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16elee t1_iv3ojgs wrote

Can someone smarter than me explain why we’re just discovering this one, even though it’s the closest? Is it because it’s much less massive than the ones we’ve already discovered?

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Bofox t1_iv3rqgu wrote

Give this a read if you’re curious!

https://www.sciencedaily.com/releases/2022/11/221104113504.htm#:~:text=hole%20to%20earth-,Gemini%20North%20telescope%20on%20Hawai'i%20reveals%20first%20dormant%2C%20stellar,hole%20in%20our%20cosmic%20backyard&text=Summary%3A,hole%20in%20the%20Milky%20Way.

Essentially, you have to be looking at the right place at the right time. We cannot detect black holes without the aid of their affects on physics around them. This one was trickier as it is dormant and therefore pretty impossible to detect. It lies in a binary system (sharing orbit with another star) so they witnessed this other star’s orbit get thrown off from a much denser object- this dormant black hole

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InGenAche t1_iv3tk61 wrote

What does 'dormant' mean in relation to black holes? Is it not actively gobbling something up right now making it dormant?

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f_d t1_iv3v5h5 wrote

They are very hard to spot when they aren't consuming anything or creating enough distortion of background objects. There could easily be closer, smaller ones.

>It was identified by observing the motion of its companion star, which orbits the black hole at about the same distance as Earth orbits the sun.

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