Transuranic elements in a star

[Moontanman]

I'm not sure if I already posted this if so i apologize.

 

Can this star be explained?

 

https://en.wikipedia.org/wiki/Przybylski%27s_Star

 

 

[Sensei]

The question is which Plutonium isotope is found,

According to

https://en.wikipedia.org/wiki/Isotopes_of_plutonium

"The most stable are Pu-244, with a half-life of 80.8 million years, Pu-242, with a half-life of 373,300 years, and Pu-239, with a half-life of 24,110 years. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. "

[Moontanman]

The question is which Plutonium isotope is found,

According to

https://en.wikipedia.org/wiki/Isotopes_of_plutonium

"The most stable are Pu-244, with a half-life of 80.8 million years, Pu-242, with a half-life of 373,300 years, and Pu-239, with a half-life of 24,110 years. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. "

 

I understand that, but it would appear far more than plutonium is involved..

 

 

 

Przybylski's Star also contains many different short-lived actinide elements with actinium, protactinium, neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium being detected. Other radioactive elements discovered in this star include technetium and promethium.^[11]

[Moontanman]

This about to drive me nuts, am i wrong to wonder what is going on here? We are talking about gigatons of short lived elements being in a star. Elements that do not even exist on Earth or in nature in general. Unless this star is newborn, and even then It's difficult to understand where these elements could have come from. Another problem is that evidently no other star has been found with this transuranic content... 

[Moontanman]

It's so frustrating to post something you are intensely interested in and have either no replies or no serious replies. Seriously guys what gives?  

[J.C.MacSwell]

1 hour ago, Moontanman said:

It's so frustrating to post something you are intensely interested in and have either no replies or no serious replies. Seriously guys what gives?  

Hi Moontanman

I was interested enough to watch the video and found it interesting/puzzling, but unfortunately can't add much. No plausible explanation comes to mind. Hard to believe Aliens would produce enough plutonium and other waste (and then dump it into the star) so presumably it would be naturally caused.

Edited July 30, 2017 by J.C.MacSwell

[Moontanman]

24 minutes ago, J.C.MacSwell said:

Hi Moontanman

I was interested enough to watch the video and found it interesting/puzzling, but unfortunately can't add much. No plausible explanation comes to mind. Hard to believe Aliens would produce enough plutonium and other waste (and then dump it into the star) so presumably it would be naturally caused.

I agree,the idea of aliens dumping planetary masses of these elements in a star is difficult to understand but plutonium is not the only element detected. One at least has a half life so small the entire volume of the Earth is thought to contain less than the volume of a sugar cube at any one time. It's a mystery that, to me at least, would trigger research on a large scale. It's almost like finding an object on the moon shaped like a perfect rendition of human riding a horse statue. No way it could just be ignored.  

The more I look into it the stranger it becomes, but I can find little to no discussion of this star.  This Star is unique in that no other star has been found with transuranic elements in it's atmosphere not to mention the low levels of metals like iron... 

Edited July 30, 2017 by Moontanman

[Area54]

4 hours ago, Moontanman said:

It's so frustrating to post something you are intensely interested in and have either no replies or no serious replies. Seriously guys what gives?  

It is likely that a process for generating these elements will be discovered and their appearance here, while rare, will turn out to be completely natural.

It did remind me that in late 1971 I drafted a short SF story in which aliens established interstellar communication by modifying the spectra of stars. If that turns out to be the case here, then once again I shall have missed out on an opportunity for fame and fortune.

Could you find no papers on the research?

[Bender]

While I know nothing about this: I can formulate a hypothesis: another star went supernova in the vicinity (double star perhaps? ), and this one sucked in large quantities of the debris. 

[Area54]

Przybylski's Star is unusual in several ways:

1. Low concentrations of iron and nickel (slightly lower than the sun)

2. High concentrations of Lanthanides (by two or three magnitudes)

3. Presence of various short-lived isotopes (Unknown? in other stars)

4. High velocity relative to neighbouring stars

5. Rapid oscillations - 12 minute period. (Type for roAp star class.)

It seems likely that most or all of these features are initmately related. Alien garbage disposal corporations need not apply. I would focus on point 2. to establish underlying cause(s).

