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Old 18-01-2012, 08:40 AM
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what do cosmic rays look like in subs?

Over at POTN in the astro section a guy has posted this image, second and third ones down:
http://photography-on-the.net/forum/....php?t=1138088

Speculation as to what it is. Some saying tumbling meteor, others that Russian satellite. I was thinking they'd be pretty much straight lines. I've read about cosmic rays, and pretty sure I saw an image with a curved or wobbly line, but not as long as this one.

Any speculation as to what it could be?
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Old 18-01-2012, 10:25 AM
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It's a hair on the lens.
Or a fire fly.
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Old 18-01-2012, 10:41 AM
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G'day Nettie. I had thought that, but then thought if it was a hair it would be dark/black, because even if light was reflecting off the hair, it wouldn't be similar brightness to the stars etc? It's also sharply in focus along with the stars. A hair on the lens would be quite blurry, no?
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Old 18-01-2012, 10:54 AM
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Straight line is a meteor, one with the dots is an aircraft and curved one is light reflected from flying insect. I get hundreds of them on my meteor capture camera every month.
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Old 18-01-2012, 03:36 PM
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That's a bug flying past.
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Old 18-01-2012, 03:47 PM
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I'm quite certain it's a trail from the brightest star, the only star of that brightness in the FOV hence one trail. The camera would have been moved (or perhaps sagged on the tripod) and it moved at such a rate that only the trail of the brightest star was recorded. I see the same often when a tripod head slips or I kick the tripod or the trakcing stops, or I step on the nearby decking which moves the tripod enough to show a trail or whatever. I would say there's a reasonable chance the second brightest star in the image has a similar trail if the levels were pushed extreme enough, but not necessarily, as it depends on the exposure details.

it's certainly not a cosmic ray, they look very different to that in my experience.
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Old 18-01-2012, 05:12 PM
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This is how conventional wisdom say the cosmic ray hit parallel to CCD sensor looks like
http://www.iceinspace.com.au/forum/a...chmentid=84088

But I'm not so sure about it as similar image taken with Star Analyser showed spectrum.
http://www.iceinspace.com.au/forum/a...chmentid=83915

Last edited by Karls48; 18-01-2012 at 06:22 PM.
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Old 18-01-2012, 05:22 PM
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Thanks all. Was all just out of interest and learning.
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Old 18-01-2012, 05:53 PM
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Quote:
Originally Posted by Karls48 View Post
This is how conventional wisdom say the cosmic ray hit parallel to CCD sensor looks like
http://www.iceinspace.com.au/forum/a...chmentid=84088

But I'm not so sure about it as similar image taken with Star Analyser shoved spectrum.
http://www.iceinspace.com.au/forum/a...chmentid=83915
I have never had a cosmic ray form such a long trail. All of my trails are short. I have attached a couple of examples from a dark frames. The second one is about the longest I get. Both are 1:1 crops.
Attached Thumbnails
Click for full-size image (cosmic1.JPG)
53.7 KB25 views
Click for full-size image (cosmic2.JPG)
96.7 KB25 views
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Old 18-01-2012, 06:21 PM
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To capture meteors the camera and computer was running every night for last four or five years. Radio meteor capture receiver and another computer was running non stop 24 hrs. During that time I captured lot of strange things in night sky. Only few pic are hard to explain - one with spectrum is one of them. I stopped it about six moths ago because cost of power was getting too expensive.
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Old 18-01-2012, 06:42 PM
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Quote:
Originally Posted by OzRob View Post
I have never had a cosmic ray form such a long trail. All of my trails are short. I have attached a couple of examples from a dark frames. The second one is about the longest I get. Both are 1:1 crops.
Those curved lines there are what I understood to be cosmic rays. No?
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Old 19-01-2012, 08:26 AM
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Quote:
Originally Posted by Karls48 View Post
But I'm not so sure about it as similar image taken with Star Analyser showed spectrum.
http://www.iceinspace.com.au/forum/a...chmentid=83915
In an OSC camera (usually RGGB) any line will have multi-coloured pixels, unless it happens to exactly follow the 45 degree line of green pixels when it will be purely green.
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Old 19-01-2012, 10:04 AM
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Quote:
Originally Posted by troypiggo View Post
Those curved lines there are what I understood to be cosmic rays. No?
Yes, but so is the straight line in the second image. There are quite a few in them as they are 30 minute darks.
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