Black Hole Discovered Lurking in Star Cluster Outside Our Galaxy

This artist’s impression shows a compact black hole 11 times as massive as the Sun and the five-solar-mass star orbiting it. The two objects are located in NGC 1850, a cluster of thousands of stars roughly 160,000 light-years away in the Large Magellanic Cloud, a Milky Way neighbor. The distortion of the star’s shape is due to the strong gravitational force exerted by the black hole.
Not only does the black hole’s gravitational force distort the shape of the star, but it also influences its orbit. By looking at these subtle orbital effects, a team of astronomers was able to infer the presence of the black hole, making it the first small black hole outside of our galaxy to be found this way. For this discovery, the team used the Multi Unit Spectroscopic Explorer (MUSE) instrument at ESO’s Very Large Telescope in Chile. Credit: ESO/M. Kornmesser

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have discovered a small black hole outside the Milky Way by looking at how it influences the motion of a star in its close vicinity. This is the first time this detection method has been used to reveal the presence of a black hole outside of our galaxy. The method could be key to unveiling hidden black holes in the Milky Way and nearby galaxies, and to help shed light on how these mysterious objects form and evolve.

The newly found black hole was spotted lurking in NGC 1850, a cluster of thousands of stars roughly 160,000 light-years away in the Large Magellanic Cloud, a neighbor galaxy of the Milky Way.

“Similar to Sherlock Holmes tracking down a criminal gang from their missteps, we are looking at every single star in this cluster with a magnifying glass in one hand trying to find some evidence for the presence of black holes but without seeing them directly,” says Sara Saracino from the Astrophysics Research Institute of Liverpool John Moores University in the UK, who led the research now accepted for publication in Monthly Notices of the Royal Astronomical Society. “The result shown here represents just one of the wanted criminals, but when you have found one, you are well on your way to discovering many others, in different clusters.”

This image shows NGC1850, a cluster of thousands of stars roughly 160,000 light-years away in the Large Magellanic Cloud, a Milky Way neighbor. The reddish filaments surrounding the cluster, made of vast clouds of hydrogen, are believed to be the remnants of supernova explosions.
The image is an overlay of observations conducted in visible light with ESO’s Very Large Telescope (VLT) and NASA/ESA’s Hubble Space Telescope (HST). The VLT captured the wide field of the image and the filaments, while the central cluster was imaged by the HST.
Among many stars, this cluster is home to a black hole 11 times as massive as the Sun and to a five-solar-mass star orbiting it. By looking at the star’s orbit, a team of astronomers was able to infer the presence of the black hole, making it the first small black hole outside of our galaxy to be found this way. For this discovery, the team used the Multi Unit Spectroscopic Explorer (MUSE) instrument at the VLT. Credit: ESO, NASA/ESA/M. Romaniello

This first “criminal” tracked down by the team turned out to be roughly 11 times as massive as our Sun. The smoking gun that put the astronomers on the trail of this black hole was its gravitational influence on the five-solar-mass star orbiting it.

Astronomers have previously spotted such small, “stellar-mass” black holes in other galaxies by picking up the X-ray glow emitted as they swallow matter, or from the gravitational waves generated as black holes collide with one another or with neutron stars.

However, most stellar-mass black holes don’t give away their presence through X-rays or gravitational waves. “The vast majority can only be unveiled dynamically,” says Stefan Dreizler, a team member based at the University of Göttingen in Germany. “When they form a system with a star, they will affect its motion in a subtle but detectable way, so we can find them with sophisticated instruments.”

This dynamical method used by Saracino and her team could allow astronomers to find many more black holes and help unlock their mysteries. “Every single detection we make will be important for our future understanding of stellar clusters and the black holes in them,” says study co-author Mark Gieles from the University of Barcelona, Spain.

The detection in NGC 1850 marks the first time a black hole has been found in a young cluster of stars (the cluster is only around 100 million years old, a blink of an eye on astronomical scales). Using their dynamical method in similar star clusters could unveil even more young black holes and shed new light on how they evolve. By comparing them with larger, more mature black holes in older clusters, astronomers would be able to understand how these objects grow by feeding on stars or merging with other black holes. Furthermore, charting the demographics of black holes in star clusters improves our understanding of the origin of gravitational wave sources.

