Smoke without fire: a different view of the cigar galaxy

Esahubble_potw1201a_1024

esahubble_potw1201a January 2nd, 2012

Credit: ESA/Hubble & NASA

This image shows the most detailed view ever of the core of Messier 82 (M 82), also known as the Cigar Galaxy. Rich with dust, young stars and glowing gas, M 82 is both unusually bright and relatively close to Earth. The starburst galaxy is located around 12 million light-years away in the constellation of Ursa Major (The Great Bear). This is not the first time Hubble has imaged the Cigar Galaxy. Previous images (for example heic0604) show a galaxy ablaze with stars. Yet this image looks quite unlike them, and is dominated instead by glowing gas and dust, with the stars almost invisible. Why such a difference? The new image is more detailed than previous Hubble observations in fact, it is the most detailed image ever made of this galaxy. But the reason it looks so dramatically different is down to the choices astronomers make when designing their observations. Hubbles cameras do not see in colour: they are sensitive to a broad range of wavelengths which they image only in greyscale. Colour pictures can be constructed by passing the light through different coloured filters and combining the resulting images, but the choice of filters makes a big difference to the end result. Using filters which allow through relatively broad bands of colours, similar to those our eyes see, results in natural-looking colours and bright stars, as starlight shines brightly across the spectrum. Using filters transparent only to the wavelengths emitted by specific chemical elements, as in this image, isolates the light from glowing gas clouds, while blocking out much of the starlight. This explains why the stars appear faint in this image, and why the dust lanes are sharply silhouetted against the brightly glowing gas clouds. The image shows the light emitted by sulphur (shown in red), visible and ultraviolet light from oxygen (shown green and blue, respectively), and light from hydrogen (cyan). The field of view is approximately 2.7 by 2.7 arcminutes.

Provider: Hubble Space Telescope | ESA

Image Source: https://www.spacetelescope.org/images/potw1201a/

Curator: ESA/Hubble, Garching bei München, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
Cigar Galaxy M82 M 82 Messier 82
Subject - Local Universe
Galaxy > Activity > Starburst
Esahubble_potw1201a_128
 

Position Details

Position (ICRS)
RA = 9h 55m 52.3s
DEC = 69° 40’ 39.1”
Orientation
North is 154.3° CW
Field of View
2.7 x 2.7 arcminutes
Constellation
Ursa Major

Color Mapping

  Telescope Spectral Band Wavelength
Red Hubble (WFC3) Optical (SII) 673.0 nm
Green Hubble (WFC3) Optical (OIII) 502.0 nm
Cyan Hubble (WFC3) Optical (H-beta) 487.0 nm
Blue Hubble (WFC3) Ultraviolet (OII) 373.0 nm
Spectrum_base
Red
Green
Cyan
Blue
Esahubble_potw1201a_1280
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ID
potw1201a
Subject Category
C.5.3.3  
Subject Name
Cigar Galaxy, M82, M 82, Messier 82
Credits
ESA/Hubble & NASA
Release Date
2012-01-02T10:00:00
Lightyears
Redshift
Reference Url
https://www.spacetelescope.org/images/potw1201a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
WFC3, WFC3, WFC3, WFC3
Color Assignment
Red, Green, Cyan, Blue
Band
Optical, Optical, Optical, Ultraviolet
Bandpass
SII, OIII, H-beta, OII
Central Wavelength
673, 502, 487, 373
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
148.967928141, 69.6775335759
Reference Dimension
4097.0, 4022.0
Reference Pixel
2048.0, 2011.0
Scale
-1.1009202736e-05, 1.1009202736e-05
Rotation
-154.28000000000011
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
potw1201a
Metadata Date
2011-09-19T12:00:43+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.