The lights of a galactic bar

Esahubble_potw2422a_1024

esahubble_potw2422a May 27th, 2024

Credit: ESA/Hubble & NASA, D. Thilker

This week, an image of the broad and sweeping spiral galaxy NGC 4731 is the Hubble Picture of the Week. This galaxy lies among the galaxies of the Virgo cluster, in the constellation Virgo, and is located 43 million light-years from Earth. This highly detailed image was created using six different filters. The abundance of colour illustrates the galaxy's billowing clouds of gas, dark dust bands, bright pink star-forming regions and, most obviously, the long, glowing bar with trailing arms. Barred spiral galaxies outnumber both regular spirals and elliptical galaxies put together, numbering around 60% of all galaxies. The visible bar structure is a result of orbits of stars and gas in the galaxy lining up, forming a dense region that individual stars move in and out of over time. This is the same process that maintains a galaxy's spiral arms, but it is somewhat more mysterious for bars: spiral galaxies seem to form bars in their centres as they mature, accounting for the large number of bars we see today, but can also lose them later on as the accumulated mass along the bar grows unstable. The orbital patterns and the gravitational interactions within a galaxy that sustain the bar also transport matter and energy into it, fuelling star formation. Indeed, the observing programme studying NGC 4731 seeks to investigate this flow of matter in galaxies. Beyond the bar, the spiral arms of NGC 4731 stretch out far past the confines of this close-in Hubble view. The galaxy’s elongated arms are thought to result from gravitational interactions with other, nearby galaxies in the Virgo cluster. [Image Description: A close-in view of a barred spiral galaxy. The bright, glowing bar crosses the centre of the galaxy, with spiral arms curving away from its ends and continuing out of view. It’s surrounded by bright patches of light where stars are forming, as well as dark lines of dust. The galaxy’s clouds of gas spread out from the arms and bar, giving way to a dark background with some foreground stars and small, distant galaxies.] Links Pan of NGC 4731 

Provider: Hubble Space Telescope | ESA

Image Source: https://esahubble.org/images/potw2422a/

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

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details Image Details

Image Type
Observation
Object Name
NGC 4731
Esahubble_potw2422a_128
 

Position Details Position Details

Position (ICRS)
RA = 12h 51m 1.1s
DEC = -6° 23’ 33.1”
Orientation
North is 55.7° CW
Field of View
2.6 x 2.7 arcminutes
Constellation
Virgo

Color Mapping Details Color Mapping

  Telescope Spectral Band Wavelength
Purple Hubble (WFC3) Ultraviolet (UV) 275.0 nm
Purple Hubble (WFC3) Optical (U) 336.0 nm
Blue Hubble (WFC3) Optical (B) 438.0 nm
Green Hubble (WFC3) Optical (V) 555.0 nm
Red Hubble (WFC3) Optical (I) 814.0 nm
Red Hubble (WFC3) Optical (H-alpha + NII) 657.0 nm
Spectrum_base
Purple
Purple
Blue
Green
Red
Red
Esahubble_potw2422a_1280
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ID
potw2422a
Subject Category
Subject Name
NGC 4731
Credits
ESA/Hubble & NASA, D. Thilker
Release Date
2024-05-27T06:00:00
Lightyears
Redshift
Reference Url
https://esahubble.org/images/potw2422a/
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, Purple, Blue, Green, Red, Red
Band
Ultraviolet, Optical, Optical, Optical, Optical, Optical
Bandpass
UV, U, B, V, I, H-alpha + NII
Central Wavelength
275, 336, 438, 555, 814, 657
Start Time
Integration Time
Dataset ID
None, None, None, None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
192.75455492776166, -6.39253707207148
Reference Dimension
3971.0, 4087.0
Reference Pixel
1985.5, 2043.5
Scale
-1.10114318942594e-05, 1.10114318942594e-05
Rotation
-55.720000000000084
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
potw2422a
Metadata Date
2024-05-26T23:58:16+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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