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Pure iron meteor spectrum

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BillW's picture
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Pure iron meteor spectrum

Captured another exceptional meteor spectrum last week. Sadly didn't get the zero order but it must have been bright to produce such a spectacular result. Even better than the the HD Perseid and at least I know what I'm looking at this time...

; - ))

Very distinct line groups make it an easy fit. Also interesting to note that there are no strong near IR atmospheric lines so I can say with some certainty that it had a low Vg.

Over 52 major lines plus more fainter lines in the red end of the spectrum (cropped off in this graph).

...and of course my customary colourised version, just gorgeous! As well as being the best Fe meteor spectrum I've ever seen (amateur or pro) this one now has the record for the highest resolution meteor spectrum I've captured...( so far!)

cheers,

Bill.

PS Edit.

Taken with a ZWO174 mono camera, 25mm f1.3 lens and a 600 lines/mm fused silica substrate UV grating.

andrew.j.smith1905's picture
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Spectrum

I checked the date to see if were a firework! Very clear.

Regards Andrew 

BillW's picture
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Could be, LOL!

Could be, LOL!

A R Pratt's picture
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Pure iron meteor spectrum

Hi Bill,

Very nice results.

My Leeds_N camera was clouded out at that time, unfortunately. We'll see if any other stations were successful and I'll let you know.

Cheers,

     Alex.

BillW's picture
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Dear oh Dear, just as well I

Dear oh Dear, just as well I said "some" certainty....!

I've been studying the original image very closely and what I thought might have been faint second order lines appear to be in fact some of the very lines I thought were not present. There is the faintest hint of the 777.4nm O line. So it was "probably" traveling at a lowish Vg!

Always be skeptical, LOL!

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Meteor showing predominantly iron in its spectrum

It's a beautiful spectrum. It reminds me to use the arc spectrometer I mentioned, obtain some pure iron (or as close as one could get in the iron grades) then obtain a spectrum. It's an old spectrometer which I need to work out how to fix a camera to record the spectrum over the full wavelength range.  I have somewhere, a spectrum of iron and all the major lines already printed in a fold out booklet of several A4 pages long (there are a lot of lines with relative intensities). I will get that copied.  It would be nice to discover some exotic elements. But because of the binding energies of the atoms, there is a minimum which occurs around the atomic weight of iron, which I think? means iron is expected to be predominant in abundance (in the nuclear fusion processes of stars), next to cobalt and nickel in the periodic table.  I will run cobalt and nickel. Might take me some time because I need a suitable connection to the spectrometer - if it still works?

BillW's picture
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HI,

HI,

Sounds great! The lines I've got from the NIST site indicate the Cobalt and Nickel lines are just out of reach in the UV for my system.

Titanium and Vanadium have been reported in meteor spectra but I've never conclusively ID'd those elements. It might be possible now I've got to this level of resolution and sensitivity!

Cheers,

Bill.

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Iron meteor spectrum

I will add cobalt, nickel, and titanium and vanadium to the list - that is, if I can get the thing to work and add a camera, so a long term project which can be dipped into. The data will build up.  I'll have to check that I have some vanadium and titanium, but if not, I may have a steel with some in. But obviously better to have the pure stuff so I know all the lines come from one element. The amounts in steel are often such that the spectrum will be dominated by iron, and some lines will be difficult to see if they are not as intense.  Anyone got any pure vanadium and titanium? I'll gratefully accept a small chunk, plate. Just has to be a surface area of at least 2 inches.

BillW's picture
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Hi All,

Hi All,

After tweeting a re-worked spectrum it seems the meteor was captured on an all sky system (Jamie in Lochearnhead). He estimates it was -3.

I decided to re-work the spectrum as I hadn't really paid much attention to the "thermal tail" between 550nm and 650nm. With the increased resolution I now have I'm more confident about identifying more exotic lines.

It looks like there are some weak lines from Tungsten, Vanadium and Manganese in the mix! I'm pretty sure there'll be Nickel in the meteoroid but these tend to have their strongest emission in the deeper UV, just beyond my detection limit.

This one really was a cracker and a step forward in observation capability. There are some older observations claiming up to 70 lines in a spectrum but that was based on a spectrum that actually had 27 native lines in the image. The assumption was that the other lines were there because they had emissions at particular wavelengths and were blended together. Using that method and modern data I could claim well over 100 lines here, but I'm not sure if that is really honest science. Anyway, from my element list I count 60 native lines in this spectrum without any assumptions of blending.

cheers,

Bill.