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NGC253 Sculptor Galaxy, Silver Coin or Silver Dollar Galaxy

Object Information
NGC253 Sculptor Galaxy, Silver Coin or Silver Dollar Galaxy

• QSO analysis of NGC253 area
• Astronomy Picture of the Day
  • NGC 253: Dusty Island Universe
  • NGC 253 Close-Up
• Wikipedia
• SEDS
• NOAO The Sculptor Galaxy, NGC253

Full Scale Image	Full Scale Negative Image
Faint Galaxies and Stars Analysis The above three images are south at top and therefore are 180 degrees rotated in respect to the below references with images. The image to the right is north at top to match references below. The below faint galaxies are to the left of the red ticks in order from top to bottom in image to the right. Faint star 0645-0008796 is to the left of the blue tick. 2MASX J00482185-2507365 in NASA/IPAC Extragalactic database 2MASX J00474537-2508373 20.1 magnitude galaxy in NASA/IPAC Extragalactic database 2MASX J00472894-2526263 in NASA/IPAC Extragalactic database [B86c] 21 20.9 magnitude galaxy in SIMBAD database. This is the faintest galaxy I have image up to today. Below are the [B86c] 21 measurements on the calibrated image. Peak measurement = 394.85 Background measurement = 336.4 Signal to noise = 394.85/336.4 = 1.17 [CFC97] SC 30 in NASA/IPAC Extragalactic database Star 0645-0008796 from USNO B1.0 catalog at RA 00 47 24.5040, DEC -25 28 09.250 is 20.1 magnitude at USNO Flagstaff Station Integrated Image and Catalogue Archive Service
[B86c] 21 Galaxy Peak Measurement = 394.85	[B86c] 21 Galaxy Near Background Measurement = 336.4
Star 0645-0008796 from USNO B1.0 catalog Peak Measurement = 330.96	Star 0645-0008796 from USNO B1.0 catalog Background Measurement = 326.26

Image Information

• Field of view: 118 arcminutes wide x 77.1 arcminutes high
• Top image is half size
• North is bottom and west is left in the top three images
  
• Exposure: 61 images x 120 seconds per image (122 minutes total)
• CCD-TEMP: -30°C
• Astronomik Type IIc Luminance filter
• Guided

Observing Information

• OBS-Location: Oregon Star Party (OSP), OR USA
• DATE-Local = August 31, 2008
• TIME-Local of first image = 1:28 AM
• TIME-Local of last image = 3:54 AM
• NGC253 was low on the horzion starting at 16°43' altitude at 1:28 AM and rising to 19°41' at 3:54 AM

Imaging Equipment

• CCD camera: QSI 532ws-M1 (9.7mm x 14.9mm)
• Telescope: Tele Vue NP-101is APO refractor (4 inch dia., focal length = 540, f/5.4)
• Focal reducer: Tele Vue NPR-1073 0.8X (focal length = 432, f/4.3, 3.24 arcsec/pix)
• Telescope mount: Orion Telescopes and Binoculars Atlas EQ-G Mount with GoTo Controller
• Tripod: Losmandy G-11 tripod
• Guide camera: Orion Telescopes and Binoculars StarShoot AutoGuider
• Guide scope: 40mm dia., 250mm focal length
• Guiding software: Stark Labs PHD Guiding

Imaging Processing

• AIP4WIN V2.2
  • Series Analysis Tool Whole-Image Statistics on 64 darks, SeriesAnalysisQSI532Darks-30c20080420.txt
  • Series Analysis Tool Whole-Image Statistics on 61 images, SeriesAnalysisNGC253-20080831.txt
  
• Diffraction Limited MaxIm DL V5.02
  • Create master dark with SD Mask combine
  • Calibrate images with master dark
  • Create master dark with SD Mask
  • Create master calibrated image with stack, Auto - star matching and SD Mask combine
  • Information: Measure Signal to Noise of the background with no stars
    • Background average 321.026/background Std Dev 1.273 = Signal to Noise 252.18
  • Digital Development Auto with Kernal- User Filter to no sharpening
  • Curves to stretch image accross 16-bits
  • Local Adaptive Filter, Radius 3 and Contrast 2.5
  • Screen Stretch using Max Value: 0 to 66914
  • Save as FIT
  • Save as 16-bit TIFF for Photoshop, Stretch, Linear Only, Input Range Screen Stretch, Output Range 16-bit
• Adobe Photoshop CS3 10.0.1
  • Smart Sharpen
  • Reduce Noise
  • Crop stacking edge affects
  • Resize
  • Brighten image for JPG
  • Save as JPG for webpage

Monitor Test Pattern

The following test pattern is to help you adjust your monitor to best view the CCD astro images. The test pattern is used for adjusting monitor brightness, and contrast. Adjust monitor brightness and contrast to see all 16 gray scale levels. The most important adjustment when viewing astro images is to see the differences in all of the black bands.

© 1998-2008 David Haworth