To carry out their search, the team used data collected over two years with the Multi Unit Spectroscopic Explorer (MUSE) mounted at ESO’s VLT, located in the Chilean Atacama Desert. “MUSE allowed us to observe very crowded areas, like the innermost regions of stellar clusters, analyzing the light of every single star in the vicinity. The net result is information about thousands of stars in one shot, at least 10 times more than with any other instrument,” says co-author Sebastian Kamann, a long-time MUSE expert based at Liverpool’s Astrophysics Research Institute. This allowed the team to spot the odd star out whose peculiar motion signaled the presence of the black hole. Data from the University of Warsaw’s Optical Gravitational Lensing Experiment and from the NASA/ESA Hubble Space Telescope enabled them to measure the mass of the black hole and confirm their findings.

ESO’s VISTA telescope reveals a remarkable image of the Large Magellanic Cloud, one of our nearest galactic neighbors. VISTA has been surveying this galaxy and its sibling the Small Magellanic Cloud, as well as their surroundings, in unprecedented detail. This survey allows astronomers to observe a large number of stars, opening up new opportunities to study stellar evolution, galactic dynamics, and variable stars. Credit: ESO/VMC Survey

ESO’s Extremely Large Telescope in Chile, set to start operating later this decade, will allow astronomers to find even more hidden black holes. “The ELT will definitely revolutionize this field,” says Saracino. “It will allow us to observe stars considerably fainter in the same field of view, as well as to look for black holes in globular clusters located at much greater distances.”

This chart maps the southern constellation Dorado and showcases other stars in that region of the sky, most of which can be seen with the naked eye on a clear dark night. NGC 1850 — a cluster of thousands of stars roughly 160,000 light-years away in the Large Magellanic Cloud, a Milky Way neighbor — is marked with a red circle. Credit: ESO, IAU and Sky & Telescope

Reference: “A black hole detected in the young massive LMC cluster NGC 1850” by S. Saracino, S. Kamann, M. G. Guarcello, C. Usher, N. Bastian, I. Cabrera-Ziri,
M. Gieles, S. Dreizler, G. S. Da Costa, T.-O. Husser and V. Hénault-Brunet, 11 November 2021, Monthly Notices of the Royal Astronomical Society.
DOI: 10.1093/mnras/stab3159

More information

This research was presented in a paper to appear in Monthly Notices of the Royal Astronomical Society.

The team is composed of S. Saracino (Astrophysics Research Institute, Liverpool John Moores University, UK [LJMU]), S. Kamann (LJMU), M. G. Guarcello (Osservatorio Astronomico di Palermo, Palermo, Italy), C. Usher (Department of Astronomy, Oskar Klein Centre, Stockholm University, Stockholm, Sweden), N. Bastian (Donostia International Physics Center, Donostia-San Sebastián, Spain, Basque Foundation for Science, Bilbao, Spain & LJMU), I. Cabrera-Ziri (Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany), M. Gieles (ICREA, Barcelona, Spain and Institut de Ciències del Cosmos, Universitat de Barcelona, Barcelona, Spain), S. Dreizler (Institute for Astrophysics, University of Göttingen, Göttingen, Germany [GAUG]), G. S. Da Costa (Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia), T.-O. Husser (GAUG) and V. Hénault-Brunet (Department of Astronomy and Physics, Saint Mary’s University, Halifax, Canada).

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration in astronomy. Established as an intergovernmental organization in 1962, today ESO is supported by 16 Member States (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland, and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor center and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvelous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal, and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates APEX and ALMA on Chajnantor, two facilities that observe the skies in the millimeter and submillimeter range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.

