3 ms·
Seeing that picture of a star absorbing another, I got a dumb question: Stars are balls of glowing plasma. If you were to vacuum it, as another star or black h
by sph 3y ago
Seeing that picture of a star absorbing another, I got a dumb question:
Stars are balls of glowing plasma. If you were to vacuum it, as another star or black hole too close for comfort would, what would this plasma look like? I reckon it would not be visible, a bit like trying to vacuum fire. All you get is hot, invisible gas.
So effectively, the image at the top of the article is completely unrealistic. Any transfer of matter from a star would be basically invisible to the naked eye. You'd see two stars close by, and one getting imperceptibly smaller than the other that slowly grows.
Is that correct?
- londons_explore 3y agoI wouldn't recommend trying to vacuum fire... But if you were to do it, you would find you ended up with flames going all the way up your vacuum hose and into the dust collector. So from that perspective, fire is very much vacuumable.
- sph 3y agoFair enough, because it didn't have time to cool down yet. But at astronomical scales, even if vacuum is a good insulator, the glowing plasma would somewhat cool down before it reaches the other star, I imagine.
- danparsonson 3y agoThere are no dumb questions, only dumb answers - so here goes: Hot things emit light. The wavelength(s) of light a substance emits depends on the temperature of that substance - cooler things emit longer (redder) wavelengths, hotter things are bluer. If the substance is cool enough, the light emitted will be mostly or wholly infra-red, therefore invisible to the naked eye but still detectable. The top of a flame is like that - the gas is still hot but no longer glowing visibly as it cools. Therefore the answer to your question depends on how hot the plasma is, but a confounding factor is that the hoovering object would create friction in the incoming material, thereby heating it up. I think the corona of a star glows with its own light (not just light emitted by the core), so I expect therefore that you would see a lot of light overall, especially nearer to whatever is doing the vacuuming.
- sph 3y agoThanks for the great answer! I didn't think of friction. We recently got a picture of our first blackhole, time to snap a picture of a star or a blackhole slurping another star. Would be quite a sight. My Google-fu only returns artists renditions.
- danparsonson 3y agoWhat I wouldn't give to see such a thing :-)