Famous Places – Artifices
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No telescope or data processing system is perfect. Sometimes meteors or satellites appear in the field of view of the telescope. The images below show some of these “gimmicks” – errors and surprises in the data. The Navigator does not display the artifacts correctly. To learn more about how SDSS data is collected and processed, go to the section on SDSS. |
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The red “ghost” is the result of the reflection inside the telescope of light emitted by a very bright nearby star. Even when the reflections are very weak, very bright objects still cause detectable artifacts. |
The blue “ghost” is the result of light reflecting from a very bright nearby star inside the telescope. It is blue because the reflection occurred in the blue filter detector. |
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Satellite moving around the earth with low orbit. The variation in light intensity is due to the rotation of the satellite. |
Bright meteor captured at the moment of entering the Earth’s atmosphere. The trail is green because the meteor image was captured by one of the 5 SDSS filters only. |
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Satellite moving around the earth with low orbit. The variation in light intensity is due to the rotation of the satellite. The satellite has crossed the field of view of the telescope in a very short period of time. It is red because it has been detected by the red detector, not because the meteor is red. |
Each bright star is marked with a “cross.” This pattern is called ‘diffraction spike‘, is because the light is scattered by the four beams that support the secondary mirror of the telescope. |
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Each star, although bright, is a point of light. Stars appear as extensive or haloed objects, due solely to scattering of light within the telescope. The faint horizontal stripes are due to “spillage” of the charge inside the detector. On the original, uncleaned magnets, these effects were much stronger, but using our software we have successfully removed most of these defects. |
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