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A Black Hole System Visible to the Naked Eye

05/08/2020 1:05 PM

Recently, a triple system containing a black hole has been discovered about 1000 lightyears away, visible to the naked eye from the southern hemisphere.

"A team of astronomers from the European Southern Observatory (ESO) and other institutes has discovered a black hole lying just 1000 light-years from Earth. The black hole is closer to our Solar System than any other found to date and forms part of a triple system that can be seen with the naked eye. The team found evidence for the invisible object by tracking its two companion stars using the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. They say this system could just be the tip of the iceberg, as many more similar black holes could be found in the future."

https://www.sciencedaily.com/releases/2020/05/200506091537.htm

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#1

Re: A black hole system visible to the naked eye

05/08/2020 1:44 PM

I agree that this is probably the first of many "neighborhood" black holes to be discovered. I wonder how much these added masses will contribute to the missing mass paradox of dark matter. My WAG is this may eventually account for 10% of the missing mass, but that is nothing more than my Wild A$$ Guess.

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#2

Re: A black hole system visible to the naked eye

05/08/2020 2:11 PM

since it’s been reported, or more accurately, ‘stated’ that all galaxies have a supermassive black hole in the center of it, and this black hole being only a thousand light years away... that’s getting too close.

its interesting that this black hole doesn’t interact as violently with its surrounding environment as other black holes do... that’s interesting enough...

oh, and by the way... your title on this thread is misleading.

yes, I know it was a take from the research paper called.... "A naked-eye triple system with a nonaccreting black hole in the inner binary,"

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#3
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Re: A black hole system visible to the naked eye

05/08/2020 2:51 PM

I was driving down the road one day when I read a bumper sticker on an Astro van with a big telescope in the back.

It read. "If you can see my black hole? you're driving too close"

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#4
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Re: A black hole system visible to the naked eye

05/08/2020 3:59 PM

Lol...

Oh,... we’re talking about that kinda black hole... say,... have I ever introduced you to my pet one eyed monster?...

His name is ‘One Eyed Wille’...

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#5
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Re: A black hole system visible to the naked eye

05/08/2020 4:22 PM

Oh I know that guy. My dog goes and whispers something to him when I take him out on walks

Then they read each other's pee mail and we're on our way.

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#17
In reply to #5

Re: A black hole system visible to the naked eye

05/09/2020 8:06 PM

Are you saying my pet is actually a dog? And all this time I took him for a walk, he’s been walking backwards....

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#6
In reply to #4

Re: A black hole system visible to the naked eye

05/08/2020 10:58 PM

Whoa! What is that dogs affiliation?

Dogs seem to display symbols aligned with more traditional values around here.

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#10
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Re: A black hole system visible to the naked eye

05/09/2020 1:29 PM

This thread has certainly taken a sad, distasteful turn. I guess astrophysics are the new taboo topic on CR4.

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#12
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Re: A black hole system visible to the naked eye

05/09/2020 3:39 PM

"A person reveals his character by nothing so clearly as the joke he resents." -G.C. Lichtenburg

Why let a stern outlook spoil the enjoyment of the chaos in the carnival of life. Refusal to let yourself enjoy a stupid joke doesn't make you smart, just a wet rag.

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#13
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Re: A black hole system visible to the naked eye

05/09/2020 4:18 PM

I like the quote and accept the rebuke.

I was just hoping for a few more replies related to the original topic, particularly when one doesn't mark a reply as off-topic. You are correct though, what's the point of being polite when administrators wield crude cudgels they think are funny.

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#16
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Re: A black hole system visible to the naked eye

05/09/2020 8:04 PM

You’re still upset because I couldn’t read your mind on what you really wanted to talk that had nothing to do with the topic on another thread,... it put you in a twist so much, that you had to send me that vile PM.

And now your complaining, that shows your true character.

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#22
In reply to #16

Re: A black hole system visible to the naked eye

05/10/2020 9:29 AM

So you admit to trolling me. You are so sad. You are so pathetic.

