Are stars vanishing into their own black holes? A bizarre binary system says 'yes

It is interesting that so many stars have "gone missing" in the short period of our observations. That rate seems much higher than the rate of observed supernovas in the same volume of space. If these stars really are collapsing into black holes, it makes me wonder what the density of black holes really is in our galactic neighborhood. Could that really be the "dark matter" that we are not seeing? And, what would that mean for the probability that our solar system will eventually be disrupted by some black hole nearby that we have not yet found?
 
Nice find, nice article.

Isn't a BH the distillation/aggregation of the purest (coldest) potential energy with [most of?] the kinetic energy removed/radiated/ejected?
Usually gravitational collapsed objects, which a black hole is, radiates energy to space during collapse. But an infalling observer can't do that as soon as it has passed the event horizon since all trajectories whether for light of for infalling matter has the future time and path going "in". You have to work out another cooling scheme and also how matter is transformed to "purest ... potential energy".

Could that really be the "dark matter" that we are not seeing? And, what would that mean for the probability that our solar system will eventually be disrupted by some black hole nearby that we have not yet found?
We can observe dark matter, for example with weak lensing.

Dark matter is 5 times the mass of normal matter and it looks particular (as a "gas") rather than objects. Primordial black holes and star black holes do not show up in microlensing observations enough to explain all dark matter.

Even at the density of stars there has been little disruption during 5 billion years. "Little" as in the estimated 10 % of Earth climate effects due to "galactic noise" pulling on our orbit. Here is an assessment:
Bailer-Jones identifies the key candidates in this paper, assuming an Oort Cloud that extends to about 0.5 parsecs (1.6 light years), but he notes that a star passing even as close as several parsecs could produce significant cometary disruptions if the star were massive and slow enough. The author worked with 50,000 stars from the Hipparcos astrometric catalog in hopes of fine-tuning earlier studies of passing stars, but he notes that the search can’t be considered complete because radial velocities are not available for all stars and many are fainter than the Hipparcos work could detect. Further analysis will be needed using upcoming Gaia data.

But studying stars within a few tens of light years from the Solar System, Bailer-Jones finds forty that at some point were or will be within 6.4 light years of the Sun — the timeframe here extends from 20 million years in the past to 20 million years in the future. Fourteen stars, in fact, come within 3 light years of the Sun, with the closest encounter being with HIP 85605, which is currently about 16 light years away in the constellation of Hercules. The paper cites “…a 90% probability of [the star] coming between 0.04 and 0.20 pc” somewhere between 240,000 and 470,000 years from now, but Bailer Jones notes that this encounter has to be treated with caution because the astrometry may be incorrect. Future Gaia data should resolve this.

If HIP 85605 were to close to 0.04 parsecs of the Sun, it would be .13 light years out, or roughly 8200 AU, a close pass indeed. But one thing to keep in mind: Oort Cloud perturbation is not an unusual phenomenon, and the situation we are dealing with today is partially the result of encounters with stars that have occurred in the past.
https://www.centauri-dreams.org/2015/01/02/stars-passing-close-to-the-sun/
 

Catastrophe

"Science begets knowledge, opinion ignorance.
Question arising from post #3

Do all stars go supernova?

Supernovae add enriching elements to space clouds of dust and gas, further interstellar diversity, and produce a shock wave that compresses clouds of gas to aid new star formation. But only a select few stars become supernovae. Many stars cool in later life to end their days as white dwarfs and, later, black dwarfs.

Cat :)
 
Regrading the density of stellar mass black holes in interstellar galactic space, I don't think we yet have very good quantitative data on that just from the microlensing studies done so far. And, the large lensing effects we see from galaxies are not really distinguishable with regard to whether the mass there is in huge numbers of not-so-large discrete bodies, or gas , or swarms of "dark matter" sub-atomic particles.

But, even if not sufficient to account for all "dark matter", it seems like the rate of stars going missing is a lot higher than the rate of stars going supernova in our galaxy, so that seems to indicate a very large population of black holes in our interstellar space - IF it is the proper explanation for the missing star phenomenon.

Regarding stars that are too small to supernova that become white dwarfs, the current theory is that it would take far longer than the current theory of the age of the universe for a white dwarf to become a black dwarf by cooling sufficiently. And, I think that they could still be distinguished from brown dwarfs as they cool down, based on mass and elemental contents.
 
Could gravity waves be a means of radiating energy possibly from the other side of the event horizon?

Maybe not only interactive GWs,
but empiric GWs directly from a singular BH itself.
A shedding of wrung out space from inside the event horizon.

A transference of space from between the remnants of matter within the EH to the space outside of it.
Probably somewhat fragmentary bits of space/GWs.