NGC 7331

Click on image for larger version.

NGC 7331 is one of 18 galaxies chosen by the HST Extragalactic Distance Scale Key Project to calibrate secondary distance estimators, using HST to obtain an accurate distance via Cepheid variables, with the ultimate goal of using these to measure H(naught, a cosomological parameter) to an external accuracy of 10%. It was determined this galaxy is 49 million light years away (and perhaps 30,000 light years across). In this image you will see some of the nearby neighbors being both spiral and elliptical galaxies. Nearby by this feild (not shown) is another famous group of galaxies known as Stephan's Quintet.


20in RC Optical Systems telescope Operating at f/8.4
Paramount ME Robotic Telescope Mount
SBIG ST10XME CCD camera with color filter wheel

L R G B color production was used to create this image.

Luminance = 90 minutes binned 1x1
Red = 30 minutes binned 2x2
Green = 30 minutes binned 2x2
Blue = 30 minutes binned 2x2

  • Two iterations of CCDsharp were applied to this image.
  • Digital Development (DDP) via Maxim/DL was also used in order to display the the very dim and very bright details of the image simultaneously.

  • Minimum credit line: Paul Mortfield and Dietmar Kupke/Flynn Haase/NOAO/AURA/NSF

    RETURN to the GALAXIES page.

    BACK to main Best of AOP page.

    Would you like to take images like this? Click here.

    [NOAO logo] Return to NOAO Home Page

    Updated: 06/27/03