Astronomers discover black hole closer to Earth than any before

[glenc]

The black hole is tiny, only 40km in diameter
It is not close enough to swallow anything, but it is warping the orbit of its nearest star
Scientists estimate the black hole was violently born from a supernova 15 million years ago
The new black hole is part of what used to be a three-star dance in a system called HR6819.
The star QV Tel is magnitude 5.37 and 1120 light years away
Studies using the 2.2m telescope at La Silla Observatory in Chile reveal the inner of the two visible stars to be orbiting an unseen object every 40 days.
Presumed to be a black hole, this object has a likely mass of at least four times that or our Sun.

https://www.abc.net.au/news/2020-05-07/astronomers-discover-closest-black-hole-to-earth-ever/12222154

[pfitzgerald]

Thanks for sharing this Glen - I'll pass it on to the students in my School's Astronomy Club.

Paul

[Robh]

Fascinating! Thanks Glen.
Especially the prospect of these being quite common. That would add a bit more mass to the galaxy.

The naked-eye star QV Tel must be a very tight pair. The WDS catalogue doesn't have any components listed for it.

Regards, Rob

[glenc]

Wiki has just updated their entry for QV Tel to include the black hole
https://en.wikipedia.org/wiki/QV_Telescopii

[gary]

The ESO press release here with additional detail :-
https://www.eso.org/public/news/eso2007/

The research paper, "A naked-eye triple system with a nonaccreting black hole in the inner binary", by Rivinius et. al. :-
https://www.eso.org/public/archives/releases/sciencepapers/eso2007/eso2007a.pdf

[cannon_gray]

The discovery of this black hole will help scientists find other similar objects in the Milky Way that do not interact with the external environment and therefore have not yet been noticed. Probably, some of them maybe even closer to the solar system.

[Rob_K]

Not cut-&-dried:
https://www.sciencealert.com/the-closest-black-hole-to-earth-has-been-reidentified-as-a-very-special-pair-of-stars

Cheers -

[Stonius]

I wonder what was happening in the sky in the year 901 CE. I'm assuming this must have been visible?