Here is the link to the original paper announcing the discovery of the peculiar spectrum.

Edited July 30, 2017 by Area54

[Moontanman]

Unless the supernova occurred quite recently, and mean a few centuries,  those isotopes should have decayed, some of them have half lives of hours.

 

https://en.wikipedia.org/wiki/Przybylski%27s_Star

Quote

Przybylski's Star also contains many different short-lived actinide elements with actinium, protactinium, neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium being detected. Other radioactive elements discovered in this star include technetium and promethium.^[11]

 

[John Cuthber]

The phrase "short lived" seems to be a relative term. Most of the elements mentioned have million year life spans. There are a few that are short lived but I think most of them may be decay products of longer lived ones.
It seems we may be looking at the aftermath of an event that happened a million years ago.

Also, as far as I understand it, the synthesis of "heavy" elements in stars doesn't "stop" with uranium. The heavier elements are also made, but they decay.
We don't normally see the heavier ones because we are looking so long after the event.
 

It seems to me, in this case, we have found the ashes of a a supernova or some such mixed into a star before the high z stuff decayed away.

 

[Moontanman]

3 hours ago, John Cuthber said:

The phrase "short lived" seems to be a relative term. Most of the elements mentioned have million year life spans. There are a few that are short lived but I think most of them may be decay products of longer lived ones.
It seems we may be looking at the aftermath of an event that happened a million years ago.

Also, as far as I understand it, the synthesis of "heavy" elements in stars doesn't "stop" with uranium. The heavier elements are also made, but they decay.
We don't normally see the heavier ones because we are looking so long after the event.
 

It seems to me, in this case, we have found the ashes of a a supernova or some such mixed into a star before the high z stuff decayed away.

 

Are you suggesting that elements heavier than uranium can the the decay kay products of lighter atoms? 

[Area54]

5 hours ago, Moontanman said:

Are you suggesting that elements heavier than uranium can the the decay kay products of lighter atoms? 

He appears to be stating that the "short lived" elements identified in the star were produced recently (in astronomical terms) within a nearby supernova. As someone, perhaps yourself, noted earlier the discussion is not much more than waffle until we have identified exactly which isotopes are involved and what their half lifes are.

He is suggesting that if there are any "short lived" isotopes, where short lived is thousands of years or less, that these are decay products of some of the (slightly) heavier "short lived" isotopes with million year (+/-) half lifes.

[Area54]

I've done some further digging and found this is a fascinating topic. As I noted in an earlier post this is an Ap star, noted for its short term oscillations and strong magnetic fields. The magnetic field contributes to the absence of convection in the star which promotes stratification of elements and thus accounts for the anomalous high values for the Lanthanides and REEs. The presence of truly short lived isotopes has been confirmed by multiple investigators, including Technetium with a half life of 17 hours. (I need to double check that).

An obituary on Biddleman led me to a paper by Cowley, which led to one by Mkrtichian, hence to a 2007 paper by Gorierly that appears to answer the problem.

Here is the link to the paper.

Here is the abstract.

Context.

Recent observations have suggested the presence of radioactive elements, such as Tc, Pm, and 84 ≤ Z ≤ 99 elements at the surface of the chemically-peculiar magnetic star HD 101065, also known as Przybylski’s star. The peculiar 35<Z<82 abundance pattern of HD 101065 has been explained so far by diffusion processes in the stellar envelope. However, those processes cannot be called on to explain the origin of short-lived radioelements.

Aims. The large magnetic field observed in Ap stars can be at the origin of a significant acceleration of charged particles, mainly protons and α-particles, that in turn can modify the surface content by interaction with the stellar material. This paper explores to what extent an irradiation proces s resulting from the interaction of the stellar material with energetic particles can by itself account for both the abundances determined by observation on the surface of the chemically peculiar star HD 101065 and the presence of unstable elements.

Methods.Due to the unknown characteristics of the accelerated particles that could be held responsible for this nuclear process, a purely parametric approach is followed, with the proton and α-particle flux amplitude and energy distribution taken as free parameters, as well as the total fluence

Results. This kind of irradiation process, at least for high fluences, can lead to a rich nucleosynthesis, including a significant production of Z >30 heavy elements, as well as radioelements like Tc and Pm, and even transuranium. In this respect, the energy spectrum of the accelerated particles plays a crucial role. Many observational aspects of HD101065’s composition can be explained quantitatively.

