NGC 7331, NGC 7335, NGC 7336, NGC 7337 & NGC 7340
The above image wah taken with 80-mm refractor with CB245 CCD camera (252 x 242 12-bit pixels).
The above image is a 4 x resampling enlargement of center of the
NGC 7331 image and rotated 90 degrees.
Compare this image's ability to detect faint objects that
are shown in the below DSS image. The FOV is 14.18' high by 25.15' wide.
Image was taken at home which is located 16.6 miles from the center of
Portland, Oregon, U.S.A.
Comparsion with the
STScI Digitized Sky Survey (DSS) image which was taken with a 48-inch Oschin Schmidt Telescope on Palomar Mountain.
Image photographed on 14-inch square glass plate and then digitized (14,000 x 14,000 15-bit pixels/plate)
NGC: New General Catalog
||Very Elongated Galaxy
||Very Elongated Galaxy
Located in constellation:
Right ascension in hours:minutes:
Declination in degrees:minutes:
Size: arc minutes
Date September 20, 1998
Time at end of first CCD image 22:41 PDT
Time at end of last CCD image 23:02 PDT
CCD image time: Six 240 seconds images added together
Sky transparency: 5.2 (Magnitude of the faintest star visible with the unaided eye in Ursa Minor)
Moon sets at 19:28 PDT on September 20, 1998
Astronomical twilight ends in the evening at 20:51 PDT on September 20, 1998
Astronomical twilight starts in morning at 5:11 PDT on September 21, 1998
- On the drive way at home
- City: Camas
- State: Washington
- Country: U.S.A.
- Longitude: 122 degrees 23.01 minutes
- Latitude: 45 degrees 40.09 minutes
- CCD observing telescope:
- Orion ShortTube 80 mm aperture refractor,
f/5 focal ratio, 400 mm focal length
- Filter used on CCD camera:
- Santa Barbara Instrument Group IR filter
- CCD camera:
- Richard Berry
CCD Cookbook CB245
built by David Haworth
- Telescope Finder:
schmidt-cassegrain 11" (279 mm) aperture,
f/6.3 focal ratio, 1764 mm focal length
(using Celestron f/6.3 focal reducer),
Tel Vue 35 mm Panoptic eye piece, magnification 50.4
- Telescope mount:
- Losmandy G-11
- Polar aligment:
- Used the Polar Axis Finderscope in the G-11 telescope mount
- CCD Camera Computer:
- Compaq LTE Lite/25 386
CB245 Camera Image Configuration
- CCD chip:
- Texas Instrument TC245
- CCD size:
- 252 horizontal x 242 vertical photosites
- 25.5 um-wide by 19.7 um-high
- Total CCD chip image size:
- 6.426 mm-wide by 4.7674 mm-high
- Photosite resolution with Orion telescope:
- 13.15" wide by 10.16" high
- Photosite width/hight aspect ratio:
- 1.294 to 1
- Image rotation:
- The acquired image is rotated 90 degrees to position the north edge of the image at the top of the Web page.
- Image resampling:
- Image resampled to
correct the aspect ratio of the nonsquare photosites to display square pixels.
Resampling creates a width/hight aspect ratio 1 to 1 with 187 horizontal x 252 vertical pixels.
- Image FOV:
- CCD image field of view (FOV) for the above images with the Orion telescope is 55.23' high by 40.98' wide
CB245 Camera Control Software Configuration
- CB245 control software: 245Plus by Richard Berry
- 245Plus image mode: external binning mode
- 245Plus gamma LUT: on
- 245Plus dark current reduction: off (no LDC modifications)
- 245Plus drift subtract: on
- 245Plus display: VGA mode
- 245Plus both delays: 10
Imaging Processing Software
- Image Calibration
Multi245 version 40d for
averaging 24 dark frames, registering multiple images, and stacking images to create a single calibrated image to be used for image processing.
No flat fields were taken.
- Image Processing
- Richard Berry's CB245 version 60a for using
Kunihiko Okano's Digital Development on
the calibrated image.
Software Bisque CCDSoft CCD Astronomy Software version 4.00.018 for brightness and
contrast adjustments, rotating image,
resampling to correct aspect ratio, and saving the image as a JPEG file for Web pages.
JASC Inc. Paint Shop Pro version 4.12 used for editing
star blooming in the image.
Use Test patterns to calibrate monitor brightness, contrast, height and width
© 1998-2003 David Haworth