Another Strange Streak
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- Ensign
- Posts: 10
- Joined: Thu Oct 21, 2004 6:29 am
Another Strange Streak
Seeing how the other strange streak thread made 140 and some odd pages. I thought some people would like to have a crack at this one.
I was going thru some images I took of m42 and I noticed this wierd line that occurs in both sets of pictures.
This was taken the night before last with a 50mm lense 1 min exposure. I blew it up 300% to show the line better
Same spot 1 night later 200mm lense 100% crop. Notice the faint line in the same spot.
At first I figured it was something on the sensor but when I lined up the two images in pshop and the lines do not occur in the same spot of the sensor. I cant be the lense because theyre two different lenses with two different filters. The thing that strikes me as odd is that it doesnt trail vertically like anything else leading me to believe its something with the camera. Any Ideas? Like I said this is the same spot, 24 hours apart with 2 different lenses. I can provide the RAW files to anyone who wants them.
I was going thru some images I took of m42 and I noticed this wierd line that occurs in both sets of pictures.
This was taken the night before last with a 50mm lense 1 min exposure. I blew it up 300% to show the line better
Same spot 1 night later 200mm lense 100% crop. Notice the faint line in the same spot.
At first I figured it was something on the sensor but when I lined up the two images in pshop and the lines do not occur in the same spot of the sensor. I cant be the lense because theyre two different lenses with two different filters. The thing that strikes me as odd is that it doesnt trail vertically like anything else leading me to believe its something with the camera. Any Ideas? Like I said this is the same spot, 24 hours apart with 2 different lenses. I can provide the RAW files to anyone who wants them.
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- Ensign
- Posts: 99
- Joined: Mon Jul 26, 2004 8:55 pm
- Location: Michigan Tech
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Your trail is almost certainly a geosynchronous satellite. From mid norhtern latitudes, the parallax for a geostationary satellite puts them at around -5 or -6 degrees declination. If you tracked on the stars, they will drift in RA approximately the length of the exposure (i.e., a 5 minute, or 300 second exposure will trail roughly 5 minutes of RA - actually different by the sidereal/diurnal rate differences, or 1.0027 times faster than your wall clock). I'd say the trails in both images are very close to a minute of RA long. If they were taken approximately at the same time of night, the same satellite will be in roughly the same location (more correctly, if they are taken 1 sidereal day apart, they will appear at the same location). But there are many geosynch satellites to accidently shoot and they are as bright as around 9th magnitude as I recall. If you set your camera up without tracking, you can image them pretty easily with a good digital camera these days.
Jim.
Jim.
You can track the earth-orbiting satelites (enter your latitude and longitude) over on http://www.heavens-above.com . That should tell you whether this is a geosynchronous orbiter or not.
~Neal
~Neal
BSME, Michigan Tech 1995
MSME, Michigan Tech 2000
MSME, Michigan Tech 2000
jscotti wrote:Your trail is almost certainly a geosynchronous satellite. From mid norhtern latitudes, the parallax for a geostationary satellite puts them at around -5 or -6 degrees declination. If you tracked on the stars, they will drift in RA approximately the length of the exposure (i.e., a 5 minute, or 300 second exposure will trail roughly 5 minutes of RA - actually different by the sidereal/diurnal rate differences, or 1.0027 times faster than your wall clock). I'd say the trails in both images are very close to a minute of RA long. If they were taken approximately at the same time of night, the same satellite will be in roughly the same location (more correctly, if they are taken 1 sidereal day apart, they will appear at the same location). But there are many geosynch satellites to accidently shoot and they are as bright as around 9th magnitude as I recall. If you set your camera up without tracking, you can image them pretty easily with a good digital camera these days.
Jim.
Yep! Can hardley image this area without these offset streakes appearing from time to time playing tag or follow the leader, almost.