Conclusions. The possible existence of high-fluence irradiation events need to be confirmed by hydrodynamics simulations but, most of all, by spectroscopic observations through detecting short-lived unstable elements on the surface of chemically peculiar stars.

 

That rather seems to be game, set and match over the aliens.

 

 

 

[Moontanman]

I thank everyone who looked into this, since Przybylski's Star appears to be unique in it's transuranium elemental content, no other such star has been detected I thought investigation was warranted. While the video did indeed include aliens as a possible source I only included it for informational purposes not to assert "aliens" my bad, I apologise....  

[Area54]

1 minute ago, Moontanman said:

I thank everyone who looked into this, since Przybylski's Star appears to be unique in it's transuranium elemental content, no other such star has been detected I thought investigation was warranted. While the video did indeed include aliens as a possible source I only included it for informational purposes not to assert "aliens" my bad, I apologise....  

Not at all. It was the alien reference that grabbed my attention. I was rather hoping it would be more of a possibility than has (apparently) turned out to be the case.

Also note that Gorierly has only proposed a hypothetical solution. I can find nothing in subsequent literature that any of the tests he proposed have been carried out. The attitude appears to be "ah yes, that would explain it. I have more interesting problems to work on than to confirm that." I shall probe a little further and see if I can turn up anything else buried in the several papers on Ap stars in general that I have located with my literature searches today.

[Area54]

There is a rich treasure trove out here. First this 2008 paper acknowledges Gorierly's proposal, but attributes the high speed particles, which generate the short lived isotopes, not to the actions of the magnetic field, but to a companion neutron star. I find this unconvincing, but that is based on my ignorance of the ease or difficulty of detecting neutron stars. I imagine that if there were a neutron star companion it should have been detectable by now. No subsequent papers citing this one discuss the NS hypothesis further.

It seems that HD101065 is not the only star with transuranic content in the photosphere. HD465 is also anomalous. This is mentioned in passing in a couple of papers. I have not yet tracked down the original research.

In an earlier post I mistakenly stated the half life of Technetium was 17 hours. I should have referenced the half life of ¹⁴⁵Pm as 17.7 years. (How time flies when you are having fun.)

[John Cuthber]

19 hours ago, Moontanman said:

Are you suggesting that elements heavier than uranium can the the decay kay products of lighter atoms? 

No, I' was suggesting- more or less as Area54 suggested, that these superheavy elements were produced in some very energetic process- supernova, neutron stars colliding- whatever.
If you smash tiny bits off a neutron star, you essentially create heavy nuclei. The "stuff" of nuclei and neutron stars is fairly similar (at least, compared to just about anything else).

So making almost any nuclei you want  by this process is "plausible".

Technetium is very short lived, but -as in earthbound reactors, it can be made by fission.
There are plenty of fissionable materials present so why wouldn't you find Tc?

Also there are "million year" isotopes of Tc so it could have been made in the same  event as some of the other elements.

I suspect that we will struggle to identify the isotopes for these elements in their star. The spectral broadening due to other factors- notably temperature- in a star will swamp any isotopic  effects on the optical spectra.

[Area54]

8 hours ago, John Cuthber said:

I suspect that we will struggle to identify the isotopes for these elements in their star. The spectral broadening due to other factors- notably temperature- in a star will swamp any isotopic  effects on the optical spectra.

It turns out that astronomers have this one at least partly covered - struggle they may, but victorious they are. For example, from "The calcium isotopic anomaly in magnetic CP stars", Cowley and Hubrig:

" Chemically peculiar stars in the magnetic sequence can show the same isotopic anomaly in calcium previously discovered for mercury-manganese stars in the non-magnetic sequence. In extreme cases, the dominant isotope is the exotic ⁴⁸Ca. Measurements of Ca II lines arising from 3d-4p transitions reveal the anomaly by showing shifts up to 0.2 Å for the extreme cases - too large to be measurement errors."