"Companion" particles

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drharmon
Posts: 2
Joined: Tue Sep 19, 2006 12:55 pm
Location: Georgia

"Companion" particles

Post by drharmon »

First time at forum although have been searching since the beginning. An observation, comment and suggestion.
I have noticed that very nearly all smaller tracks have a companion particle captured at the surface and within 5 or 6 microns of the "splashdown" point. Might these be a less dense companion particle to the tracking particle and originally held by gravity, magnetic/electrical field or by some as yet unknown force? (Expect the unexpected.) Particularly good examples: 6010096V1 and 659190V1 although most show it. Might this demonstrate the early stage of accretion? Regardless, it may well be worth collecting several of these "companion" particles for future analysis for composition and origin and, they should be easier to gather.
David
David

jsmaje
Posts: 616
Joined: Tue Aug 15, 2006 8:39 am
Location: Manchester UK

Re: "Companion" particles

Post by jsmaje »

drharmon wrote:First time at forum although have been searching since the beginning. An observation, comment and suggestion.
I have noticed that very nearly all smaller tracks have a companion particle captured at the surface and within 5 or 6 microns of the "splashdown" point. Might these be a less dense companion particle to the tracking particle and originally held by gravity, magnetic/electrical field or by some as yet unknown force? (Expect the unexpected.) Particularly good examples: 6010096V1 and 659190V1 although most show it. Might this demonstrate the early stage of accretion? Regardless, it may well be worth collecting several of these "companion" particles for future analysis for composition and origin and, they should be easier to gather.
Well, I originally thought so too, see: http://stardustathome.ssl.berkeley.edu/ ... ight=#6565. Real tracks can certainly have subsiduary branches, as well-visualised in certain pictures in these forums (but for the life of me I can't find them now - sorry!). But then I learned that most of the calibration movies are 'fakes', made from only a very small number of real tracks from other sources, and digitally manipulated at various sizes and orientations into otherwise blank movies (with the double jpeg compression artefacts that are an obvious give-away, though fooling many folk so far into thinking they've found something special).

So, I reckon the small 'companion' specks we've both noticed are most likely the same one(s) repeated at different sizes and angles within calibration movies. And in case you didn't know, you can't actually recall calibration movies by number; trying to do so only brings up identically-numbered real movies. Try these links to your movie numbers: 6010096V1 and 659190V1. If I'm right, they're not the ones you were referring to.

Anyhow, I must say that the second looks most artistic (in a Turneresque 'Storm At Sea' sort of fashion), though sadly lacking any track!

fjgiie
DustMod
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Calibration Movies

Post by fjgiie »

Image
Calibration Track with a Companion

Hi David, Welcome to the forum -

jsmaje did a very good job explaining this, I will expand on what he said. It sounds to me you are talking about a positive calibration movie. These often have the companion "particle track" like the photo above. (near the center)

These calibration movies have a "fake" track placed in a clear real movie and are used to give you a score, and train you to tag or click a track. There is no stardust in these calibration movies. The 45 or so tracks with stardust at the end of them will be found in the "real" movies. That is where the gold is.

Look at the other movies that do not award any points when you click them, they are real. They contain the dust tracks that we are looking for.

Thanks

fjgiie

jsmaje
Posts: 616
Joined: Tue Aug 15, 2006 8:39 am
Location: Manchester UK

Post by jsmaje »

This is the sort of picture I was referring to (notice the subsiduary branches/tails), though these are in fact cometary dust tracks, and much larger than IS tracks are likely to be:

Image

drharmon
Posts: 2
Joined: Tue Sep 19, 2006 12:55 pm
Location: Georgia

"companion" particles

Post by drharmon »

Many thanks to jsmaje & fjgiie for thoughtful and enlightening responses.
David

the moon
Posts: 177
Joined: Thu Aug 03, 2006 12:34 am

Post by the moon »

See my post in this topic for my explanation of what these companion particles really are.
http://stardustathome.ssl.berkeley.edu/ ... php?t=1199

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