Another Strange Streak

Comments and questions about the APOD on the main view screen.
Emoticon Fury
Ensign
Posts: 10
Joined: Thu Oct 21, 2004 6:29 am

Another Strange Streak

Post by Emoticon Fury » Tue Feb 01, 2005 4:20 am

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.

Image

This was taken the night before last with a 50mm lense 1 min exposure. I blew it up 300% to show the line better

Image

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.

Dan Cordell
Ensign
Posts: 99
Joined: Mon Jul 26, 2004 8:55 pm
Location: Michigan Tech

Post by Dan Cordell » Tue Feb 01, 2005 2:48 pm

That is very strange... nice catch!

Hopefully somebody will have an idea.
Dan Cordell, Giant Space Cow

jscotti
Asternaut
Posts: 2
Joined: Thu Feb 03, 2005 2:19 am
Location: Lunar and Planetary Lab

Post by jscotti » Thu Feb 03, 2005 2:52 am

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.

Bad Buoys
Ensign
Posts: 51
Joined: Mon Jan 03, 2005 6:41 pm
Location: Columbia River

Post by Bad Buoys » Thu Feb 03, 2005 9:01 am

Rotate the camera 90 degrees and try the shot again. That will let us know if the streak originates within or external to your sensor.

Does it appear in any other shots by this sensor?

The Meal
Ensign
Posts: 37
Joined: Wed Aug 11, 2004 4:51 pm
Location: Longmont, CO

Post by The Meal » Thu Feb 03, 2005 1:44 pm

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
BSME, Michigan Tech 1995
MSME, Michigan Tech 2000

NATE
Asternaut
Posts: 1
Joined: Thu Feb 10, 2005 8:51 pm

absolutely

Post by NATE » Thu Feb 10, 2005 8:54 pm

your standard UFO.
John 3:16

billyhill
Asternaut
Posts: 2
Joined: Sat Feb 05, 2005 2:42 am

Post by billyhill » Thu Feb 10, 2005 11:30 pm

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.