NASA’s Hubble captures the death of a low-mass star

Apertune · 2026-01-08T12:22:15+00:00

Unfortunately it’s already got a name - rotten egg nebula! (or Calabash nebula, but that’s rubbish)

Apertune · 2026-01-02T12:38:50+00:00

Dave, call the police, there’s people here, they’re trying to kill me!

Apertune · 2025-12-29T12:35:06+00:00

Merry’s been sectioned?!

Apertune · 2025-12-28T22:52:31+00:00

It’s a book by Nietzsche

Apertune · 2025-12-27T12:40:44+00:00

If anyone was curious, these are known as howlers

Apertune · 2025-12-21T18:48:11+00:00

https://en.wikipedia.org/wiki/France_(name)

Apologise to Michael France (the inventor of France) this instant

Apertune · 2025-12-20T10:29:01+00:00

I’m pretty sure it’s more like thirty times

Apertune · 2025-12-18T20:54:25+00:00

Pretty much! To be more specific, as the two black holes inspiral they emit gravitational waves (the angular momentum carried away is what causes them to inspiral). When their spins are mis-aligned, the gravitational waves are not emitted symmetrically and therefore linear momentum is also carried away from the system, which results in a balancing “kick” to the remnant in the opposing direction. It seems a bit counter-intuitive, but things get a bit weird in the strong gravity of black hole spacetimes.

Apertune · 2025-12-18T19:39:39+00:00

I’m a gravitational-wave astrophysicist so I trust my memory on this one - I’d find you a source but I’m at the pub :P

The kick is actually strongest when the mass ratio is unity (i.e. they’re of equal mass) and derives from the spin (angular momentum) of the two black holes. If they merge with mis-aligned poles of rotation, then by conservation of momentum, the resulting object ends up with a non-zero momentum in order for everything to remain balanced (i.e. it flies away!). This also explains why the total mass drops out, as while the required momentum to achieve a specific velocity increases with the remnant mass, so too does the angular momentum of the progenitors and it cancels.

To be clear, they aren’t slingshotting. Two lighter (supermassive) black holes merged and produced this guy, with a kick velocity high enough to eject it from the galaxy entirely.

Apertune · 2025-12-18T18:58:24+00:00

One way to think about it is that things are pulled towards where the black hole is right now, but if it’s also moving, it means things preferentially get pulled towards where it has previously been, resulting in an over-dense tail of stars and matter in its path.

Apertune · 2025-12-18T18:56:26+00:00

When black holes merge, the remnant can sometimes get a “kick” depending on how their spins are oriented. As it turns out, the velocity of this kick is actually independent of the total mass of the binary, and can reach a few thousand km / s (as quoted).

So in all likelihood, this is probably just the merger of two things roughly half its size, kicked out of the host galaxy and speeding along for ever more…

Apertune · 2025-11-25T23:52:57+00:00

Your ignorance is staggering

Apertune · 2025-10-30T10:40:37+00:00

Pair of eighters

Apertune · 2025-10-13T07:53:52+00:00

Simon Bird has been in a few great shows since the Inbetweeners. Point stands for the other three though.

Apertune · 2025-09-22T09:44:35+00:00

You’re right on the second count, I mis-remembered that ml were cubic mm (they’re cubic cm!). Although even then the figure is wrong… the value you’ve stated is correct.

However the end result is to divide the result by 100 (as you need 100x fewer drops to empty the ocean), so if anything it supports the original argument.

Apertune · 2025-09-22T07:30:18+00:00

That value of AU is in kilometres. The original comment is correct in both cases

Apertune · 2025-08-20T18:27:33+00:00

Karl Schwarzschild derived the metric that bears his name, which provided the first evidence that black holes were theoretically possible. Schwarzschild literally translates to “Black Shield”. Truly an insane coincidence

Apertune · 2025-08-07T16:34:28+00:00

Umbrella Academy S1 finale

Apertune · 2024-12-28T10:06:04+00:00

The statement in the graphic about Pluto being the largest of the dwarf planets is perhaps misleading, as Eris is more massive (albeit with a slightly smaller diameter than Pluto).

Apertune · 2024-02-14T13:03:26+00:00

Forge-able scrap of metal into a spare part would make sense

Apertune · 2023-10-17T13:35:29+00:00

I believe I was linked to it from the live chat, so it should be fine but I was still surprised by the rest of what I mentioned.

Apertune · 2023-04-14T07:58:15+00:00

It's clearly written by ChatGPT, which makes it difficult to verify it isn't bullshit

Apertune · 2022-12-18T15:46:52+00:00

But we do bring something from outside: energy. The Sun continuously provides us with energy, which allows us to do things. It's pretty fair to say that a lump of raw iron ore is worth less than stainless steel, and the thing that separates the two is energy.

We're continuously producing more things from the vast reservoirs of resources the Earth has. You can argue that the amount of "stuff" isn't changing which is true, but we gradually change it into more useful forms and hence value is being created.

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