3 ms·

I'm not sure I understand the significance. Is it observation of something we'd expect anyway or something more. All stars in the galaxy are orbiting a superma

I'm not sure I understand the significance. Is it observation of something we'd expect anyway or something more. All stars in the galaxy are orbiting a supermassive black hole at the center. So this is similar but on a much smaller scale. Maybe the find is illuminating early black hole interaction with nearby stars, idk.

ISL 4y ago
Unless I'm now out-of-date, it is the first time a system quite like this has been observed. Quiet star quietly orbiting in a black-hole binary. Furthermore, it is very close to us on cosmological scales -- in our own galaxy, just over 1% of a galactic-diameter distant. From this observation alone, one can directly sharpen up models not only of the probable number of BH-star binaries in the galaxy, but also models of the number of lonely black holes in the galaxy. Forty years ago, this might have been a Nobel-winning discovery, as it would have provided new and compelling evidence for the existence of black holes (the dark partner can't be a neutron star because it is far too heavy). That story is now familiar to astrophysicists from many angles. This discovery is still one of the early remarkable results from Gaia -- that dataset is going to continue to shape our understanding of our neighborhood and our universe for decades to come. It's very cool.
sulam 4y ago
It’s not a typical binary. The money quote is 2/3 of the way down, essentially saying this is a bog standard G-type star with no obvious means to end up in this configuration that doesn’t involve complex interactions, up to and including a black hole wandering by and capturing the star (and probably sending all its planets spinning off into the universe). Your typical binary like this is in close orbit, with far higher radial velocities (ie they are spinning like a top), and they show the effects of having been within shooting distance of the creation of their special friend (ie they got fried in a supernova).
pohl 4y ago
The title does bury the lede: this discovery is the closest confirmed black hole now. Before that, the closest was ~3000ly away. There might be one ~960ly away, but that hasn't been confirmed. https://en.wikipedia.org/wiki/List_of_nearest_known_black_holes https://en.wikipedia.org/wiki/List_of_nearest_known_black_ho...

ISL 4y ago

Unless I'm now out-of-date, it is the first time a system quite like this has been observed. Quiet star quietly orbiting in a black-hole binary. Furthermore, it is very close to us on cosmological scales -- in our own galaxy, just over 1% of a galactic-diameter distant. From this observation alone, one can directly sharpen up models not only of the probable number of BH-star binaries in the galaxy, but also models of the number of lonely black holes in the galaxy. Forty years ago, this might have been a Nobel-winning discovery, as it would have provided new and compelling evidence for the existence of black holes (the dark partner can't be a neutron star because it is far too heavy). That story is now familiar to astrophysicists from many angles. This discovery is still one of the early remarkable results from Gaia -- that dataset is going to continue to shape our understanding of our neighborhood and our universe for decades to come. It's very cool.

sulam 4y ago

It’s not a typical binary. The money quote is 2/3 of the way down, essentially saying this is a bog standard G-type star with no obvious means to end up in this configuration that doesn’t involve complex interactions, up to and including a black hole wandering by and capturing the star (and probably sending all its planets spinning off into the universe). Your typical binary like this is in close orbit, with far higher radial velocities (ie they are spinning like a top), and they show the effects of having been within shooting distance of the creation of their special friend (ie they got fried in a supernova).

pohl 4y ago

The title does bury the lede: this discovery is the closest confirmed black hole now. Before that, the closest was ~3000ly away. There might be one ~960ly away, but that hasn't been confirmed. https://en.wikipedia.org/wiki/List_of_nearest_known_black_holes https://en.wikipedia.org/wiki/List_of_nearest_known_black_ho...