Stephan's Quintet (NGC 7317, NGC 7318A, NGC 7318B, NGC 7319, NGC 7320)

Noirlab_noao-sq2_1024

noirlab_noao-sq2 June 30th, 2020

Credit: N.A.Sharp/NOIRLab/NSF/AURA

Stephan's Quintet, as its name implies, is a group of five galaxies (NGC7317, 7318A, 7318B, 7319 and 7320) in the constellation Pegasus. This unusual system has often been used as proof that the redshift is not truly a distance indicator, which would completely overturn current cosmology, because although four of the galaxies have similar, large redshifts, the fifth (NGC7320), although apparently a member of the group, shows a much smaller redshift. Conventional theory states that the low-redshift galaxy is in a nearby group (the NGC7331 group) and by coincidence appears on the sky projected against a distant background group. Opponents point to debris and tails around the low-redshift galaxy, suggesting that it is interacting with the high-redshift systems, which would require that all five galaxies be at the same physical location in space. Note that this picture includes a sixth nearby galaxy with similar redshift to the four high-redshift members of the group.he components are identified in this picture by their NGC number, with their redshift in kilometers per second given underneath each name. This picture was taken at the Kitt Peak National Observatory's 0.9-meter telescope in October of 1998 by Nigel Sharp. North is up, east is to the left.

Provider: NOIRLab

Image Source: https://noirlab.edu/public/images/noao-sq2/

Curator: NSF's NOIRLab, Tucson, AZ, USA

Image Use Policy: Creative Commons Attribution 4.0 International License

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Image Details

Image Type
Observation
Object Name
NGC 7317 NGC 7318A NGC 7318B NGC 7319 NGC 7320 Stephan's Quintet
Noirlab_noao-sq2_128
 

Position Details

Position (ICRS)
RA = 22h 35m 48.8s
DEC = 34° 1’ 38.9”
Orientation
North is 1.9° CCW
Field of View
9.1 x 9.1 arcminutes
Constellation
Pegasus
Noirlab_noao-sq2_1280
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ID
noao-sq2
Subject Category
Subject Name
NGC 7317, NGC 7318A, NGC 7318B, NGC 7319, NGC 7320, Stephan's Quintet
Credits
N.A.Sharp/NOIRLab/NSF/AURA
Release Date
2020-06-30T21:34:01
Lightyears
Redshift
Reference Url
https://noirlab.edu/public/images/noao-sq2/
Type
Observation
Image Quality
Distance Notes
Facility
Instrument
Color Assignment
Band
Bandpass
Central Wavelength
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
338.9531806, 34.02747663
Reference Dimension
1600.0, 1600.0
Reference Pixel
1287.975845, 1476.154722
Scale
-9.44e-05, 9.46e-05
Rotation
1.88320437
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
NSF's NOIRLab
URL
https://noirlab.edu
Name
Email
Telephone
Address
950 North Cherry Ave.
City
Tucson
State/Province
AZ
Postal Code
85719
Country
USA
Rights
Creative Commons Attribution 4.0 International License
Publisher
NSF's NOIRLab
Publisher ID
noirlab
Resource ID
noao-sq2
Metadata Date
2020-09-26T03:24:04.533486
Metadata Version
1.1
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Detailed color mapping information coming soon...

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There is no distance meta data in this image.