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Przybylski's Star

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#1 Ohmless

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Posted 09 November 2019 - 04:05 AM

Just learned tonight that apparently what I was taught in my chemistry/physics undergrad classes was inaccurate in that transuranic elements can exist in nature.  I was told that Uranium was the heaviest element in nature at both the University of Michigan and at Michigan State University back in the 1990's.

 

https://ui.adsabs.ha.....739P/abstract

 

https://ui.adsabs.ha.....460G/abstract

 

https://ui.adsabs.ha......89G/abstract

 

https://ui.adsabs.ha.....149W/abstract and "Intelligent Life in the Universe" by I. S. Schklovskii and Carl Sagan, 1966 both propose the possibility that an alien civilization could have used their star as a nuclear dumping ground or put heavy artificial elements into their star as a marker that they have civilized life in that system. 

 

There is also the odd possibility that the short lived half life elements are degradation products from heavy stable elements that we haven't been able to synthesize on Earth yet.

 

Another bizarre thing about this class of star is that they are very low in Iron.  This makes the case that the heavy elements came from a supernova or a neutron star less likely.

 

 

 

Please be respectful in this discussion so it won't get shut down. There is no proof that this is or isn't a sign of an alien civilization, just different hypothesized origins for the spectroscopic findings from a bizarre star.  There are plenty of youtube videos about this mystery object for those that are interested.


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#2 Brett Waller

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Posted 09 November 2019 - 06:57 AM

Naturally-occurring, transuranic elements were predicted in the 1950's and were found at several locations in the 1.7 billion year old Oklo reactor in Gabon in the early 1970's, which was the subject of several articles in Scientific American and elsewhere.  It was common knowledge in the Geophysical Sciences Department at Old Dominion University when I studied there in the early 1980's, although my General Chemistry text had the same erroneous statement about trans-Uranic elements not occurring in nature, and also that Technetium, the lightest element with all its isotopes radioactive, was not known from nature. In fact, Technetium also was known from the Oklo reactor and had been identified in the spectra of Red Giants, and I seem to recall SBIG having an example of that on their web page as part of their advertising for their self-guided spectrograph. So, the moral of the story is to always take everything with a grain of salt and evaluate the evidence for yourself.

 

Thanks for the interesting references on Przybylski's Star. I'm looking forward to reading them.

 

Brett


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#3 DaveC2042

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Posted 09 November 2019 - 04:43 PM

Interesting.

I always thought the absence of trans-uranic elements and Technetium was simply due to the short half-lives of all the isotopes, and the absence of a decay path from something abundant. I didn't think it was suggested that they weren't being created.

But it's a long time since I studied it.
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#4 Pess

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Posted 24 November 2019 - 08:36 AM

 …..or put heavy artificial elements into their star as a marker that they have civilized life in that system.

 


 

I guess I would ask why on Earth (bad pun) would you want to put  a lighthouse to your system?

 

So some advanced race knows where to invade for already abundant & refined resources?

 

Pesse (Like hanging a sign around your own neck say'n, 'I taste like chicken'.) Mist 


Edited by Pess, 24 November 2019 - 08:37 AM.

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#5 HaleBopper

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Posted 24 November 2019 - 10:51 AM

I seemed to recall from my university years in the 90s that certain transuranium elements do occur in nature in trace amounts, and are therefore naturally occurring.  I had a look through my old text book, "Advanced Inorganic Chemistry 5th Edition" by F. Albert Cotton and Geoffrey Wilkinson.  On page 980 it's stated that Neptunium and Plutonium exist in minute amounts in nature as a result of neutron reactions with uranium isotopes. They are not the remnants from primordial formation, however. All other actinides are synthetic according to my reference.

 

However, in contradiction, this article: https://www.scientif...nic-elements-s/

 

does state that Plutonium-244, discovered in the environment with a half-life of 80 million years has existed since the creation of Earth.

 

As to technetium, on page 850 is does mention that traces exist in nature due to spontaneous fission of uranium. This video has a nice talk on technetium and mentions the Oklo reactor:

 

https://www.youtube....h?v=ud5c1TVkcnU


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#6 star drop

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Posted 16 December 2019 - 08:14 PM

Just learned tonight that apparently what I was taught in my chemistry/physics undergrad classes was inaccurate in that transuranic elements can exist in nature.  I was told that Uranium was the heaviest element in nature at both the University of Michigan and at Michigan State University back in the 1990's.

 

https://ui.adsabs.ha.....739P/abstract

 

https://ui.adsabs.ha.....460G/abstract

 

https://ui.adsabs.ha......89G/abstract

 

https://ui.adsabs.ha.....149W/abstract and "Intelligent Life in the Universe" by I. S. Schklovskii and Carl Sagan, 1966 both propose the possibility that an alien civilization could have used their star as a nuclear dumping ground or put heavy artificial elements into their star as a marker that they have civilized life in that system. 

 

There is also the odd possibility that the short lived half life elements are degradation products from heavy stable elements that we haven't been able to synthesize on Earth yet.

 

Another bizarre thing about this class of star is that they are very low in Iron.  This makes the case that the heavy elements came from a supernova or a neutron star less likely.

 

 

 

Please be respectful in this discussion so it won't get shut down. There is no proof that this is or isn't a sign of an alien civilization, just different hypothesized origins for the spectroscopic findings from a bizarre star.  There are plenty of youtube videos about this mystery object for those that are interested.

That is a very compelling reason to get the highest resolution spectrograms possible to look for lines that we have not found before.


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