Home to a hypergiant

Esahubble_potw1710a_500

esahubble_potw1710a March 6th, 2017

Credit: ESA/Hubble & NASA

Light travels through space at just under 300 000 kilometres per second! This staggering speed is used to calculate astronomical distances; although often misinterpreted as a unit of time (due to its misleading name), a light-year is actually a unit of astronomical distance, and is defined as the distance that light travels in a year. For reference, this is around nine trillion kilometres but its a little tricky to visualise! With this in mind, 15 000 light-years may sound like a truly huge distance, but compared to the vastness of the cosmos, its really quite nearby. In fact, an object sitting 15 000 light-years away would not even be outside our home galaxy, the Milky Way. This is roughly the distance between us and a young super star cluster known as Westerlund 1, home to one of the largest stars ever discovered. Stars are classified according to their spectral type, surface temperature, and luminosity. While studying and classifying the clusters constituent stars, astronomers discovered that Westerlund 1 is home to one of the largest stars ever discovered, originally named Westerlund 1-26. It is a red supergiant (although sometimes classified as a hypergiant) with a radius over 1500 times that of our Sun. If Westerlund 1-26 were placed where our Sun is in our Solar System, it would extend out beyond the orbit of Jupiter. Most of Westerlund 1s stars are thought to have formed in the same burst of activity, meaning that they have similar ages and compositions. The cluster is relatively young in astronomical terms at around three million years old it is a baby compared to our own Sun, which is some 4.6 billion years old.

Image Source: https://www.spacetelescope.org/images/potw1710a/

Curator: ESA/Hubble, Garching bei München, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
Westerlund 1
Subject - Milky Way
Star » Grouping » Cluster
Esahubble_potw1710a_128
 

Position Details

Position (ICRS)
RA = 23h 19m 12.6s
DEC = 17° 11’ 33.1”
Orientation
North is up
Field of View
0.9 x 0.8 arcminutes
Constellation
Pegasus

Color Mapping

  Telescope Spectral Band Wavelength
Arrow_left_blue Hubble Space Telescope (WFC3) Infrared (J) 1.3 µm
Arrow_left_green Hubble Space Telescope (WFC3) Optical (Water-CH4) 1.4 µm
Arrow_left_red Hubble Space Telescope (WFC3) Infrared (H) 1.6 µm
Spectrum_base
Arrow_top_blue
Arrow_top_green
Arrow_top_red
Esahubble_potw1710a_1280
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ID
potw1710a
Subject Category
B.3.6.4  
Subject Name
Westerlund 1
Credits
ESA/Hubble & NASA
Lightyears
Redshift
Reference Url
https://www.spacetelescope.org/images/potw1710a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
WFC3, WFC3, WFC3
Color Assignment
Blue, Green, Red
Band
Infrared, Optical, Infrared
Bandpass
J, Water-CH4, H
Central Wavelength
1250, 1390, 1600
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
349.802559549, 17.1925195327
Reference Dimension
2748.0, 2617.0
Reference Pixel
498.0, 498.5
Scale
-5.3779326086630433E-06, 5.3779326086630433E-06
Rotation
-0
Coordinate System Projection:
TAN
Quality
Position
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
potw1710a
Metadata Date
2016-10-28T10:28:07+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.