an 85-minute exposure taken last night (April 10) with the new 4" system with a 2-year-old 60-minute exposure of the same object taken (from Narberth) with a 12" LX200 SCT and an ST8 camera. The sensitivity of the two instruments is not very different, but the enormously increased field of view is impressive. Note that the resolution of the 4" instrument is a bit lower mostly because of undersampling at 2 arcsec/pixel compared to the 1 arcsec/pixel scale of the 12" system.
On April 10, we also obtained
I. a 90-minute image of Hoag's ring galaxy , PGC54559 in Serpens. Look (with significant enlargement) near the center of the frame for this interesting object.
II. a 90-minute image of Keenan's system, NGC5216 in Ursa Major. Look for the bridge connecting the two galaxies near the center of the frame.
Dick
*Please note that these images are 3448x2574 pixels in size and require a magnification of at least 2 (4 preferred) to render maximum detail on a typical monitor. Firefox add-on Image Zoom is recommended.
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current setup:
Takahashi FSQ106ED @ f/5 FL 525mm -- Paramount ME -- Alta U8300 -- FLI-DF2 digital focuser controlled by FocusMax -- acquisition and processing with MaxIm DL v5 -- automation with CCD Commander v1.6 -- all images acquired remotely using Radmin v3.4 -- 5 min subs unguided -- 2.12 arcsec/pixel
