There's a black hole lurking within 1,000 light years of Earth – and you can see stars circling it with the naked eye
- Reference: 1588766409
- News link: https://www.theregister.co.uk/2020/05/06/nearest_black_hole_earth/
- Source link:
A team of researchers were observing HR 6819 with the European Southern Observatory's (ESO) 2.2m MPG/ESO telescope in Chile as part of a wider survey studying binary star systems, before they stumbled across a third object. Spectrographic data revealed that one of the stars orbited an invisible companion every 40 days. Meanwhile, the second star sits much further away from the first.
They now believe that HR 6819 is not a double system, but a triple system – one that contains two stars that are both around six solar masses, and a third object that is at least 4.2 solar masses. That number is much too high for the object to be a neutron star.
Somewhere, way out there, two black holes, one large and one small, merged. And here on Earth, we detected the gravitational wave blast [1]READ MORE
"An invisible object with a mass at least four times that of the Sun can only be a black hole," said Thomas Rivinius, first author of the study [2]published [PDF] in Astronomy & Astrophysics, and an astronomer at the ESO.
"It's best visible in July, and it starts rising in the morning around this time of the year, and vanishes in the evening behind the sun around October. Right now, it's above the horizon in the morning. It's a bit on the faint side, and it's brightness would be drowned out by city lights. It's also not that far away from the bulge in the Milky Way, but to really find and identify it among its neighbours you need a chart," Rivinius told The Register .
If the researchers are, indeed, correct, the object will be the closest black hole from Earth discovered yet. "We were totally surprised when we realised that this is the first stellar system with a black hole that can be seen with the unaided eye," said Petr Hadrava, co-author of the research and Emeritus Scientist at the Academy of Sciences of the Czech Republic.
The black hole obviously isn't visible to the naked eye, only the stars are, but if you want to look anyway it's located in the Telescopium constellation in the southern hemisphere. It'll be best viewed during a clear night, and two fuzzy bright pinpricks should be discernible without binoculars or a telescope.
"One could also have a very close look, if there's really no X-ray from accretion. A little bit should be there, but it would require a fair length of observing time to detect it. This is a completely new regime of low accretion rate, and that might work differently than the high accretion rates we know of," he concluded
Although the object seems to have been near us all along, it has escaped detection until now. Not only is the black hole pretty small, it's also very quiet – meaning it doesn't spew jets of electromagnetic radiation, unlike the supermassive ones at the centres of galaxies guzzling up stars. The team has only managed to infer its existence from the wobble of the stars that orbit it.
"There must be hundreds of millions of black holes out there, but we know about only very few. Knowing what to look for should put us in a better position to find them," said Rivinius.
In fact, the team believes another system known as LB-1 might be a triple system too.
"LB-1 is a bit further away from Earth but still pretty close in astronomical terms, so that means that probably many more of these systems exist," said Marianne Heida, co-author of the paper and a postdoctoral fellow at ESO.
"By finding and studying them we can learn a lot about the formation and evolution of those rare stars that begin their lives with more than about eight times the mass of the Sun and end them in a supernova explosion that leaves behind a black hole."
Rivinius wants to get a closer look at the system to trace the orbits of the objects to get a better idea of their masses and to see whether the black hole really emits no electromagnetic energy at all.
"I'd like to take an image of the orbit. I hope we can do that with our interferometer, the VLTI. Scientifically, that would pin down the distance and masses much better," he told The Reg . ®
Sponsored: [3]Legacy Modernization: Finding Your Way With Low-Code
[1] https://www.theregister.co.uk/2020/04/21/black_hole_merger_gravitational_waves/
[2] https://www.eso.org/public/archives/releases/sciencepapers/eso2007/eso2007a.pdf
[3] https://go.theregister.co.uk/tl/1936/-8553/legacy-modernization-finding-your-way-with-low-code?td=wptl1936
southern hemisphere required
Am I safe if I'm wearing trousers around my southern hemisphere?
Re: southern hemisphere required
I'd think trousers contain a brown dwarf most of the time.
If it's a black hole, you may want to reduce your iron intake.
Interesting stuff
Might be looking for this with my telescope some time. Really intriguing target
Re: Interesting stuff
I'm not remotely surprised you had that idea!
https://en.wikipedia.org/wiki/Telescopium
Re: Interesting stuff
Lucky you if you're in south !
Geez, sometimes I wish I had taken this doctoral thesis in stellar dynamics, several decades ago ...
Back then, black holes were purely hypothetical. And today, not only do we know there's one more or less in the center of every galaxy, but also one we can observe (not directly of course) without any tooling ! Which is right next door !
As for observation, you could probably pin point the movement of the 2 stars day after day during one month, by taking a pic with a telescope each day and see the rotation around "it".
But you would need to correct it by the rotation of the 2 stars set caused by their elevation vs. the solar plane and the trajectory of earth. Looks like Euler trigonometry is in order :)
Re: Interesting stuff
I am assuming that there couldn't be nearly enough of these black holes (by a very large factor) to account for dark matter. But it does remind me of the incident in the Cyberiad when Trurl creates the machine that Klapaucius tells to do Nothing, and it does Nothing, which explains why space is so empty these days.
Starman on his way...?
I can well picture Musk's Starman in his Roadster speeding ever faster into that black hole in the (very) distant future... not a bad end, perhaps.
(Yeah, the chances are vanishingly small... BUT NOT ZERO.)
Re: Starman on his way...?
