Closest and Smallest Black Hole Known Discovered

[Drashner1]

A black hole only 1500ly away and 3x as massive as Sol - LINK

[stevebowers]

I'm not too keen on the image accompanying that article. If we were to include this in OA I'd use something like this

[Drashner1]

Agreed, your image is much nicer and probably much more realistic.

Is this one of yours or pulled from somewhere? And if it is one of yours, did you already have it 'on the shelf' and just posted it or did you see my post and create this all in less than 7hrs (and overnight in England, if I have my time zones right)? Just curious.

Speaking more broadly, this system is deep in Terragen space by Y11k and might be expected to be heavily developed in some fashion (barring some strong reason for it not to be). I thought about retconning the EG to make this the Threshold BH, but that seems to be a solitary BH rather than a binary and certainly there is room for multiple natural BHs in the setting. So probably best to make this something new.

Thoughts on what we might do with it? The only other idea I've had so far is to install a Binerator (which we list in the EG but don't do anything with in the setting)? Although conversion tech and such may render such a thing to the level of a solar heated shower or the like.

Do we know which empire this system would be in in Y11k?

Todd

[stevebowers]

I made it this morning. I was up early waiting for a tradesman to call, so I thought I'd made a better image for this system while I was waiting.

The black hole itself would be invisibly small at this scale, and I think I've made the distorted region around it a bit large. But it works as a first approximation.

[stevebowers]

It's in Monoceros, so should be in the Orion Federation.

[selden]

Preprints are at https://arxiv.org/abs/2101.02212 (original)
and https://arxiv.org/abs/2103.05216 (tidal effects)

Note, however, that it does not have the accretion disk that Steve drew. That’s one of its surprising characteristics.

[selden]

A slightly larger (3.3 solar masses vs 3 solar masses) black hole in a similar binary has been described in https://ui.adsabs.harvard.edu/abs/2019Sc...T/abstract and https://arxiv.org/abs/1806.02751

It seems to be about 3kpc away, though, currently outside the Terragen sphere.

Eta: both of these are classified as non-interacting black holes (I.e. no accretion disk), of which about 1,000 are estimated to be detectable by Gaia. So I’d guess maybe a dozen might be in the Terragen sphere.

[stevebowers]

I'll use this image for a different black hole binary. Or perhaps V723 will start accreting by the time Terragens get there, probably sometime in the Early ComEmp period.

The lack of an accretion disk would make the V723 black hole itself difficult to see, unless we use forced perspective.

[selden]

Yes, that would be a challenge, I think. Especially if it were showing a transit.

[Bear]

I think it doesn't require an accretion disc. Visibly, it's going to be an egg-shaped star with its narrow end pointing toward a very small chunk of the starfield that has a noticeable fisheye-lens effect, where stars are seen as short arcs centered on the singularity that's bending the light before it reaches the observer. And that, I think, is enough to show. Look at Scott Manley's wormhole images for a good idea of what a black hole without accretion disc looks like.

In the context of OA, however, I think it would be regarded as an opportunity to do some particularly cheap, easy, efficient starlifting. What you have here is a star subject to intense tidal effects that keep its plasma continually on the verge of escaping anyway; it's not hard to imagine people (most likely radiation-hardened vecs or AI, not biologicals) getting there and noticing that an occasional pulse of electromagnetic energy at a moment when it creates constructive interference with turbulence propagating through the corona of the star, gets them many times the starlifting mass output that would normally be available from such a paltry contribution of energy.

So it's.... what, 1500LY? So, someplace that, in-story, people would reach about 3K years from now? At that date I don't think it's going to be the very first starlifting project, but it would certainly be notable as the first highly-efficient starlifting project taking advantage of tidal energy generated by a black hole.