Four Filter Fusion

Esahubble_potw2149a_1024

esahubble_potw2149a December 6th, 2021

Credit: ESA/Hubble & NASA, A. Riess et al.

This stellar whirlpool is a spiral galaxy named NCG 7329, which has been imaged by Hubble’s Wide Field Camera 3 (WFC3). Creating a colourful image such as this one using a telescope such as Hubble is not as straightforward as pointing and clicking a camera. Commercial cameras will typically try to collect as much light of all visible wavelengths as they can, in order to create the most vibrant images possible. In contrast, raw images collected by Hubble are always monochromatic, because astronomers typically want to capture very specific ranges of wavelengths of light at any time, in order to do the best, most accurate science possible. In order to control which wavelengths of light will be collected, Hubble’s cameras are equipped with a wide variety of filters, which only allow certain wavelengths of light to reach the cameras’ CCDs (a CCD is a camera’s light sensor — phone cameras also have CCDs!).  How are the colourful Hubble images possible given that the raw Hubble images are monochromatic? This is accomplished by combining multiple different observations of the same object, obtained using different filters. This image, for example, was processed from Hubble observations made using four different filters, each of which spans a different region of the light spectrum, from the ultraviolet to optical and infrared. Specialised image processors and artists can make informed judgements about which optical colours best correspond to each filter used. They can then colour the images taken using that filter accordingly. Finally, the images taken with different filters are stacked together, and voila! The colourful image of a distant galaxy is complete, with colours as representative of reality as possible.

Provider: Hubble Space Telescope | ESA

Image Source: https://esahubble.org/images/potw2149a/

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

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
NGC 7329
Subject - General
Galaxy > Type > Spiral
Esahubble_potw2149a_128
 

Position Details

Position (ICRS)
RA = 22h 40m 24.4s
DEC = -66° 28’ 47.5”
Orientation
North is 22.7° CCW
Field of View
2.4 x 2.3 arcminutes
Constellation
Tucana

Color Mapping

  Telescope Spectral Band Wavelength
Red Hubble (WFC3) Infrared (H) 1.6 µm
Orange Hubble (WFC3) Optical (I) 814.0 nm
Cyan Hubble (WFC3) Optical (V) 555.0 nm
Blue Hubble (WFC3) Optical (Long pass) 350.0 nm
Luminosity Hubble (WFC3) Optical (Long pass) 350.0 nm
Spectrum_base
Red
Orange
Cyan
Blue
Luminosity
Esahubble_potw2149a_1280
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ID
potw2149a
Subject Category
E.5.1.1  
Subject Name
NGC 7329
Credits
ESA/Hubble & NASA, A. Riess et al.
Release Date
2021-12-06T06:00:00
Lightyears
Redshift
Reference Url
https://esahubble.org/images/potw2149a/
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, Orange, Cyan, Blue, Luminosity
Band
Infrared, Optical, Optical, Optical, Optical
Bandpass
H, I, V, Long pass, Long pass
Central Wavelength
1600, 814, 555, 350, 350
Start Time
Integration Time
Dataset ID
None, None, None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
340.10162944477577, -66.47985458009909
Reference Dimension
3582.0, 3469.0
Reference Pixel
1791.0, 1734.5
Scale
-1.1008714674239002e-05, 1.1008714674239002e-05
Rotation
22.660000000000025
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
potw2149a
Metadata Date
2021-10-25T13:31:20+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.