Solar Collage of Wavelengths
This collage of solar images from NASA's Solar Dynamics Observatory (SDO) shows how observations of the sun in different wavelengths helps highlight different aspects of the sun's surface and atmosphere. The collage also includes images from other SDO instruments that display magnetic and Doppler information.
From the sun's surface on out, the wavelengths SDO observes, measured in Angstroms, are:
- 4500: White light continuum, shows the sun's surface or photosphere
- 1700: Ultraviolet light continuum, shows surface of the sun. As well as a layer of the sun's atmosphere called the chromosphere, which lies just above the photosphere and is where the temperature begins rising.
- 1600: Emitted by carbon-4 (C IV) at around 10,000 Kelvin. C IV at these temperatures is present in the upper photosphere and what's called the transition region, a region between the chromosphere and the upper most layer of the sun's atmosphere called the corona. The transition region is where the temperature rapidly rises. SDO images of this wavelength are typically colorized in dark yellow.
- 304: Emitted by helium-2 (He II) at around 50,000 Kelvin. This light is emitted from the chromosphere and transition region. SDO images of this wavelength are typically colorized in red.
- 171: Emitted by iron-9 (Fe IX) at around 600,000 Kelvin. This wavelength shows the quiet corona and coronal loops, and is typically colorized in gold.
- 193: Emitted by iron-12 (Fe XII) at 1,000,000 Kelvin and iron 24 (Fe XXIV) at 20,000,000 Kelvin. The former represents a slightly hotter region of the corona and the later represents the much hotter material of a solar flare. This wavelength is typically colorized in yellow.
- 211: Emitted by iron-14 (Fe XIV) at temperatures of 2,000,000 Kelvin. These images show hotter, magnetically active regions in the sun's corona and are typically colorized in purple.
- 335: Emitted by iron-16 (Fe XVI) at temperatures of 2,500,000 Kelvin. These images also show hotter, magnetically active regions in the corona, and are typically colorized in blue.
- 94: Emitted by iron-18 (Fe XVIII) at temperatures of 6,000,000 Kelvin. Temperatures like this represent regions of the corona during a solar flare. The images are typically colorized in green.
- 131: Emitted by iron-20 (Fe XX) and iron-23 (Fe XXIII) at temperatures greater than 10,000,000 Kelvin, representing the material in flares. The images are typically colorized in teal.
Credit: NASA/SDO/GSFC › Link to associated news item