Artist's impression of a black hole that is 11 times larger than the Sun and five times more massive than the star with five solar-mass orbiting it. These two objects are found in NGC1850, a cluster of thousands stars located approximately 160 000 light years away in the Large Magellanic Cloud. This is a Milky Way neighbor. The strong gravitational force exerted on the black hole causes the star to distort its shape. The black hole's strong gravitational force not only distorts the star's shape but also affects its orbit. A team of astronomers was able to identify the existence of the black hole by looking at the subtle orbital effects. This makes it the first small black hole to be discovered outside of our galaxy. The Multi Unit Spectroscopic Explorer instrument (MUSE) at ESO's Very Large Telescope, Chile was used by the team to make this discovery. Credit: ESO/M. Kornmesser
Astronomers discovered a small black spot outside of the Milky Way using the European Southern Observatory's Very Large Telescope. This telescope is used to observe how the black hole affects the motion of stars in its vicinity. This detection method is new and it has revealed a black hole beyond our galaxy for the first time. This method may be the key to uncovering hidden black holes within the Milky Way or nearby galaxies. It could also help shed light on how these mysterious objects evolve.
The black hole, which was discovered in NGC 1850, is a cluster of thousands stars located approximately 160 000 light-years from the Large Magellanic Cloud. It is a neighbor galaxy to the Milky Way.
"This is similar to Sherlock Holmes pursuing a criminal gang, we are looking at each star in this cluster using a magnifying lens in one hand trying find evidence for the existence of black holes, but without actually seeing them," Sara Saracino, from the Astrophysics Research Institute of Liverpool John Moores University in the UK who led the research that was accepted for publication in Monthly Notices of the Royal Astronomical Society. The result here is only one of the wanted criminals. However, once you have located one, you can start to find others in other clusters.
The team found that the first "criminal", which was discovered by them, was approximately 11 times larger than our Sun. Astronomers discovered the black hole's gravitational effect on the five-solar mass star that orbits it. This was the key to their discovery.
Astronomers have previously detected such small black holes with "stellar mass" in other galaxies. This was done by observing the X-ray glow they emit as they swallow matter or the gravitational waves that are generated when black holes collide with each other or with neutron star.
Most stellar-mass black hole don't reveal their existence through X-rays and gravitational waves. Stefan Dreizler, who is a member of the team and is based at the University of Gottingen, Germany says that "the vast majority cannot be unveiled dynamically." "When they form a system together with a star, they will influence its motion in subtle but detectable ways. This allows us to find them using sophisticated instruments."
Saracino and her colleagues used a dynamical method to locate black holes. This could help astronomers unlock their mysteries. Mark Gieles, a study co-author from the University of Barcelona in Spain, said that every single discovery will help us understand the future of star clusters and black holes.
NGC 1850 is the first time that a black hole was detected in a young star cluster. The cluster is just 100 million years old. This is a blink of an astronomical eye. Their dynamical method could be used in star clusters similar to NGC 1850 to reveal more young black holes, and shed light on their evolution. Astronomers could compare them to older, larger black holes in other clusters to better understand how they grow. Charting the demographics and ages of black holes within star clusters can help us understand the origin of gravitational waves.
The team used data from the Multi Unit Spectroscopic Explorer, (MUSE), collected over two years at ESO's VLT in the Chilean Atacama Desert to carry out their search. MUSE allowed us to see very crowded areas like the innermost regions in stellar clusters and analyze the light from every star in the area. Sebastian Kamann, co-author and a long-time MUSE specialist based at Liverpool’s Astrophysics Research Institute, says that the net result includes information about thousands of stars, at most 10 times greater than any other instrument. The team was able to identify the strange star whose unusual motion indicated the existence of the black hole. The University of Warsaw's Optical Gravitational Lensing Experiment, and the NASA/ESA Hubble Space Telescope allowed them to determine the mass of the black holes and confirmed their findings.
The ESO's Extremely Large Telescope (Chile) will be operational in the latter part of this decade. It will enable astronomers to discover more black holes. Saracino says that the ELT will revolutionize this field. It will enable us to see stars at much higher distances and also to search for black holes in globular clusters.
