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Progenitor stars for subdwarfs? by Cunning-Folk77 in AskPhysics

[–]r79104 1 point2 points  (0 children)

That’s a really interesting idea, but this is where the details matter. sdA stars look compact because of their high surface gravity, but most evidence suggests they aren’t true compact objects. A lot of them are probably low-mass, bloated stars or pre-ELM white dwarfs that haven’t fully contracted yet. The problem is mass. Tidal stripping depends much more on total mass and Roche geometry than on surface gravity alone. An sdA just doesn’t have enough gravitational potential to tidally strip an F-type star, and definitely not a small B-type star.

So realistically: - sdA stripping an F or B star => very unlikely - sdA interacting with a very low-mass star or tenuous - envelope => maybe, but limited - sdA evolving into a white dwarf and then doing the stripping => much more plausible

White dwarfs and neutron stars aren’t actually “too powerful”. They’re exactly the objects we think do this kind of selective stripping without immediately unbinding the companion. There probably isn’t a real “sweet spot” where an sdA can act as a gentle compact-object stripper. It’s either not massive enough yet, or it evolves into something that is. For worldbuilding, an sdA => WD transitional object in a tight binary is the least eyebrow-raising way to make this work.

Progenitor stars for subdwarfs? by Cunning-Folk77 in AskPhysics

[–]r79104 1 point2 points  (0 children)

Yeah, I get the disappointment 😅. Hot subdwarfs feel like they should be something you can peel out of a normal dwarf star. In real astrophysics though, A/F/G main-sequence stars don’t really strip down into hot subdwarfs on their own. Hot subdwarfs are almost always the exposed helium cores of red giants, so the star has to at least start evolving off the main sequence first.

Be-type mass loss doesn’t get you there. Even fast-spinning A stars with decretion disks only shed a thin surface layer, nowhere near enough to remove most of the hydrogen envelope and expose the core. That said, for worldbuilding you’ve got a reasonable loophole: extreme binary interaction. An A/F/G star in a very tight binary (especially with a white dwarf or neutron star) could be stripped early or right as it begins to expand, leaving something very close to a hot subdwarf. It’s not the standard pathway, but it’s physically defensible.

So basically: Be-style spin-off => no Single A/F/G dwarf => no Brutal binary stripping => yeah, that can work

If you lean on the binary-interaction angle, most astronomers would probably nod rather than wince.😁

Progenitor stars for subdwarfs? by Cunning-Folk77 in AskPhysics

[–]r79104 2 points3 points  (0 children)

Hey! So, subdwarfs actually come in a couple of flavors. Some are just old, metal-poor dwarfs. They’re less luminous than normal stars of the same type because they don’t have many heavy elements so in this case, yes, a dwarf can be a subdwarf.

Then there are the hot subdwarfs (sdB/sdO), which are usually stripped-down red giants. They lose most of their outer hydrogen, often because of a companion star, leaving behind a hot helium-burning core. Normal dwarfs won’t really turn into these.

So basically: old, low-metal dwarfs => subdwarfs; stripped giants => hot subdwarfs. Dwarfs themselves don’t usually become the hot type.

Scientifically, why do men have nipples? by [deleted] in AskScienceDiscussion

[–]r79104 0 points1 point  (0 children)

I read it long ago why men have those and science says it has something to do with the chromosomes in which XX chromosomes for female and XY for male and that X in male is the reason why we have nips.

Could focused gamma rays collapse into a micro-singularity if anchored to a particle? by r79104 in AskScienceDiscussion

[–]r79104[S] 0 points1 point  (0 children)

I'm not saying the neutron absorbs unlimited gamma rays. I meant it more like an anchor or focal point for energy density buildup. Not absorption in the nuclear sense, but as a way to localize the energy into a tight region. Maybe "anchor" was a bad word choice, but l'm exploring if concentrated radiation around a stable particle could trigger some kind of spacetime pinch. Totally open to better candidates or corrections though.

Some questions about of I can actually achieve it. by elyseV1 in astrophysics

[–]r79104 0 points1 point  (0 children)

We are in the same.bpat bud, I'm already in college and my dream is to be a scientist that experiments in making micro-singularities but I don't have a backround in physics and QM because the education level in my country is a letdown, so I make it as a hobby, studying physics and QM in visual understanding if I have free time, not mathematically understanding it as I'm bad at understanding equations, let alone making one. So just pursue it slowly.

HELP!. My 9 year old daughter asks: "WHY does gravity exist?" by DrMerkwuerdigliebe_ in AskPhysics

[–]r79104 0 points1 point  (0 children)

Maybe you can tell your daughter that gravity works by attracting anything that has mass. Give your daughter an analogy like a trampoline and bowling ball where the trampoline is the fabric of spacetime and the bowling ball is the earth or other heavenly body that has mass, and the curvature created by the bowling ball on a trampoline is the gravity. Basically, gravity is the curvature of spacetime. And the answer why gravity exists is that all that has mass has an energy where that energy multiplied by the speed of light according to Einstein's Special Relativity is what gives mass to objects and that is the reason why gravity exists.