Blackhole/Star Binary System

[All Seeing Eye]

Is it at all possible for our Sun to be part of a binary system with the other body being a blackhole and not another star?

If so, would the said blackhole be undetectable to us?

If not undetectable what would we be able to detect about it?

Would it be possible for the blackhole to approach close to our sun but only affect it minimally with it's gravitational effect?

 

[Jadzia]

If not undetectable what would we be able to detect about it?

Gravitational lensing of our view of background space. And it's gravitational effect on our sun and planets.

Would it be possible for the blackhole to approach close to our sun but only affect it minimally with it's gravitational effect?

It's a question of relative distance from the planets to the two stars, and how frequently the companion star/black hole makes its approach.

If a companion star/black hole had strongly elliptical orbit, the planets and asteroid belts would not be as stable as they are. They would have been thrown into all sorts of weird trajectories, where chaos would ensue.

The fact that the planets mostly have very close to circular orbits suggests that there is only one massive body nearby: the sun.

 

[All Seeing Eye]

If not undetectable what would we be able to detect about it?

Gravitational lensing of our view of background space. And it's gravitational effect on our sun and planets.

Would it require sophisticated telescopes to view or could any tom, dick and harry see it through an amateur telescope?

 

[Lindley]

Depends on the size. Most black holes of any notable mass have a visible accretion disc.

 

[Robert Maxwell]

It's worth noting that Pluto was discovered partially because there were unexplained perturbations detected in Neptune's orbit. In other words, we can detect the presence of relatively small masses in our solar system by how they affect nearby bodies.

There is no way there could be a black hole in our solar system and us not know about it by now.

 

[kkozoriz1]

Actually, when Voyager 2 flew past Neptune it enables a more accurate measurement of the planets' mass. This gave a more accurate desciption of it's orbit. There were no measurable elements caused by Pluto. Pluto just happened to be where the inaccurate calculations said a planet could be.

 

[Goliath]

^Yes. It's an interesting case of a false anomaly leading to a true discovery. It's comparable to Copernicus adopting a heliocentric model of the universe, because everybody knew that the planets moved in circles at constant speeds.

Anyway, Robert Maxwell was right on the important point: namely, that if there was a black hole in our solar system, we would have detected it long ago, from the gravitational influence it was exerting on everything else.

 

[Robert Maxwell]

Actually, when Voyager 2 flew past Neptune it enables a more accurate measurement of the planets' mass. This gave a more accurate desciption of it's orbit. There were no measurable elements caused by Pluto. Pluto just happened to be where the inaccurate calculations said a planet could be.

Really? I didn't know that. Guess I learned something today!

 

[Christopher]

Depends on the size. Most black holes of any notable mass have a visible accretion disc.

That's a common misconception perpetuated by Hollywood. A black hole would only have an accretion disk if there were material nearby for it to draw in, as for instance if it were a close binary companion of a star or were a supermassive black hole in the cluttered center of a galaxy. The standard Hollywood depiction of a standalone BH in the middle of empty space -- stress empty -- having a huge glowy whirlpool of infalling matter around it is a huge contradiction.

A standalone black hole would most likely be "dormant," as it's called -- i.e. it wouldn't have anything falling into it and producing detectable heat, light, and radiation. It would just be a black hole, a pucker in spacetime that could only be detected by its gravitational lensing of background stars and its gravitational effect on the orbit of other bodies.

There is no way there could be a black hole in our solar system and us not know about it by now.

Very unlikely, true. However, there is evidence of something causing perturbations of comets in the Oort Cloud, and there's a distinct possibility that there may be an undetected Jovian planet or brown dwarf out there.

 

[knine]

It's worth noting that Pluto was discovered partially because there were unexplained perturbations detected in Neptune's orbit. In other words, we can detect the presence of relatively small masses in our solar system by how they affect nearby bodies.

No, NEPTUNE was discovered due to REAL unexplained perturbations in the orbit of URANUS. Although Neptune was actually bright enough to be observed in telescopes before astronomers realized it was a planet.

The discovery of Pluto was essentially dumb luck because some astronomers wanted to believe their so-called perturbations in Neptune's orbit so badly that they launched a huge observation campaign and eventually found something moving in the sky. They wanted to be famous like Le Verrier and Adams who both basically discovered Neptune on paper before observations showed it was a planet.

This isn't the first time astronomers decided what they were going to find before they actually looked for it and then turned out to be wrong.

Part of being a good scientist is to NOT decide what the answer is going to be before the experiment and then forcing your data to fit your bias.

 

[Robert Maxwell]

Yes, I stand corrected.