Small but significant

Esahubble_potw1732a_500

esahubble_potw1732a August 7th, 2017

Credit: ESA/Hubble & NASA

The subject of this NASA/ESA Hubble Space Telescope image is a dwarf galaxy named NGC 5949. Thanks to its proximity to Earth it sits at a distance of around 44 million light-years from us, placing it within the Milky Ways cosmic neighbourhood NGC 5949 is a perfect target for astronomers to study dwarf galaxies. With a mass of about a hundredth that of the Milky Way, NGC 5949 is a relatively bulky example of a dwarf galaxy. Its classification as a dwarf is due to its relatively small number of constituent stars, but the galaxys loosely-bound spiral arms also place it in the category of barred spirals. This structure is just visible in this image, which shows the galaxy as a bright yet ill-defined pinwheel. Despite its small proportions, NGC 5949s proximity has meant that its light can be picked up by fairly small telescopes, something that facilitated its discovery by the astronomer William Herschel in 1801. Astronomers have run into several cosmological quandaries when it comes to dwarf galaxies like NGC 5949. For example, the distribution of dark matter within dwarfs is quite puzzling (the cuspy halo problem), and our simulations of the Universe predict that there should be many more dwarf galaxies than we see around us (the missing satellites problem).

Image Source: https://www.spacetelescope.org/images/potw1732a/

Curator: ESA/Hubble, Garching bei München, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
NGC 5949
Subject - Local Universe
Galaxy » Type » Barred
Galaxy » Size » Dwarf
Esahubble_potw1732a_128
 

Position Details

Position (ICRS)
RA = 15h 28m 0.5s
DEC = 64° 45’ 47.1”
Orientation
North is 78.2° CW
Field of View
2.7 x 1.4 arcminutes
Constellation
Draco

Color Mapping

  Telescope Spectral Band Wavelength
Arrow_left_red Hubble Space Telescope (WFC3) Infrared (I) 814.0 nm
Arrow_left_green Hubble Space Telescope (WFC3) Optical (V) 555.0 nm
Arrow_left_blue Hubble Space Telescope (WFC3) Optical (B) 438.0 nm
Arrow_left_blue Hubble Space Telescope (WFC3) Ultraviolet (UV) 336.0 nm
Arrow_left_purple Hubble Space Telescope (WFC3) Ultraviolet (UV) 275.0 nm
Spectrum_base
Arrow_top_red
Arrow_top_green
Arrow_top_blue
Arrow_top_blue
Arrow_top_purple
Esahubble_potw1732a_1280
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ID
potw1732a
Subject Category
C.5.1.2   C.5.2.2  
Subject Name
NGC 5949
Credits
ESA/Hubble & NASA
Lightyears
Redshift
Reference Url
https://www.spacetelescope.org/images/potw1732a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
WFC3, WFC3, WFC3, WFC3, WFC3
Color Assignment
Red, Green, Blue, Blue, Purple
Band
Infrared, Optical, Optical, Ultraviolet, Ultraviolet
Bandpass
I, V, B, UV, UV
Central Wavelength
814, 555, 438, 336, 275
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
232.002053745, 64.7630757752
Reference Dimension
4060.0, 2117.0
Reference Pixel
2030.0, 1058.5
Scale
-1.10054427749e-05, 1.10054427749e-05
Rotation
-78.24
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
ESA/Hubble
URL
http://www.spacetelescope.org
Name
Email
Telephone
Address
Karl-Schwarzschild-Strasse 2
City
Garching bei München
State/Province
Postal Code
D-85748
Country
Germany
Rights
Creative Commons Attribution 4.0 International License
Publisher
ESA/Hubble
Publisher ID
esahubble
Resource ID
potw1732a
Metadata Date
2017-02-21T18:23:50+01:00
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.