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#23
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Re: A black hole system visible to the naked eye

05/10/2020 3:36 PM

Trolling?,... How’s that?... You must think of yourself way too highly of yourself ,... come back down to earth,...

tissue?,... again

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#30
In reply to #13

Re: A black hole system visible to the naked eye

05/11/2020 4:02 AM

Kudos for such a healthy response to a rather personal criticism. i respect that

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#7
In reply to #4

Re: A black hole system visible to the naked eye

05/09/2020 12:51 AM

How old is he?

I couldn't really tell by looking up his date.

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#8
In reply to #4

Re: A black hole system visible to the naked eye

05/09/2020 5:43 AM

Phoenix #4 - your pic takes me to the story of the chap who invented the 'cats-eye' reflector.

He got the idea from the reflection of his car headlights from a cat facing him in the road one night.

Apparently, but lesser known, the driver of the car coming towards him invented the pencil sharpener

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#18
In reply to #8

Re: A black hole system visible to the naked eye

05/09/2020 8:16 PM

Are you pulling my leg, or was that a true coincidental happenstance between those two people.

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#15
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Re: A black hole system visible to the naked eye

05/09/2020 5:23 PM

We're perfectly safe at 1000 light years. The black hole has a mass of about 4 times the sun's mass. There are plenty of stars that big.

If there's no material being accreted, the hole will be invisible. Another star is in orbit with the black hole, moving in an ellipse about every 40 days about an unseen companion (the black hole).

The masses of orbiting stars can be determined. A mass of 4 solar masses is too much for a neutron star (Chandrasekhar limit).

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#34
In reply to #15

Re: A black hole system visible to the naked eye

05/11/2020 11:32 PM

But how do we know we are safe, from other black holes?

The fact this one was interacting is the only reason it was discovered, how many are out there away from other stars hooning through space looking for a tasty meal of a suitably sized solar system.

Similarly engaging warp drive to travel through the "empty" tracts of space is likely to result in a black hole burp as you stretch into a thin ribbon and then come to an abrupt halt in the centre of the truly invisible enemy.

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#36
In reply to #34

Re: A black hole system visible to the naked eye

05/15/2020 6:21 AM

"... But how do we know we are safe ...."

.

We don't and we can't. Who suggested such an expectation?

.

"... Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure, or nothing. ..." -Helen Keller.

.

"

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#9

Re: A Black Hole System Visible to the Naked Eye

05/09/2020 1:24 PM

Since this is a small "non-accreting" black hole, will it and others like it, someday suffer the fate of Pluto. That is, be declared by minds far more accredited than mine not a black hole, but rather a pseudo, dwarf or some other diminishing terminology that relegates it to the not-really-one class of black hole.

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#11
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Re: A Black Hole System Visible to the Naked Eye

05/09/2020 1:44 PM

I doubt these black holes will become reclassified for this type of a black hole has been expected to exist for a long time.

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#14
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Re: A Black Hole System Visible to the Naked Eye

05/09/2020 5:06 PM

I might agree with you but for one simple truth. When Pluto was found by Tombaugh in 1930 his search was driven by a common near-earth astronomical premise. Existing planetary observations in the late 19th Century of predicted vs observed planetary rotational paths predicted the ninth planet. Only after more than a 1/2 century after discovery was it downgraded by an entirely different set of experts. In the 21st Century +60 years qualifies for an internal long time.

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#20
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Re: A Black Hole System Visible to the Naked Eye

05/09/2020 9:34 PM

Neptune was discovered by analyzing the orbital perturbations of Uranus. Pluto was "discovered" the same way, by analyzing Neptune's orbit. The original estimate was the mass would be 7 times earth's mass, but Pluto was just discovered by mistake. Its mass is far too low to perturb the massive gas giants. They're still looking for "Planet 9".

Mass estimates for Pluto
YearMassEstimate by
19157 Earth

Lowell (prediction for Planet X)[15]

19311 Earth

Nicholson & Mayall[36][37][38]

19480.1 (1/10) Earth

Kuiper[39]

19760.01 (1/100) Earth

Cruikshank, Pilcher, & Morrison[40]

19780.0015 (1/650) Earth

Christy & Harrington[41]

20060.00218 (1/459) Earth

Buie et al.[42]

https://en.wikipedia.org/wiki/Pluto

As for black holes, I think it unlikely that stellar black holes will ever be considered "non-blackholes". A black hole has a specific definition. It forms when matter becomes dense enough that the gravitational escape velocity reaches the speed of light.

https://en.wikipedia.org/wiki/Black_hole

Planets, on the other hand, are in the eye of the beholder. A sentient species living on Jupiter might well argue the solar system has 4 planets, with the 4 rocks closest to the sun to be insignificant.