When a black hole enters our solar system, yeah, sure, Starman could go in. However, there's a far likelier chance of one of the Voyager probes taking a dive into one, since both Voyager 1 and 2 have entered interstellar space.
Side track for a mo'
Imagine light's motion is across some [unspecified] field. I compress the field by a factor of 2 and now it takes twice as long [unspecified units] to cross that field. It has twice as much of [unspecified] field to cross.
Now also suppose that light's motion and matters motion is the same, also across the field. Matter too, takes twice as long to move across that compressed field, and its dimensional size is also compressed by 2x. So when I measure the speed of light, if I'm in the same compressed field, I get the same speed of light.
Regardless of the compression factor, as long as we're in the same field as the light we're measuring, we'll get the same result for the speed of light.
OK, so now lets suppose that I'm outside the field looking into this compressed field. Now to me (at 1x compressed field), light has slowed by a factor of 2, relative to me.
i.e. compressed field = stretched space.
It might sound like I'm playing semantics here. That I'm just swapping "stretched space" for compressed field over fixed space. But space is just an arbitrary coordinate system chosen by us, if our definition of space was actually bending then it just means we screwed up our models defined in that coordinate system. If we'd defined the coordinates a different way, then space would have to bend in a different way to fixup our model. So space doesn't bend.
On the other hand, the actual field that light moves over is an actual thing. Independent of any coordinate system we choose.
To my point:
There really is no difference between the vacuum between atoms and the vacuum between planets. The speed of light through glass or through space, its the same. It ~1 local resonant wavelength per resonant oscillation, and how we measure it and perceive it changes depending on the field we're in vs the field the light is in.
So inside that black hole, is a compressed field. If it was perfect 2x compression (with no inner spinning black holes) viewed relative to our local universe, it would be perfectly dark, nothing in, nothing out and no outer spin or wobble. If you were inside it, space would appear to be normal, the speed of light would be the same, any experiment you perform outside on outside-matter would get the same result inside on inside-matter. If there are blackholes inside that blackhole, then field is even more compressed than 2x and the universe (the 'space') inside is far more stretched. The deeper the compression the larger the apparent universe to the people inside and the colder the universe appears to them.
You see how its a lot easier to think in terms of compressed resonant field wavelength than in terms of stretched space. It's a lot easier to model too if you lock your coordinate system down too.
A pic would be nice. Bouman?
Re: Side track for a mo'
And that pile of BS was meant to say what exactly?
That sounded way too much like some stoner conversations I remember from my misspent youth!
Re: Side track for a mo'
Maybe it's that fauxscienceslayer bloke back but posting as AC.
Re: Side track for a mo'
Possibly, but with any luck on his part, someone, somewhere might offer a grant. I think too many nuts and not enough fruitcakes applies.
Re: Side track for a mo'
To quote Pauli, “that’s not even wrong”
And the practical implication is......
If this thing has escaped detection up to now, and its practically parked on the bloody driveway next to the Green Waste Bin, and theres probably millions of them, then zipping across interstellar space at breakneck pace might turn out to be a bit more dangerous than we imagine.....
> zipping across interstellar space at breakneck pace
Well, there definitely isn't any black hole in our solar system, and by the time (and if!) we have the technology to send anything to the nearest star systems, I guess lurking black holes will be just a minor charting annoyance...
If this thing has escaped detection up to now, and its practically parked on the bloody driveway next to the Green Waste Bin, and theres probably millions of them, then zipping across interstellar space at breakneck pace might turn out to be a bit more dangerous than we imagine.....
As Douglas Adams said:
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."
Even if there were 1000 black holes in a 1000 light-year radius of us, that volume of space is so big and stellar-mass black holes are so small (if there were supermassive blackholes that near they would have been seen by gravitational lensing by now even if they are quiet), that you'd have more chance of finding a specific grain of sand (3-dimensional volume of beach, not just 2-d surface) on a beach than of randomly smacking into a black hole.
Dark Matter
Well, I guess we are now starting to understand where all the so called "Dark Matter" is then, since Singularities seem to be more common than previously thought. And don't worry about them "zipping around space". Anything with that mass is going to get noticed if it gets anywhere near us. 1000ly is a LONG way away!! Travelling at C it would still take it 1000 years to get here!
Re: Dark Matter
"Well, I guess we are now starting to understand where all the so called "Dark Matter" is then"
Even if this accounts for them, that wouldn't account for "dark" energy
Re: Dark Matter
Travelling at C, we wouldn’t see it coming.
1,000 light years away is a bit too far ...
for us to be able to chuck some of our more irritating politicians into it.
I'm hoping that they will spot a closer one.
Re: 1,000 light years away is a bit too far ...
We don't have to chuck them in, tossing them into the general direction is already a good start, as long as they get to LEO without oxygen.
Gravity bending light
then this could be a good candidate for some gravitation lensing
Re: Gravity bending light
Theoretically yes, in practice that particular black hole won't be heavy enough for that by a considerable margin (about a factor 100).
As Holly would say
Well the thing about a black hole, its main distinguishing feature is its black. And the thing about space, the colour of space, your basic space colour.... is its black.
So how are you supposed to see them?
Lets hope this one doesn't turn out to be grit!
Pint to the boffins for finding it before Holly.
"An invisible object with a mass at least four times that of the Sun can only be a black hole,"
Dyson sphere or other artificial stellar enclosure?
Matrioshka brain?
Impossible to us, but maybe Aliens? #historychannel #definitelyaliens
A black hole we can nearly see?
That's rather amazing. Hope some big telescope can be directed that way, in search of the accretion disc.
For boffins ->