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  • Sf. Ramon Careaga, founder EPEMC

    Bullsnot. Electrokinetic forces. Black holes (classic) were falsified several years ago. All remaining onrs have become charged and are actually plasmoids with high electromagnetic fields. Get with the times. “Electric currents in geospace and Beyond”, AGU100, 2017

  • mullach abu

    nasa space images for training algorithims are all fake except one can you tell which is real just one out of 226 images is real can you spot which one it is
    artificial intelligence ai a stunning mosaic of fake space images used to train its astronomical algorithims but it has hidden within it a single image of a genuine cosmic marvel to calibrate them it is useful to test them on fake images of fake universes why would you want to fake a universe
    for one reason and one reason alone to better understand our real universe
    did the a1 have you fooled
    160,000 light years away from our sun the magellanic cloud
    and shelock holmes took out his magnifying glasses and looked at
    100 million years old main cluster young stars 50 million years old +- 10 million years irregular and showing a tail to the northwest a tidal radius of 10 light years overall radius 16 light years ngc1850
    and sherlock said to watson what do you reckon a rogue or an ally informant
    and watson he knew immediately by the powers of his deduction
    its elementary my dear holmes
    you see that there fake red blood spilled on the image by that there photographer
    yes watson that long thin red red streak thats still dripping down
    yes sherlock that there is an large magellanic cloud lms interstellar cold gas and dust cloud that is stretching your fake dimension of 1000 light years long and according to the dynamic flow of stellar objects that there ngc 1850 cluster has just passed through it 60,000 years ago and do you see the gap between the red cloud and the cluster well thats the distance its has travelled in 60,000 years in proper motion and whilst it was travelling in labour pains the blue stars starting being born
    so watson said to sherlock that leaves the fake red blood trail covered
    over to you if you can spot anything
    yup watson i was wondering if your powers of observation would have uncovered the intruder in the middle of the bunch
    the 11 times the mass of our sun the black hole influencing the dynamical motion of a nearby star which is about five times the mass of our sun
    and if it is only influencing one star in the bunch and you have the speed and velocity of all the stars in the bunch 100,000
    watson what radius diameter has the intruder got from the other bright stars that they are not being pulled into that intruder and black exit escape manhole there
    and will they have caught him before he disappears down that manhole to pull him away
    so that we can save ourselves a trip to the scene of the crime
    or will we have to wait to see the intruder resurface somewhere out there in the middle of that blackhole manhole and where and when should we leave and go to discover the intruder there

    • Torbjörn Larsson

      But of course your claim of “fake” against evidence is fake since you have no science backing you up.

      Why are you even trying push conspiracy idea!? No one is fooled.

      • mullach abu

        did you take the test yet
        NASA space images for training algorithms are all fakehttps://vigourtimes.com › nasa-space-images-for-trainin…
        9 Nov 2021 — Can YOU tell which is real? NASA reveals the fake space images used to train its astronomical algorithms – with just one of these 225 snaps …

  • Candi

    I seldom read comments for reasons I’m not in the mood to disclose but I will say that Mullachs comment is a great example of why I refuse to waste my time. Why am I choosing to share my thoughts now then. Well I thought to myself maybe just maybe since this is a science/tech site I wouldn’t have to endure the standard delusional conspiratorial psychobabble shared by the devolved internet parasites frequenting every single comment section known to man. Im down for ECT just so I can rid my brain of the necrotizing garbage destroying the world.

  • R Rytter

    Great observation: a young star orbiting a black hole, outside our milky way galaxy. Simple and straightforward reading 👍 thank you! Yes, what an observation!

    • Torbjörn Larsson

      The good news is that the new method promise to complement the LIGO/Virgo work on black hole statistics – the O3 run seems to have closed the 2-5 solar mass “mass gap” since they found the expected amount of black holes in there [ https://bigthink.com/starts-with-a-bang/mass-gap-dead/ ].

  • R Rytter

    I’m tempted to come up with this comment: If we say, a galaxy must start somewhere, then what we see here, could be a galaxy-embryo. ..

  • Olaf Olafson

    You guys really need to work on your grammer and writing. I saw Kindergarten kids with better englisch skills than you guys.
    Do you even rrad your articles after composing it?