Hubble Space Telescope image of spiral nebula NCG 7329, recorded with Wide Field Camera 3 (WFC3). Credit: ESA/Hubble & & NASA, A. Riess et al
. This stellar whirlpool is a spiral galaxy called NCG 7329, which has been imaged by Hubbles Wide Field Camera 3 (WFC3). Producing a colorful image such as this one using a telescope such as Hubble is not as uncomplicated as clicking a camera and pointing. Industrial video cameras will typically attempt to gather as much light of all noticeable wavelengths as they can, in order to produce the most dynamic images possible. In contrast, raw images collected by Hubble are constantly monochromatic, since astronomers typically wish to catch extremely particular series of wavelengths of light at any time, in order to do the very best, most precise science possible. In order to control which wavelengths of light will be gathered, Hubbles cameras are geared up with a wide range of filters, which just allow particular wavelengths of light to reach the cameras CCDs (a CCD is a cameras light sensor– phone electronic cameras also have CCDs!).
How are the vibrant Hubble images possible considered that the raw Hubble images are monochromatic? This is accomplished by integrating several various observations of the very same object, acquired using different filters. This image, for instance, was processed from Hubble observations made using four different filters, each of which covers a different area of the light spectrum, from the ultraviolet to infrared and optical. Specialized image processors and artists can make informed judgments about which optical colors best represent each filter used. They can then color the images taken using that filter accordingly. The images taken with various filters are stacked together, and voila! The vibrant image of a distant galaxy is complete, with colors as agent of reality as possible.
Hubble Space Telescope image of spiral galaxy NCG 7329, captured with Wide Field Camera 3 (WFC3). Creating a colorful image such as this one using a telescope such as Hubble is not as uncomplicated as pointing and clicking a video camera. How are the vibrant Hubble images possible given that the raw Hubble images are monochromatic?
By ESA/Hubble
December 6, 2021