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#19
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Re: A Black Hole System Visible to the Naked Eye

05/09/2020 8:19 PM

That’s a good point, considering this black hole doesn’t react as violently as other black holes do,... as I say before, that interesting enough.

I don’t know what types of classifications black holes currently have... I only know of black holes and super massive black holes.

and if more classifications are developed,... wasn’t Pluto’s reclassification came from a consensus of scientists?, would that be the same for black holes?

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#21
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Re: A Black Hole System Visible to the Naked Eye

05/09/2020 10:40 PM

The reclassification thing is endemic throughout the sciences. In wildlife biology for many genus species differentiation has come down to genetic differences barely greater than human racial differences. Personally I believe fine tooth coming does little to advance science, it does however greatly advance scientists' careers. As for the Pluto consensus it was achieved amongst a limited minority group. The vast majority of astrophysicists and astrophysical (non-PhD) professionals were not party to the decision.

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#24
In reply to #21

Re: A Black Hole System Visible to the Naked Eye

05/10/2020 3:43 PM

Thanks,...

A couple of things here...

1.) The vast majority of astrophysicists and astrophysical (non-PhD) professionals were not party to the decision.

that doesn’t seem right.

2.) what I mentioned before that was in the OP link, that this black Hole is not acting as violently as other do. To myself, a layman on this matter, to classify something, should they be at least a somewhat understanding on the physical aspect of this black hole on the reasons why it’s not acting as violently to its environment.

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#25
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Re: A Black Hole System Visible to the Naked Eye

05/10/2020 4:29 PM

1.) The vast majority of astrophysicists and astrophysical (non-PhD) professionals were not party to the decision.

that doesn’t seem right.

Welcome to the modern world where the self-appointed make the decisions. For a change this important you would think a polling or such would take place. You would be wrong. Down here in NASA country where astrophysics is a profession more common than most places input was not sought nor particularly appreciated when given. When the daily practitioners of our solar system are shut out you can assume numerous more we're also.

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#26
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Re: A Black Hole System Visible to the Naked Eye

05/10/2020 5:01 PM

It all depends on how one defines an astrophysicist professional. Brian May has a PhD in astrophysics but I doubt he was consulted on the question of how to define a planet. There is also the simple logistic problem of how many different voices should be heard on this decision. It can be easier to herd cats than to get a group of scientists to decide how to define anything, let alone something that all people have touched only one of.

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#29
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Re: A Black Hole System Visible to the Naked Eye

05/10/2020 7:42 PM

Agreed on many fronts, but when professionals who deal with the scientific understanding of a particular subject and have the most practical knowledge of that subject are cut out of the naming loop than that's an issue.

About scientific naming; it seems to be fraught with interesting values. There is a North American bat, commonly called the Mexican Freetailed Bat, here in Texas that solely winters in Mexico and summers in the southern 1/2 of Texas for breeding. This said, the genera species name directly translates to Brazilian bat. Why name a creature that is only found on a different continent in a different hemisphere after a place nowhere near it's natural occurrence? I surely don't know, but I'm pretty damn sure the name has nothing to do with the creature's scientific reality.

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#28
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Re: A Black Hole System Visible to the Naked Eye

05/10/2020 7:33 PM

Thanks,

Thats true and would be in any industry,

in packaging as an example, there are people who drive to be front and center of all media photo ops or stories, touting how great they are,... until you look at their wake on what got them there that’s strung with bodies and careers they broke and left in their wake to get to the top.

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#31
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Re: A Black Hole System Visible to the Naked Eye

05/11/2020 7:03 AM

"... understanding on the physical aspect of this black hole on the reasons why it’s not acting as violently to its environment. ..."

