How Far Is the Closest Black Hole

Short answer

• The closest known black hole to Earth is Gaia BH1, about 1,560 light-years away in the constellation Ophiuchus, as measured in November 2022. It is a dormant stellar-mass black hole with about 10 times the mass of the Sun, orbiting a Sun-like star once every 185.6 days. That distance is the current record as of November 2026, and it is a record for the closest black hole astronomers have found, not a claim that no closer black hole exists. The famous supermassive black hole at the center of our galaxy, Sagittarius A*, is a different object entirely, about 26,000 light-years away, so it is roughly 17 times farther from us than Gaia BH1.

What a light-year measures

A light-year sounds like a unit of time, but it is a unit of distance. NASA defines it simply as the distance light travels in one year. Light moves through space at about 186,000 miles (300,000 kilometers) per second, and over a full year that adds up to about 5.88 trillion miles (9.46 trillion kilometers). One light-year is that distance.

That definition matters here, because it turns the answer into a travel time for light itself. The light we would see from the neighborhood of Gaia BH1 today left that system about 1,560 years ago, around the year 466 by our calendar. Anything slower than light, which means every spacecraft humans have ever built, would take far longer to cover the same gap.

Astronomers also use two other units for these distances, and readers will meet both in news reports. One parsec equals 3.26 light-years, so Gaia BH1 sits about 478 parsecs away. The astronomical unit, or AU, is the average distance from Earth to the Sun, about 93 million miles. Gaia BH1 is about 98 million AU away, a number so large that it is useless for everyday thinking, which is exactly why astronomers prefer light-years for distances between stars.

To feel the scale, compare Gaia BH1 with nearer landmarks. The Sun is about 8 light-minutes from Earth, meaning its light takes 8 minutes to reach us. The nearest star system beyond the Sun, Alpha Centauri, is about 4.3 light-years away, according to NASA. Gaia BH1 is about 360 times farther away than Alpha Centauri. The nearest large galaxy beyond our own, Andromeda, is about 2.5 million light-years away, which makes Gaia BH1, at 1,560 light-years, a genuinely local neighbor by galactic standards, even though it is far beyond any possible visit.

The answer: Gaia BH1, about 1,560 light-years away

Gaia BH1 is the closest black hole known to science as of November 2026. The figure comes from the team that discovered it, led by Kareem El-Badry of the Max Planck Institute for Astronomy and the Harvard-Smithsonian Center for Astrophysics, using data from the European Space Agency’s Gaia spacecraft. The Max Planck Institute for Astronomy reports the distance as around 1,560 light-years, and Guinness World Records lists the same figure, 1,560 light-years, with a mass of 9.62 times that of the Sun. Some popular summaries round the distance to 1,600 light-years or 1,500 light-years, but 1,560 light-years is the precise published figure, and it is the one used throughout this article.

The system sits in the constellation Ophiuchus, the serpent bearer, in the direction of the center of the Milky Way but far closer to us than the galactic center. It is a binary system, which means two objects orbit each other. One is a star very similar to our own Sun, a G-type main-sequence star with about 0.93 times the Sun’s mass. The other is the black hole, with a mass of about 10 times the Sun, or 9.27 solar masses in the most precise published measurement. The two orbit each other once every 185.6 days, at a separation of about the same distance as Earth orbits the Sun.

That orbital picture is worth pausing on, because it is the heart of the discovery. Imagine the solar system with a black hole where the Sun sits, and our Sun moved out to where Earth sits, circling the black hole once every six months. That is Gaia BH1, almost exactly. The companion star is ordinary, the orbit is wide and calm, and nothing dramatic is happening there right now.

Gaia BH1 is what astronomers call a dormant black hole. It is not pulling gas from its companion star, it has no glowing accretion disk, and it gives off no X-rays. In the words of the European Space Agency’s reporting on the related Gaia BH3 discovery, a dormant black hole “does not generate any light and is extremely difficult to spot.” That silence is the reason Gaia BH1 stayed hidden until 2022, even though it is the nearest black hole we know. A feeding black hole announces itself with X-rays and bright, hot gas. A dormant one betrays itself only through gravity, by tugging on a visible companion star.

If you are new to the subject, the background helps: a black hole is a region where mass has collapsed so densely that nothing, not even light, can escape its gravity. Our explainer on What Is a Black Hole sets out the types, from stellar-mass black holes like Gaia BH1 to supermassive ones like Sagittarius A*, and explains the event horizon, the point of no return around each one.

