Supernova shoots a dying star made of metal out of Milky Way at 2M MPH

techradar.com

42 points·wglb··9 comments

Note: this is the Astronomy definition of metal... There's Hydrogen, Helium and then there's metals.

Why is this definition useful in astronomy? Why can't they just say something like "non period 1 element" (NPO element) in order not to cause accidental confusion with other branches of science?

Just that by volume/mass hydrogen and helium make like 99% of what's out there :)

Good question. It's all about context, which I don't know that well. But these kind of things pop up everywhere. https://en.wikipedia.org/wiki/Engineering_tolerance

Some info on the word metal as used in astronomy:

https://briankoberlein.com/post/hydrogen-helium-metal/

The short answer is that the fraction of metal is so low, they don't care enough to call it something else.

So I wonder if there is a black hole or neutron star headed the other way at 2M MPH.

It's a slightly terrifying thought that such objects could exist.

Is a neutron star on a collision course with you at 560 mi/s more terrifying than one approaching at, say, 10 mi/s?

For those wondering, this is 1/335th of the speed of light. Generally relativistic effects start being significant at around 10% speed of light, so no significant relativistic effects from this, I think.

Yeet!

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