The Milky Way’s Unusual Twin in Pegasus

Noirlab_iotw2451a_1024

noirlab_iotw2451a December 18th, 2024

Credit: International Gemini Observatory/NOIRLab/NSF/AURAImage Processing: J. Miller (International Gemini Observatory/NSF NOIRLab), M. Rodriguez (International Gemini Observatory/NSF NOIRLab) & M. Zamani (NSF NOIRLab)

The magnificent spiral galaxy NGC 7331, located approximately 40 million light-years away in the constellation Pegasus, is the brightest and closest galaxy in the visual galaxy group that bears its name, the NGC 7331 Group. Revealed in the details of this image are populations of hot stars and dark dust lanes winding throughout the spiral arms. Also known as Caldwell 30, this galaxy is often thought of as a twin to the Milky Way owing to its similar size and spiral structure. However, there are a couple of features of its core that set it apart from our home galaxy. For instance, astronomers have found evidence that the Milky Way has a central bar of stars and dust cutting through its center, a feature common to many spiral galaxies. But NGC 7331 lacks this feature. Additionally, NGC 7331’s central bulge rotates in the opposite direction to its galactic disk — unusual behavior compared to other galaxies and different from what we observe in the Milky Way. This image was taken by Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. You can find other views of NGC 7331 captured at Kitt Peak National Observatory, a Program of NSF NOIRLab, in 2014 and 1975 in the NOIRLab Image archive.

Provider: NOIRLab

Image Source: https://noirlab.edu/public/images/iotw2451a/

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

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details Image Details

Image Type
Observation
Object Name
NGC 7331
Noirlab_iotw2451a_128
 

Position Details Position Details

Position (ICRS)
RA = 22h 37m 3.7s
DEC = 34° 25’ 11.1”
Orientation
North is 90.0° CW
Field of View
5.6 x 4.2 arcminutes
Constellation
Pegasus

Color Mapping Details Color Mapping

  Telescope Spectral Band Wavelength
Blue Gemini-N (GMOS-N) Optical (g) 475.0 nm
Green Gemini-N (GMOS-N) Optical (r) 630.0 nm
Red Gemini-N (GMOS-N) Optical (i) 780.0 nm
Spectrum_base
Blue
Green
Red
Noirlab_iotw2451a_1280
×
ID
iotw2451a
Subject Category
Subject Name
NGC 7331
Credits
International Gemini Observatory/NOIRLab/NSF/AURAImage Processing: J. Miller (International Gemini Observatory/NSF NOIRLab), M. Rodriguez (International Gemini Observatory/NSF NOIRLab) & M. Zamani (NSF NOIRLab)
Release Date
2024-12-18T12:00:00
Lightyears
Redshift
Reference Url
https://noirlab.edu/public/images/iotw2451a/
Type
Observation
Image Quality
Distance Notes
Facility
Gemini North, Gemini North, Gemini North
Instrument
GMOS-N, GMOS-N, GMOS-N
Color Assignment
Blue, Green, Red
Band
Optical, Optical, Optical
Bandpass
g, r, i
Central Wavelength
475, 630, 780
Start Time
Integration Time
Dataset ID
None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
339.2654404775004, 34.419736572127825
Reference Dimension
2081.0, 1541.0
Reference Pixel
1040.5, 770.5
Scale
-4.4897421808702354e-05, 4.4897421808702354e-05
Rotation
-90.019999999999769
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
iotw2451a
Metadata Date
2024-10-23T23:10:13+02:00
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.

 

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