What is the most massive element that we observe in nature?

Factual Questions
1

I was just reading in wikipedia that we see californium in the spectra of supernovae. Do we see heavier stuff as well?

Thanks,
Rob

2

Aha! That might explain the creation of Planet Hollywood.

3

Gee, I thought this question would have been right up some dopers’ alley. Let’s see if a little bump works.

Thanks,
Rob

4

I love you.

5

I’d suggest that what we have here is two questions:

1 - What is the highest element creatable by nature?

2 - Have we looked for it and if so, have we found it?

I recall reading that we have found the remains of transuranic elements - namely the decayed products - but cannot recall the cite.

6

Depending on what you want to define as an ‘element’, Neutronium (what neutron stars are made from) is the densest we’ve ever observed. (It would, incidentally, sit on the periodic table at position zero, as it has no protons (or electrons, for that (degenerate) matter).) If you don’t like anything you can’t even contemplate making compounds of being called an element, then I think one natural reactor in Africa made substantial amounts of Plutonium out of Uranium well before most life as we know it even existed.

7

Well, if you put it that way, surely the densest is whatever’s inside a singularity.

8

Inside a singularity physics as we know it breaks down. Neutronium is the best we’ll do with the knowledge we have.

9

He asked what’s observable - I don’t think neutronium exactly counts. According to Wikipedia’s article on supernova nucleosynthesis:

Unfortunately, they don’t give a reference for that statement, but I suspect it’s D. D. Clayton, “Handbook of Isotopes in the Cosmos” 2003, the only recent reference given for the article.

10

Nametag: Neutron stars have to be made of something, no? I suppose there are varying degrees of observability: We can’t observe the backs of our own heads directly. Maybe it’ll be easier if we ignore degenerate matter, but that ignores a good deal of the wonder of the Universe as far as I’m concerned. It’s up to the OP.

11

Yes, but not 100% pure neutrons. Go read the Wiki Neutron Star article for more.

12

Ah, OK. I thought the matter was a lot closer to being settled than that. I suppose if we wanted to propose ultradense ultratheoretical matter that isn’t a mere singularity, we’d be talking about preon-degenerate matter. Since it seems that preons (no relation to the degenerate proteins called ‘prions’) might not actually exist, though, that would just be silly.

13

I wasn’t referring to density. I was referring to atomic mass. And I guess that Cf is the answer according to the above post, unless someone can cite something higher on the periodic table. (I seem to remember reading one time that you could think of a neutron star as a single nucleus and as such, that would be the most massive element found in nature, but I may not be recalling that correctly.)

If Cf, is indeed the most massive element observed, does that mean that there are no “islands of stability” in transuranic elements or that supernovae don’t have the requisite energy to create them?

Thanks for your help,
Rob

14

How dense would a quantity of superheavy element eka-thorium be?

AKA unbibium?

15

I think most people would consider an element to be bound by the strong nuclear force. Since neutron stars are bound by gravity, I’d say that discounts them.