Green line
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by
CptBowmore
How come there is a green line across the picture? I'm asuming that it got added some way or another and isn't part of the original picture but how should it be classified?
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by
JeanTate
in response to CptBowmore's comment.
It's a well-known artifact, commonly called a #satellitetrail. It's caused by sunlight reflecting off a satellite, which appears to move across the field of view of the SDSS camera. Because of the way the five filters are arranged in front of the CCDs (the real heart of the camera, the detectors), a moving object will show as a colored streak. Red and blue satellite trails are also found among SDSS images. Note that the may be caused by an aircraft, or a meteor.
Yesterday I started "Green sabres" - how easy is it to identify green satellite trails, from PhotoObj parameter values? which asks whether we ordinary zooites can work out what 'galaxies' are in fact satellite trails, based on data already published about them.
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by
CptBowmore
Thanks I'll take a look at the link
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by
ElisabethB
moderator
hi CptBowmore
Do not bother ! The fastest way to recognize satellite trails is just to look for these very green straight lines ! No galaxy looks looks like this ! 😄
Happy hunting ! 😄
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