How astronomers found a black hole they cannot see

Nobody has seen Gaia BH1 directly, and nobody ever will with a telescope, because a black hole emits no light of its own. Astronomers found it the way detectives find an invisible suspect: by watching what it does to something visible.

The tool was the European Space Agency’s Gaia spacecraft, launched in December 2013 to measure the positions and motions of more than a billion stars with extraordinary precision. Gaia tracks each star’s tiny movements across the sky, a technique called astrometry. When a visible star wobbles in a regular pattern, that wobble can reveal an unseen companion pulling on it. The size and timing of the wobble reveal the companion’s mass.

When Gaia’s third data release appeared in June 2022, El-Badry and his colleagues searched its catalog of 168,065 binary star orbits for systems where a luminous star was being dragged around by a heavy invisible companion. They narrowed the list to six candidates, then used spectra, the rainbow-like breakdown of starlight that reveals motion toward or away from us, to test each one. Three candidates failed at once, because their spectra contradicted the Gaia orbit. One more failed because its orbit fit the data badly. One remains under study. The last candidate, cataloged as Gaia DR3 4373465352415301632 and nicknamed Gaia BH1, passed every check.

The team then confirmed it with targeted observations from four ground-based telescopes: the 6.5-meter Magellan Clay telescope, the 8.1-meter Gemini North telescope, the 10-meter Keck I telescope, and the 2.2-meter ESO/MPG telescope at La Silla Observatory in Chile. The W. M. Keck Observatory reports that the follow-up work showed the companion is a black hole about 10 times more massive than the Sun. El-Badry described the result as “the first unambiguous detection of a Sun-like star in a wide orbit around a stellar-mass black hole in our galaxy,” a careful phrase that reflects how many earlier claims of quiet black holes had later fallen apart.

The mass measurement is what rules out every alternative. If the invisible object were an ordinary star with 10 times the Sun’s mass, it would shine far brighter than its companion, and Gaia and the follow-up telescopes would have seen it. They saw nothing there. If it were a pair of smaller stars, their combined light would still show. A neutron star cannot be that heavy. Only a black hole fits the measurements, which is why the discovery paper and the Max Planck Institute describe Gaia BH1 as an excellent candidate that the data strongly support, rather than a directly photographed object.

One puzzle remains, and the discoverers are open about it. The star that became the black hole must have started life with at least 20 times the Sun’s mass, and such a star would have swollen into a supergiant before it collapsed, engulfing the space where its companion now orbits peacefully. How the Sun-like star survived that phase is not yet explained. The Max Planck Institute notes that one possibility is that the system formed inside a star cluster, where close encounters with other stars later shrank its orbit, and another is that the “black hole” is actually a pair of black holes orbiting each other closely. Precise future observations may settle that question, but either way the system contains at least one black hole, and its distance from Earth is unchanged.

The runners-up: the next closest black holes

Gaia BH1 did not just take the record, it smashed it. The W. M. Keck Observatory notes that it is three times closer than the previous record holder. The table below lists the nearest known black holes as of November 2026, with each distance carrying its own date stamp, because these figures change as new objects are found and old ones are remeasured.

Gaia BH3, discovered in 2024, is the second closest known black hole and the most remarkable of the runners-up. The European Space Agency reports that it sits 1,926 light-years away in the constellation Aquila, with a mass of nearly 33 times the Sun, making it the most massive stellar-mass black hole yet found in the Milky Way. Like Gaia BH1, it is dormant, betrayed only by the wobble of its companion, an ancient giant star that formed in the first two billion years after the Big Bang. Its companion orbits at about 16 times the Sun-Earth distance, a much wider orbit than Gaia BH1’s. The discovery was announced in April 2024 in the journal Astronomy and Astrophysics, and it came from pre-release Gaia data checked ahead of the mission’s fourth data release.

Gaia BH2, found in the same Gaia sweep as BH1 and announced in 2023, sits about 3,800 light-years away in Centaurus, with a mass of about 9 solar masses. It is also dormant, and it shows the pattern clearly: the Gaia mission is finding the quiet black holes that earlier X-ray searches could never see, because it looks for gravity, not light.

The older record holders were all found the old way, through X-rays from feeding black holes. V616 Monocerotis, also cataloged as A0620-00, sits about 4,700 light-years away in the constellation Monoceros. It orbits a star with about half the Sun’s mass, and it held the distance record before Gaia BH1 was found. Cygnus X-1, in the constellation Cygnus, is the classic textbook black hole, a bright X-ray source that has been studied since the 1970s, at a distance of about 7,200 light-years. XTE J1118+480, in Ursa Major, is another confirmed black hole closer than Cygnus X-1, at about 5,700 light-years. For decades, those X-ray binaries were the only nearby black holes astronomers knew, because they were the only ones that shone.

