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Visible-light astronomy has existed as long as people have been looking up at the night sky, although it has since improved in its observational capabilities since the invention of the telescope, which is commonly credited to Hans Lippershey, a German-Dutch spectacle-maker, [1] although Galileo played a large role in the development and ...
Astronauts who had recently returned from space missions to the Hubble Space Telescope, the International Space Station and Mir Space Station reported seeing the LF under different conditions. In order of decreasing frequency of reporting in a survey, they saw the LF in the dark, in dim light, in bright light and one reported that he saw them ...
An example of this phenomenon is when clean air scatters blue light more than red light, and so the midday sky appears blue (apart from the area around the Sun which appears white because the light is not scattered as much). The optical window is also referred to as the "visible window" because it overlaps the human visible response spectrum.
The origin of this effect is rapidly changing variations of the optical refractive index along the light path from the object to the detector. Seeing is a major limitation to the angular resolution in astronomical observations with telescopes that would otherwise be limited through diffraction by the size of the telescope aperture .
The human eye discards what it sees from split-second to split-second, but photographic film gathers more and more light for as long as the shutter is open. The resulting image is permanent, so many astronomers can use the same data. It is possible to see objects as they change over time (SN 1987A is a spectacular example).
The main source of information about celestial bodies and other objects is visible light, or more generally electromagnetic radiation. [51] Observational astronomy may be categorized according to the corresponding region of the electromagnetic spectrum on which the observations are made. Some parts of the spectrum can be observed from the Earth ...
The same happens with objects purposefully placed in space, such as satellites. Read more: ... A 6.5 magnitude is generally the dimmest object the human eye can see. The mini-moon's magnitude is ...
Observation and measurement of starlight through telescopes is the basis for many fields of astronomy, [2] including photometry and stellar spectroscopy. [3] Hipparchus did not have a telescope or any instrument that could measure apparent brightness accurately, so he simply made estimates with his eyes.