It is unlikely that this black hole is significantly different from most other black holes. It isn't likely to be behaving any differently to its particular surroundings than any other black hole of similar spin, charge and mass would.

The surroundings of this particular black hole just don't have a significant amount of mass close enough be accreted during the time period we are viewing.

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#27

Re: A Black Hole System Visible to the Naked Eye

05/10/2020 5:06 PM
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#32

Re: A Black Hole System Visible to the Naked Eye

05/11/2020 7:47 AM

Now that they identified the location of this black hole I wonder if they can also observe any gravitational lensing effect at that location on the celestial sphere. With such a relatively small amount of mass (>4 Suns) I don't expect a significant deflection but it still would be interesting to know if anybody is looking for this.

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#33
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Re: A Black Hole System Visible to the Naked Eye

05/11/2020 6:37 PM

Seems like that would depend on whether or not there are any objects sufficiently luminous in the background (from our perspective) that might otherwise be eclipsed by an object the diameter of the black hole's event horizon traveling over its orbital path.

The Schwarzschild radius for 4 solar masses is a little over 7 miles. So that's a 14 mile width over however long the orbital path appears from our perspective.

At 1000 light years 14 miles is incredibly thin. It subtends an angle of only around 4×10-17 of a degree. Even if the orbit were exceptionally large, that is going to be a miniscule area of the sky.

If we are fortunate enough to have something bright enough in the background, it will still be remarkable to be able to discern lensing from that small area it eclipses from 1000 light years away.

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#35
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Re: A Black Hole System Visible to the Naked Eye

05/13/2020 2:05 PM

The Schwarzschild radius defines the size of the event horizon for a black hole, not the limit where light bends at all. Our Sun has no Schwarzshild radius, by definition only one solar mass and still produces a measurable bending of light during a solar eclipse. This is precisely how Einstein's prediction of gravity warping space even for light paths just over a century ago. Certainly the eight minutes and twenty seconds of light time between Earth and Sol is a lot closer than the one thousand years of light time between Earth and this black hole. The level of angular resolution for observing gravity lens effects is still phenomenal.

From the Wikipedia page on Gravitational lens

Here is a useful animation from the same page.

A light source passes behind a gravitational lens (point mass placed in the center of the image). The aqua circle is the light source as it would be seen if there were no lens, while white spots are the multiple images of the source (see Einstein ring).

Since the lensed objects are behind the gravity well lens, locating a known black hole only a thousand light years away should make this an interesting region to keep looking.

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#37
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Re: A Black Hole System Visible to the Naked Eye

05/15/2020 6:40 AM

Of course the sun has a Schwarzschild radius. Any mass does. The Schwarzschild radius of the sun is a little under 3 kilometers, so not within our view.

.

You are correct the Schwarzschild radius is not the limit of the gravitational lensing. It is just the inner edge. Still a 4 solar mass black hole will have the same gravitational lensing at a given radius as a 4 solar mass star or any other 4 solar mass object, assuming light can pass at that radius.

The point being, looking for lensing at 1000 light years in a path traced by something even several times the Schwarzschild radius of the black hole described will extremely impressive.

Even if the lensing radius were larger by a factor of 20, angular resolution required would still be less than a millionth OF a billionth of a degree.

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#38
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Re: A Black Hole System Visible to the Naked Eye

05/15/2020 7:02 AM

Consider that arrays of widely spaces radio telescopes creating huge artificial aperatures have a achieved around one milliarcsecond resolution. If that was improved a by a factor of a billion, it still would be unlikely to detail lensing from that black hole.

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#39
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Re: A Black Hole System Visible to the Naked Eye

05/15/2020 10:23 AM

Going back to my posts (9,14, 19 & 24) about re-classification of astrophysical objects, will the lack of "perceivable" lensing be the Pluto characteristic for diminutive sub-classing?

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#40
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Re: A Black Hole System Visible to the Naked Eye

05/15/2020 12:42 PM

Okay. i am absolutely wrong. It appears gravitational lensing from stellar mass black holes at even larger distances is more than just feasible...it has already occurred.

I retract my previous assertions.

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#41
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Re: A Black Hole System Visible to the Naked Eye

05/15/2020 12:56 PM

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