That history explains why the record changed so suddenly. Astronomers were not finding the nearest black holes first. They were finding the loudest ones first, and the loudest are not necessarily the closest. The quiet majority, the dormant black holes in wide orbits, were invisible to X-ray telescopes, and only Gaia’s precise star tracking could reveal them.

How a black hole like Gaia BH1 comes to exist at all is a story of a massive star’s death. Our guide to How Are Black Holes Formed walks through the collapse of a massive star’s core, the supernova that follows, and the mass thresholds that decide whether the remnant becomes a neutron star or a black hole.

The black hole that was not there: the HR 6819 lesson

Any article about the closest black hole should tell the story of HR 6819, because it explains why astronomers are so careful with the word “known.”

In May 2020, a team led by Thomas Rivinius of the European Southern Observatory announced that HR 6819, a bright star system in the constellation Telescopium, contained the closest black hole ever found, about 1,000 light-years away. The system appeared to hold two stars plus a black hole, with one star orbiting the invisible object every 40 days. News reports called it the closest black hole to Earth, and for nearly two years that claim stood in headlines and popular articles.

Other astronomers were skeptical from the start. Julia Bodensteiner, then a doctoral student at KU Leuven in Belgium, proposed a different explanation for the same data: the system might contain only two stars, with one star stripped of much of its atmosphere by its companion, a process sometimes called stellar vampirism. In that picture there was no black hole at all, only two stars in a 40-day orbit that mimicked the signature of one.

In March 2022, the two teams joined forces to settle the question with new observations from the European Southern Observatory’s Very Large Telescope and Very Large Telescope Interferometer in Chile. The MUSE instrument found no bright companion in a wide orbit, as the black hole picture required, and the GRAVITY instrument resolved two bright sources separated by only about one-third of the Earth-Sun distance. The European Southern Observatory’s press release of 2 March 2022 states the conclusion plainly: HR 6819 “is a binary system with no black hole,” caught in a rare and short-lived stage shortly after one star sucked the atmosphere off its companion.

The lesson is not that astronomers were careless. It is that a black hole claim based on spectra alone can be fooled, and that the Gaia method, which combines Gaia’s sky positions with spectra, is stronger precisely because it cross-checks two independent measurements. It is also why this article date-stamps every distance and labels candidates as candidates. The closest known black hole is a title that has changed hands before, and it will change hands again. The HR 6819 story is the reason careful writers say “closest known” rather than “closest.”

Sagittarius A*: the giant at the center, much farther away

The most common confusion about the closest black hole involves Sagittarius A*, the supermassive black hole at the center of the Milky Way. It is the most famous black hole in the sky, the one whose image made headlines around the world in May 2022, and many readers assume it must also be the nearest. It is not. It is a completely different object, of a completely different kind, at a completely different distance.

Sagittarius A*, usually written Sgr A*, sits about 26,000 light-years from Earth, in the direction of the constellation Sagittarius. That is roughly 17 times farther away than Gaia BH1. Some authorities round the figure to 27,000 light-years, because the best measurement of its distance is 8,277 parsecs, which converts to about 27,000 light-years, and different authors round differently. This article uses 26,000 light-years, the commonly quoted rounded figure, and the difference between 26,000 and 27,000 is a rounding choice, not a disagreement about where the object is.

The mass difference is even larger. Sagittarius A* has a mass of about 4 million times the Sun, or 4.297 million solar masses in the most precise current estimate. Gaia BH1, at about 10 solar masses, is roughly 400,000 times less massive. If Gaia BH1 is a cannonball, Sagittarius A* is a mountain range. The two objects belong to different classes: stellar-mass black holes form from single collapsed stars, while supermassive black holes, millions to billions of times the Sun’s mass, sit at the centers of galaxies and grow over billions of years.

The Event Horizon Telescope Collaboration released the first image of Sagittarius A* on 12 May 2022, the second black hole image ever made, after the 2019 image of the black hole in the galaxy M87. The image shows a glowing ring of hot gas bent around a dark central shadow, and it confirmed decades of work tracking stars orbiting the galactic center, work that earned Reinhard Genzel and Andrea Ghez a share of the 2020 Nobel Prize in Physics. None of that makes Sagittarius A* close. It makes it important, and it makes it the anchor around which our whole galaxy turns, including our solar system, which orbits the galactic center once every 225 million years or so.

