Stellar Black Hole question

[Jak Nazryth]

Question to the physicists and part time astronomers in the Travellerverse...
By now it's accepted theory that super-massive black holes are at the center of most galaxies. But what about Stellar Black Holes? How common are they? Have any been discovered in one of the spiral arms or our galaxy? How disruptive would they be to the local arm? (Orion spur)
I've had an idea since the early 80's of having a black hole as a plot hook in my Traveller games. The issue of course is that it's not cannon in the least, and I'm not sure how destructive it would be. My idea is locating it inside the rift.. (maybe the reason there is a lack of stars)? The plot hook idea is that a 3I Science station is orbiting the SBH at a safe distance with plenty of ideas for plots and adventure scenarios. The SBH is not going to "gobble up" the Traveller Map.. not within the next several million years at least.
Anyway. Just a question.
Is it a feasible idea to introduce a SBH within the Traveller "area" of our galaxy?
Or is it just a silly "Hollywood" idea?
Thanks.

 

[dragoner]

Timely post, National Geographic's current issue is on black holes; from the article I seem to remember two main points: 1) We don't really know what they are, and 2) they seem to be more common than originally thought. So there can be one in charted space, maybe more.

 

[Wil Mireu]

Question to the physicists and part time astronomers in the Travellerverse...
By now it's accepted theory that super-massive black holes are at the center of most galaxies. But what about Stellar Black Holes? How common are they? Have any been discovered in one of the spiral arms or our galaxy? How disruptive would they be to the local arm? (Orion spur)

Black holes only form when the most massive stars explode as supernovae (over about 8 solar masses I think). Those stars are pretty rare (at most 0.05% of all stars (from http://en.wikipedia.org/wiki/Stellar_classification ), so 1 in 2000 stars?) so black holes must be at least that rare.

The nearest black hole to Sol appears to be V404 Cygni ( http://en.wikipedia.org/wiki/V404_Cygni ) which is 7800 lightyears away. There'd probably only be one or two in all of Charted Space at most.

The supernova that formed them would have sterilised any systems within a few dozen parsecs of them so they'd be disruptive in that sense.

 

[ShawnDriscoll]

But what about Stellar Black Holes? How common are they?

About as a common as gamma ray bursts. I'd worry more about the bursts than the black hole left behind. Traveller ships don't get to see much of the galaxy. So there is little chance for them to encounter a black hole.

 

[Jak Nazryth]

Laughing Out Loud. :lol:
Speak of the Devil. :shock:
How cool is this! 8)
I'm relocating the Kinunir adventure from Regina to the Trojan Reach just across the border of the Spinward Marches. There are 3 asteroid fields in the area (distributed withing Pax Rulin and Gazulin) that will do nicely for the Kinunir's resting place. Since this part of the Imperial Borders are lined with Naval stations to combat pirate and Aslan incursion, it makes a great replacement setting for the Kinunir disappearance some 30 years ago after fighting of an incursion.
While looking at my map, I noticed that one asteroid belt (627-301) had the symbol for a research lab, and is a red-zone system. Peaking my curiosity, turned to the subsection write-up, 627-301 of Alien Module 1: Aslan; and it actually has a paragraph describing belt 627-301, much to my surprise! Here is the quote:
"This highly restricted system is a mystery to the Imperium. The gravitational center of 627-301 is not the main star; it is a tiny black hole that the sun orbits around. The research station orbits a gas giant that orbits the star. Computer projections show that this arrangement is not stable and that the star with be destroyed within half a million years. The black hole is believed by some to be artificial but other theorize that the singularity "collected" the system as it traveled through space."

What do you know. Just the exact thing I was looking for. AND IT'S CANNON!

 

[JRoss]

Biggest thing to remember with a BH is that they are not, NOT, NOT these all-consuming sink-holes in space. They don't cause the galaxy to drain into them like water leaving the bath tub. Having gone supernova they have less mass than they did as a star (or about the same if they've pulled in their ejecta).

If you were to fly too close to the sun then you would get "sucked in," just like you would get "sucked in" to a black hole if you got too close. It's likely that you would detect them, or the radiation that they emit.

 

[Condottiere]

Perpetual motion machine, or long enough, if you can figure some way to rope in physics to power up whatever kinetic flywheel that is close enough to be effected, but far enough away not to get swallowed.

 

[Tom Kalbfus]

Question to the physicists and part time astronomers in the Travellerverse...
By now it's accepted theory that super-massive black holes are at the center of most galaxies. But what about Stellar Black Holes? How common are they? Have any been discovered in one of the spiral arms or our galaxy? How disruptive would they be to the local arm? (Orion spur)

Black holes only form when the most massive stars explode as supernovae (over about 8 solar masses I think). Those stars are pretty rare (at most 0.05% of all stars (from http://en.wikipedia.org/wiki/Stellar_classification ), so 1 in 2000 stars?) so black holes must be at least that rare.

The nearest black hole to Sol appears to be V404 Cygni ( http://en.wikipedia.org/wiki/V404_Cygni ) which is 7800 lightyears away. There'd probably only be one or two in all of Charted Space at most.

The supernova that formed them would have sterilised any systems within a few dozen parsecs of them so they'd be disruptive in that sense.

Actually one reason supermassive stars are so rare is because they are short lived, a type O star has a lifespan of about a million years or so, while more ordinary stars like our Sun last billions of years, the black holes created by an imploding supermassive star lasts much longer than the star that created it, so I would expect a stellar black hole to be about 1000 times more common. So according to the above example there might be 1 black hole for every two stars.

Of course a lot of black holes can't be seen because they have no visible companions and no in falling matter. Without in falling matter, the black holes would admit no x rays, but since space is rarely completely empty, there will always be some x-ray emissions coming from a black hole, which would make those black holes detectable at close range, but perhaps not at a distance of parsecs.

The point is a black hole can last longer than the current estimated lifetime of the Universe, the only way they die is from Hawking radiation, which for a stellar mass black hole is very slow! So a supermassive star lasts for a few million years, while the black hole they create persist far longer. They are not as rare as you think, because once created, a black hole is very difficult to destroy!

I would expect a black hole to be rarer than a white dwarf and rarer than a neutron star, but not much more so Lets say their rarity is in proportion to the stars that created them modified by the star's life times. There may also be many more neutron stars than you think, the ones we can detect are called pulsars, because they spin very fast, but the ones that spin more slowly may be harder to detect.