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  2. Sky brightness - Wikipedia

    en.wikipedia.org/wiki/Sky_brightness

    Sky brightness refers to the visual perception of the sky and how it scatters and diffuses light. The fact that the sky is not completely dark at night is easily visible. If light sources (e.g. the Moon and light pollution ) were removed from the night sky , only direct starlight would be visible.

  3. List of brightest stars - Wikipedia

    en.wikipedia.org/wiki/List_of_brightest_stars

    Most stars on this list appear bright from Earth because they are nearby, not because they are intrinsically luminous. For a list which compensates for the distances, converting the apparent magnitude to the absolute magnitude, see the list of most luminous stars. Some major asterisms, which feature many of the brightest stars in the night sky

  4. Apparent magnitude - Wikipedia

    en.wikipedia.org/wiki/Apparent_magnitude

    Combined magnitude (3rd brightest star in night sky) −0.04: star Arcturus: seen from Earth 4th brightest star to the naked eye [47] −0.01: star Alpha Centauri A: seen from Earth 4th brightest individual star visible telescopically in the night sky +0.03: star Vega: seen from Earth originally chosen as a definition of the zero point [48] +0. ...

  5. List of brightest natural objects in the sky - Wikipedia

    en.wikipedia.org/wiki/List_of_brightest_natural...

    This list contains natural objects up to apparent magnitude 3.5. All objects are listed by their visual magnitudes, and objects too close together to be distinguished are listed jointly.

  6. Orders of magnitude (illuminance) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude...

    Starlight overcast moonless night sky [1] 140 microlux: Venus at brightest [1] 200 microlux: Starlight clear moonless night sky excluding airglow [1] 10 −3: 1 millilux: 2 millilux: Starlight clear moonless night sky including airglow [1] 10 −2: 1 centilux: 1 centilux: Quarter Moon 10 −1: 1 decilux: 2.5 decilux: Full Moon on a clear night ...

  7. Bortle scale - Wikipedia

    en.wikipedia.org/wiki/Bortle_scale

    Bright suburban sky 5.1–5.5 18.5–19.25 the zodiacal light is invisible; light pollution makes the sky within 35° of the horizon glow grayish white; clouds anywhere in the sky appear fairly bright; even high clouds (cirrus) appear brighter than the sky background; surroundings are easily visible; the Milky Way is only visible near the zenith

  8. Sky - Wikipedia

    en.wikipedia.org/wiki/Sky

    The sky is an unobstructed view upward from the ... Green flashes may also be observed at the horizon in association with the Moon and bright planets, including Venus ...

  9. Magnitude (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Magnitude_(astronomy)

    A very bright satellite flare can be seen in the night sky. The Greek astronomer Hipparchus produced a catalogue which noted the apparent brightness of stars in the second century BCE. In the second century CE the Alexandrian astronomer Ptolemy classified stars on a six-point scale, and originated the term magnitude . [ 2 ]