Keep the two objects separate in your mind. Gaia BH1 is the nearest known black hole, small, quiet, and about 1,560 light-years away. Sagittarius A* is the nearest supermassive black hole, enormous, and about 26,000 light-years away. The word “nearest” needs its category attached, or it misleads.

Why the closest known black hole is probably not the closest black hole

Here is the most surprising part of the answer: astronomers are fairly confident that a black hole closer than Gaia BH1 exists. They just have not found it yet.

The Max Planck Institute for Astronomy estimates that there are about 100 million stellar-mass black holes in the Milky Way, while only a small fraction has been detected so far. The known ones number in the dozens when counted by telescope observations, plus the mergers detected by gravitational wave observatories. That leaves an enormous hidden population, and most of it is dormant, giving off no light at all.

The arithmetic is simple to sketch. If 100 million black holes are spread through the Milky Way, the average gap between neighbors is small on galactic scales, and the nearest one should statistically be much closer than 1,560 light-years. One astronomer quoted in coverage of the HR 6819 discovery estimated that if black holes were spread evenly, the closest should be just 30 to 40 light-years away. That is an idealized estimate, because black holes are not spread evenly, they cluster where stars formed, but it shows the direction of the reasoning: 1,560 light-years is a long way to the nearest member of a population of 100 million.

There are two reasons the nearer ones stay hidden. First, a dormant black hole in a wide orbit, or with no companion at all, is effectively invisible. It emits nothing, and unless a star happens to orbit it closely enough for Gaia to measure the wobble, there is nothing to measure. Second, a lone black hole wandering through space, one that was kicked out of its birth system by its supernova explosion, has no companion to betray it. The only way to spot such an object is gravitational microlensing, watching its gravity briefly bend and brighten the light of a more distant star as it passes in front of it. That technique works, but it requires patience and luck, because the alignment has to be exact and the brightening lasts only weeks or months. It has already worked once: OGLE-2011-BLG-0462, confirmed in 2022, is an isolated black hole about 5,200 light-years away, found by microlensing.

Gaia’s fourth data release, expected after the mission’s survey data are fully processed, should reveal dozens more dormant black holes in binary systems, according to the Gaia BH1 discovery team. Each new release narrows the gap between the closest known black hole and the closest actual black hole. The record of 1,560 light-years is therefore best read as a progress report, not a final answer. It tells us how far our search has reached, not how far the nearest black hole really is.

That distinction matters for how to read headlines. When a new “closest black hole” is announced, the honest question is not “is this the closest black hole in the galaxy,” because nobody can know that. The honest question is “is this the closest black hole we have confirmed so far, and how solid is the evidence.” Gaia BH1 passes that test better than any previous record holder, because two independent kinds of measurement, Gaia’s astrometry and ground-based spectra, agree on it.

To put Gaia BH1 in its galactic context, it helps to know how many stars and systems share our neighborhood. Our guide to How Many Galaxies Are There explains the scale of the Milky Way and the wider universe, and why a distance of 1,560 light-years, vast to us, counts as local in astronomy.

Is the closest black hole dangerous?

No. Gaia BH1 poses no danger to Earth, and neither does any other known black hole, for reasons that come straight from how gravity works.

Gravity weakens with distance, and 1,560 light-years is an immense distance. A black hole’s gravity at a given distance is exactly the same as the gravity of a star with the same mass at the same distance. Gaia BH1 has about 10 times the Sun’s mass, so at 1,560 light-years it pulls on us about as much as a 10-solar-mass star would at that distance, which is to say, not at all in any way we could measure. The Sun, at 8 light-minutes away, dominates our lives gravitationally. The Moon, at about 1.3 light-seconds, raises the tides. Gaia BH1, at 1,560 light-years, does nothing to us at all.

The danger zone of a black hole is its event horizon, and for a black hole of about 9.3 solar masses that horizon is only about 28 kilometers across, roughly the size of a city. You would have to travel almost all the way to Gaia BH1 before its gravity became a threat, and at that point the danger would be no different in kind from standing next to any extremely dense object. Black holes do not suck things in from across space. That popular image is wrong, and NASA’s own explainers make the point: a black hole is not a cosmic vacuum cleaner. If the Sun were replaced by a black hole of the same mass, Earth would keep orbiting exactly as it does now, in darkness, but in the same orbit.

