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  2. Fraunhofer lines - Wikipedia

    en.wikipedia.org/wiki/Fraunhofer_lines

    Solar spectrum with Fraunhofer lines as it appears visually. In 1802, English chemist William Hyde Wollaston [2] was the first person to note the appearance of a number of dark features in the solar spectrum. [3] In 1814, Joseph von Fraunhofer independently rediscovered the lines and began to systematically study and measure their wavelengths ...

  3. Sunlight - Wikipedia

    en.wikipedia.org/wiki/Sunlight

    Although the solar corona is a source of extreme ultraviolet and X-ray radiation, these rays make up only a very small amount of the power output of the Sun (see spectrum at right). The spectrum of nearly all solar electromagnetic radiation striking the Earth's atmosphere spans a range of 100 nm to about 1 mm (1,000,000 nm).

  4. Diffuse sky radiation - Wikipedia

    en.wikipedia.org/wiki/Diffuse_sky_radiation

    The blue sky spectrum contains light at all visible wavelengths with a broad maximum around 450–485 nm, the wavelengths of the color blue. Diffuse sky radiation is solar radiation reaching the Earth 's surface after having been scattered from the direct solar beam by molecules or particulates in the atmosphere .

  5. Visible spectrum - Wikipedia

    en.wikipedia.org/wiki/Visible_spectrum

    The visible spectrum is defined as that visible to humans, but the variance between species is large. Not only can cone opsins be spectrally shifted to alter the visible range, but vertebrates with 4 cones (tetrachromatic) or 2 cones (dichromatic) relative to humans' 3 (trichromatic) will also tend to have a wider or narrower visible spectrum ...

  6. Optical window - Wikipedia

    en.wikipedia.org/wiki/Optical_window

    The window runs from around 300 nanometers (ultraviolet-B) up into the range the human eye can detect, roughly 400–700 nm and continues up to approximately 2 μm. [1] [2] Sunlight mostly reaches the ground through the optical atmospheric window; [3] [4] the Sun is particularly active in most of this range (44% of the radiation emitted by the ...

  7. File:Solar spectrum en.svg - Wikipedia

    en.wikipedia.org/wiki/File:Solar_spectrum_en.svg

    English: This figure shows the solar radiation spectrum for direct light at both the top of the Earth's atmosphere (represented by the area in yellow) and at sea level (area in red). The sun produces light with a distribution similar to what would be expected from a 5525 K (5250 ° C ) blackbody , which is approximately the sun's surface ...

  8. Spectral line - Wikipedia

    en.wikipedia.org/wiki/Spectral_line

    Here, Fraunhofer lines in sunlight and Rayleigh scattering of this sunlight is the "source." This is the spectrum of a blue sky somewhat close to the horizon, looking east with the sun to the west at around 3–4 pm on a clear day. A spectral line is a weaker or stronger region in an otherwise uniform and continuous spectrum.

  9. Visible-light astronomy - Wikipedia

    en.wikipedia.org/wiki/Visible-light_astronomy

    A diagram of the electromagnetic spectrum with the Earth's atmospheric transmittance (or opacity) and the types of telescopes used to image parts of the spectrum.. Visible-light astronomy encompasses a wide variety of astronomical observation via telescopes that are sensitive in the range of visible light (optical telescopes).