Hubble Space Telescope picture of NGC 1097, a barred spiral galaxy that lies about 48 million light-years from Earth in the constellation Fornax. Credit: ESA/Hubble & & NASA, D. Sand, K. Sheth
This finely comprehensive image shows the heart of NGC 1097, a barred spiral galaxy that lies about 48 million light-years from Earth in the constellation Fornax. This photo exposes the complexity of the web of stars and dust at NGC 1097s center, with the long tendrils of dust selected in a dark red shade. The extent to which the galaxys structure is exposed is thanks to 2 instruments on the NASA/ESA Hubble Space Telescope: the Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS).
The idea that a single image can be taken utilizing 2 different electronic cameras is not extremely user-friendly. Nevertheless, it makes far more sense after delving into how lovely huge images like this one are composed. A helpful beginning point is to consider what color is, exactly. Our eyes can discover light waves at optical wavelengths between roughly 380 and 750 nanometres, using 3 types of receptors, each of which is sensitive to simply a slice of that variety. Our brain analyzes these particular wavelengths as colors. By contrast, a telescope camera like the WFC3 or ACS is sensitive to a single, broad series of wavelengths to make the most of the quantity of light gathered. Raw images from telescopes are always in greyscale, only revealing the quantity of the light recorded throughout all those wavelengths.
Colour images from telescopes are indirectly possible, nevertheless, with the help of filters. By moving a filter over the aperture of an instrument like the WFC3 or ACS, just light from a very particular wavelength range is let through– one such filter utilized in this image is for green light around 555 nanometres.
Raw images from telescopes are always in greyscale, only revealing the quantity of the light caught across all those wavelengths.
Colour images from telescopes are indirectly possible, nevertheless, with the aid of filters. By moving a filter over the aperture of an instrument like the WFC3 or ACS, just light from a very specific wavelength variety is let through– one such filter used in this image is for green light around 555 nanometres.
By ESA/Hubble
March 13, 2022