Gaia BH1 is also dormant, which removes the other possible hazard. A feeding black hole can blast out X-rays and jets of particles from the hot gas spiraling into it, but Gaia BH1 has no accretion disk and is not feeding, so it emits no such radiation. Its companion star orbits it calmly, once every 185.6 days, and shows no sign of being pulled apart. The system is stable, and it will stay that way for far longer than human civilization has existed.

Sagittarius A* is equally harmless at its distance of about 26,000 light-years. It is mostly dormant too, only occasionally swallowing gas or dust, and its gravity at our distance is simply part of the general pull that keeps the galaxy together. The stars near the galactic center, whipping around it at high speed, are the ones that feel its power. We do not.

The honest caveat is that an undiscovered black hole much closer to Earth, perhaps a lone wanderer passing through the solar neighborhood, would be a different story in principle, but there is no evidence that any such object is near us, and astronomers would notice its gravitational effect on the outer solar system if it were close. The nearest known black hole is 1,560 light-years away, and there is no known threat at any distance that matters.

Could we ever visit it, and can we see it?

Light itself needs 1,560 years to travel from Gaia BH1 to Earth, so no spacecraft, which must travel slower than light, could make the trip in a human lifetime, or in many lifetimes. Even Voyager 1, the fastest spacecraft ever to leave the solar system, would need about 17,600 years to cover a single light-year, let alone 1,560 of them. Gaia BH1 is a destination for telescopes, not for travelers, and that will remain true for the foreseeable future.

You cannot see Gaia BH1 with the naked eye either. The black hole itself emits no light, and its companion star is far too faint to pick out without a telescope, even if you knew exactly where to look in Ophiuchus. Ophiuchus is a large constellation along the ecliptic, the path the Sun takes across the sky, and it is best placed for evening viewing in the summer months from northern latitudes, but finding the system means using star charts and a telescope, and even then you would be looking at a faint star, not at a black hole. The black hole reveals itself only in data: in Gaia’s precise measurements of that star’s wobble, and in spectra taken by large telescopes.

What you can see, on a dark night, is the Milky Way itself, the band of light that marks our galaxy seen from inside. Gaia BH1 sits inside that band, in the direction of the galactic center, among the crowded star fields of Ophiuchus. Knowing that a black hole hides among those stars, invisible and silent, is a different kind of seeing, and for most readers it is the more rewarding one.

Will the answer change?

Almost certainly, yes, and that is a sign of a healthy science rather than a weakness. The history of this record is a history of revisions: V616 Monocerotis at about 4,700 light-years, then the HR 6819 claim of 1,000 light-years that turned out to contain no black hole at all, then Gaia BH1 at 1,560 light-years, then Gaia BH3 at 1,926 light-years confirming that Gaia’s method keeps working. Each step came from better data, and each step corrected or replaced what came before.

Gaia’s fourth data release is the next milestone to watch. The discovery team expects it to reveal dozens of similar dormant black holes, and any one of them could be closer than Gaia BH1. Gravitational microlensing surveys may also find lone black holes with no companion star, including ones closer than any binary system. When that happens, the number in this article will need updating, and the date stamp on the distance, November 2026, will tell the reader exactly when the figure was current.

That is also why this article keeps the wording careful throughout. “Closest known” is a statement about the state of astronomy in November 2026. “Closest” without qualification would be a claim about the universe, and nobody can make that claim honestly. The universe keeps its secrets, and astronomers keep finding them, one wobbling star at a time.

Frequently asked questions

How far is the closest black hole from Earth?

As of November 2026, the closest known black hole is Gaia BH1, about 1,560 light-years away in the constellation Ophiuchus. It was discovered in 2022 using data from the European Space Agency’s Gaia spacecraft. Closer black holes almost certainly exist but have not been found yet, because dormant black holes emit no light.

What is the closest black hole to Earth called?

It is called Gaia BH1, from the Gaia spacecraft that revealed it, with the catalog designation Gaia DR3 4373465352415301632. It is a dormant stellar-mass black hole of about 10 solar masses, orbiting a Sun-like star every 185.6 days.

How far is Sagittarius A* from Earth?

Sagittarius A*, the supermassive black hole at the center of the Milky Way, is about 26,000 light-years from Earth, roughly 17 times farther away than Gaia BH1. It has a mass of about 4 million times the Sun. It is the nearest supermassive black hole, but it is not the nearest black hole overall.

Is the closest black hole dangerous to Earth?

