Viewing a single comment thread. View all comments

Treczoks t1_ittykpc wrote

Just a wild guess here, but just imagine the original star was bigger than 1.17 sun masses originally, started to compress, and has shed an outer shell of matter during the process while the remaining 0.77 sun masses kept compressing down after having passed a certain threshold.

And a neutron star is not a black hole, so something could leave it, reducing it's mass over time. I'd guess this would be a super slow process, but nobody mentioned how old this thing is, anyway.

2

be-the-people t1_ituchf3 wrote

If it's giving off light and heat then it's losing mass, just very slowly.

5

Chadmartigan t1_itv3vr4 wrote

I read a separate article stating that it's theorized that this star may be comprised of a high level (roughly 1/3 mass) of strange quarks, formed when the much lighter up & down quarks of its constituent nuclei fuse. This is just a theory; this hasn't been observed in any way.

If that is the case, though, I'm not sure how the mechanics of that work. It seems to me that you have to overcome the Pauli exclusion pressure to push two fundamental particles together. But I think this is possible given asymptotic freedom? I guess if it's going to happen anywhere, it would be a neutron(-like) star.

1

favoritedeadrabbit t1_iu0e1ak wrote

“degeneracy pressure” is a term to look up if you find all this interesting. There are a few types.

3

Treczoks t1_itv4lgc wrote

Wow. This ball gets stranger and stranger...

2

danielravennest t1_itub6gb wrote

The thing is, current theory says you can't have neutron stars below 1.4 solar masses. At lower masses you get a "white dwarf", which consists of a soup of atomic nucleii and electrons. Above the critical mass, the protons and electrons are compressed to neutrons, making a neutron star.

So the possibilities are our theory is wrong, our mass estimate is wrong, or it is an odd looking white dwarf and both theory and mass estimate are right.

0

Treczoks t1_itv3cu5 wrote

"can't have" as in "A mass packed down to neutrons like a neutron star would expand and leave the neutron star phase if it dropped below the mass threshold"? My idea was that once it is packed down to neutrons, it will stay there, and not return to atoms with protons and electrons in the mix. So I thought that this could have happened just like with supernovas that shed an outer layer while the core keeps compressing.

I understand that from the plain mass aspect, you need more tha 1.4 sun masses to compress the nuclei+e soup down to neutrons. But in the end what you need is some energy to do his compression. It might come from mass, it might come from a solar collision, or, what I suggested, that the original mass was sufficiently critical to compress the core down to neutrons, but during this process something happened (radiation energy coming from the collaps of the core?) that blew the not-yet-converted-to-neutron outer parts away. Of course, this idea can only work if a neutron star will stay a neutron star once converted.

2

danielravennest t1_itvgcvz wrote

> But in the end what you need is some energy to do his compression.

Gravity is what is doing the compression. The self-gravity of all the material squeezes the center into neutronium (a solid mass of neutrons).

1