‘S’ is for ‘Spiral’, ‘AB’ is for … ‘Weakly Barred’

Esahubble_potw2342a_1024

esahubble_potw2342a October 16th, 2023

Credit: ESA/Hubble & NASA, R. Chandar, J. Lee and the PHANGS-HST team

This glittering image shows the spiral galaxy IC 5332, which lies about 30 million light-years away in the constellation Sculptor, and has an almost face-on orientation to Earth. To explain what is meant by ‘face-on’, it is helpful to visualise a spiral galaxy as an (extremely) large disc. If the galaxy is oriented so that it appears circular and disc-shaped from our perspective here on Earth, then we can say that it is ‘face-on’. In contrast, if it is oriented so that it appears squashed and oval-shaped, then we would say that it is ‘edge-on’. The key thing is that the same galaxy would look extremely different from our perspective depending on whether it was face-on or edge-on as seen from Earth. Check out these previous Hubble Pictures of the Week for examples of another face-on spiral galaxy and an almost edge-on spiral galaxy.  IC 5332 is designated as an SABc-type galaxy in the De Vaucouleurs system of galaxy classification. The ‘S’ is straightforward, identifying it as a spiral galaxy, which it clearly is, given the well-defined arms of bright stars and darker dust that curl outwards from the galaxy’s dense and bright core. The ‘AB’ is a little more complex. It means that the galaxy is weakly barred, which refers to the shape of the galaxy’s centre. The majority of spiral galaxies do not spiral out from a single point, but rather from an elongated bar-type structure. SAB galaxies — which are also known as intermediate spiral galaxies — do not have a clear bar-shape at their core, but also do not spiral out from a single point, instead falling somewhere in between. The lowercase ‘c’ describes how tightly wound the spiral arms are: ‘a’ would indicate very tightly wound, and ‘d’ very loosely wound. Thus, IC 5332 is quite an intermediate spiral galaxy on many fronts: weakly barred, with quite loosely wound arms, and almost completely face-on! [Image Description: A close-in view of a spiral galaxy. It is seen face-on, showing its circular shape and tightly winding spiral arms. The galaxy glows brightly in the centre and dims to cool colours towards the edge. Dark, faint filaments of dust and brightly glowing, pink and orange bubbles of star formation mark the face of the galaxy.] Links Pan: ‘S’ is for ‘Spiral’, ‘AB’ is for … ‘Weakly Barred’

Provider: Hubble Space Telescope | ESA

Image Source: https://esahubble.org/images/potw2342a/

Curator: ESA/Hubble, Baltimore, MD, United States

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
IC 5332
Esahubble_potw2342a_128
 

Position Details

Position (ICRS)
RA = 23h 34m 26.5s
DEC = -36° 6’ 0.2”
Orientation
North is 35.3° CCW
Field of View
2.7 x 2.6 arcminutes
Constellation
Sculptor

Color Mapping

  Telescope Spectral Band Wavelength
Purple Hubble (WFC3) Ultraviolet (UV) 275.0 nm
Blue Hubble (WFC3) Optical (U) 336.0 nm
Cyan Hubble (WFC3) Optical (B) 438.0 nm
Green Hubble (WFC3) Optical (V) 555.0 nm
Orange Hubble (WFC3) Optical (I) 814.0 nm
Red Hubble (WFC3) Optical (N II) 658.0 nm
Spectrum_base
Purple
Blue
Cyan
Green
Orange
Red
Esahubble_potw2342a_1280
×
ID
potw2342a
Subject Category
Subject Name
IC 5332
Credits
ESA/Hubble & NASA, R. Chandar, J. Lee and the PHANGS-HST team
Release Date
2023-10-16T06:00:00
Lightyears
Redshift
Reference Url
https://esahubble.org/images/potw2342a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
WFC3, WFC3, WFC3, WFC3, WFC3, WFC3
Color Assignment
Purple, Blue, Cyan, Green, Orange, Red
Band
Ultraviolet, Optical, Optical, Optical, Optical, Optical
Bandpass
UV, U, B, V, I, N II
Central Wavelength
275, 336, 438, 555, 814, 658
Start Time
Integration Time
Dataset ID
None, None, None, None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
353.61057223568434, -36.1000524305834
Reference Dimension
4067.0, 3987.0
Reference Pixel
2033.5, 1993.5
Scale
-1.1020580113553126e-05, 1.1020580113553126e-05
Rotation
35.299999999999763
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
ESA/Hubble
URL
https://esahubble.org
Name
Email
Telephone
Address
ESA Office, Space Telescope Science Institute, 3700 San Martin Dr
City
Baltimore
State/Province
MD
Postal Code
21218
Country
United States
Rights
Creative Commons Attribution 4.0 International License
Publisher
ESA/Hubble
Publisher ID
esahubble
Resource ID
potw2342a
Metadata Date
2023-09-28T12:45:41+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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