No. Gaia BH1 is about 1,560 light-years away, it is dormant and not feeding, and at that distance its gravity has no measurable effect on Earth. A black hole’s gravity at a given distance is the same as a star of the same mass at the same distance, and its dangerous region, the event horizon, is only about 28 kilometers across.

Can you see the closest black hole?

No, not directly. A black hole emits no light, and Gaia BH1’s companion star is too faint to see with the naked eye. Astronomers found it by measuring the star’s wobble with the Gaia spacecraft and confirming the orbit with large ground-based telescopes. Its location is in the constellation Ophiuchus.

Will a closer black hole be found?

Very likely. Astronomers estimate there are about 100 million stellar-mass black holes in the Milky Way, and only a small fraction have been found. Gaia’s next data release is expected to reveal dozens more dormant black holes, and any of them could be closer than Gaia BH1’s 1,560 light-years.

Why was HR 6819 not the closest black hole?

In 2020, HR 6819 was announced as the closest black hole, about 1,000 light-years away. Follow-up observations in 2022 by the European Southern Observatory showed the system contains only two stars and no black hole, after one star stripped the atmosphere from its companion. The claim was withdrawn, and Gaia BH1 took the record.

Sources & references

• * NASA Science, "What is a light-year?": light travels about 186,000 miles (300,000 kilometers) per second and 5.88 trillion miles (9.46 trillion kilometers) per year; a light-year is the distance light travels in one year. Accessed 5 November 2026.
• * NASA Science, "Cosmic Distances": one AU is about 93 million miles; Alpha Centauri is about 4.3 light-years away; the Sun is about 8 light-minutes from Earth; one parsec is 3.26 light-years. Accessed 5 November 2026.
• * Max Planck Institute for Astronomy, "New method finds black hole closest to Earth" (November 2022): Gaia BH1 at around 1,560 light-years, about 10 solar masses, orbiting a Sun-like star every 185.6 days; an estimated 100 million stellar black holes in the Milky Way; Gaia DR3 contained 168,065 binary orbits. Accessed 5 November 2026.
• * W. M. Keck Observatory, "New Record: Nearest Known Black Hole to Earth Discovered" (November 2022): Gaia BH1 at 1,560 light-years in Ophiuchus, three times closer than the previous record holder; first unambiguous detection of a Sun-like star in a wide orbit around a stellar-mass black hole. Accessed 5 November 2026.
• * European Space Agency via the Institute of Astronomy, University of Cambridge, "Sleeping giant surprises Gaia scientists" (16 April 2024): Gaia BH3 at 1,926 light-years in Aquila, about 33 solar masses, the most massive stellar-mass black hole yet found in the Milky Way; dormant black holes generate no light and are extremely difficult to spot. Accessed 5 November 2026.
• * European Southern Observatory, "Closest black hole system found to contain no black hole" (ESO press release eso2204, 2 March 2022): HR 6819 is a binary system with no black hole; the 2020 claim of a black hole 1,000 light-years away was refuted by Very Large Telescope observations. Accessed 5 November 2026.
• Event Horizon Telescope Collaboration, first image of Sagittarius A (12 May 2022), as reported by the European Southern Observatory and the collaboration: Sagittarius A* at about 26,000 to 27,000 light-years, with a mass of about 4 million times the Sun; the second black hole image ever made, after M87* in 2019. Accessed 5 November 2026.
• * Miller-Jones et al., Science (2021), "Cygnus X-1 contains a 21-solar mass black hole": radio astrometry refines the distance to Cygnus X-1 to 2.22 kiloparsecs, about 7,200 light-years, with a black hole mass of 21.2 solar masses. Accessed 5 November 2026.
• * Sahu et al., The Astrophysical Journal (2022), "An Isolated Stellar-mass Black Hole Detected through Astrometric Microlensing": OGLE-2011-BLG-0462, the first confirmed isolated black hole, at a distance of 1.58 kiloparsecs, about 5,200 light-years, with a mass of 7.1 solar masses. Accessed 5 November 2026.
• * Nagarajan et al., Publications of the Astronomical Society of the Pacific (2024), "ESPRESSO Observations of Gaia BH1": refined Gaia BH1 black hole mass of 9.27 solar masses from high-precision radial velocity observations. Accessed 5 November 2026.
• * Gelino et al., The Astrophysical Journal (2006), "The inclination angle and mass of the black hole in XTE J1118+480": distance 1.72 ± 0.10 kiloparsecs, about 5,700 light-years, black hole mass 8.53 ± 0.60 solar masses. Accessed 5 November 2026.