More information: S Saracino et al., A black hole was detected in the young massive LMC-cluster NGC 1850. Monthly Notices of the Royal Astronomical Society (2021). Information for the Journal: Monthly Notices from the Royal Astronomical Society, S Saracino et al., A black hole discovered in the young massive LMC-cluster NGC 1850 (2021). DOI: 10.1093/mnras/stab3159
Picha ya mchoraji ya shimo jeusi kubwa mara 11 kuliko jua na kubwa mara tano kuliko nyota inayozunguka. Mwili huu unaonekana katika NGC 1850, kundi la nyota elfu moja lililo karibu miaka ya mwanga 160 mbali katika wingu kubwa la Magellan. Hii ni jirani ya Mfereji wa Maziwa. Nguvu kubwa ya uvutano inayotumiwa juu ya shimo jeusi husababisha nyota hiyo kugeuza umbo lake. Nguvu kubwa ya uvutano ya shimo jeusi haibadili tu umbo la nyota bali pia huathiri mzunguko wake. Timu ya wataalamu wa nyota waliweza kutambua kuwepo kwa shimo jeusi kwa kuangalia athari ndogo za mzunguko. Hii inafanya iwe shimo jeusi dogo la kwanza kugunduliwa nje ya galaksi yetu. Kifaa cha Multi Unit Spectroscopic Explorer (MUSE) kilichowekwa kwenye darubini kubwa ya ESO huko Chile kilitumiwa na timu hiyo kufanya ugunduzi huu. Uhakikisho: ESO Wataalamu wa nyota wa Kornmesser wamegundua doa dogo jeusi nje ya Mfereji wa Maziwa wakitumia darubini ya European Southern Observatory (ESO) inayoitwa Very Large Telescope. Darubini hiyo hutumiwa kuchunguza jinsi shimo jeusi linavyoathiri mwendo wa nyota zilizo karibu nalo. Njia hii ya kugundua ni mpya na imefunua shimo jeusi zaidi ya galaksi yetu kwa mara ya kwanza. Njia hiyo yaweza kuwa ufunguo wa kufunua mashimo meusi yaliyofichwa ndani ya Mfereji wa Maziwa au galaksi zilizo karibu. Pia inaweza kusaidia kueleza jinsi vitu hivyo visivyoeleweka vinavyobadilika. Chungu hicho cha nyeusi, ambacho kiligunduliwa mwaka 1850, ni kundi la nyota elfu kadhaa zilizoko umbali wa miaka ya mwanga 160,000 kutoka kwa wingu kubwa la Magellan. Ni galaksi jirani ya Mfereji wa Maziwa. """Hii ni kama Sherlock Holmes akifuatilia kundi la wahalifu, tunatazama kila nyota katika kundi hili kwa kutumia lensi ya kuongeza katika mkono mmoja kujaribu kupata ushahidi wa kuwepo kwa mashimo meusi, lakini bila kuwaona,"" Sara Saraceno, kutoka Taasisi ya Utafiti wa Astrophysics ya Chuo Kikuu cha Liverpool John Moores, Uingereza, aliongoza utafiti ambao ulikubaliwa kuchapishwa katika Taarifa za Kila Mwezi za Royal Astronomical Society." Matokeo hapa ni mmoja tu wa wahalifu wanaotafutwa. Hata hivyo, mara tu unapopata moja, unaweza kuanza kupata nyingine katika makundi mengine. "Timu hiyo iligundua kwamba ""mhalifu"" wa kwanza, ambaye aligunduliwa na wao, alikuwa karibu mara 11 kubwa kuliko jua letu." Wataalamu wa nyota wamegundua athari ya mvuto wa shimo jeusi kwenye nyota yenye uzito wa jua tano inayolizunguka. Hilo ndilo lililokuwa ufunguo wa ugunduzi wao. Wataalamu wa nyota wamegundua hapo awali mashimo meusi madogo kama hayo yenye "uzito wa nyota" katika galaksi nyingine. Kwa mfano, uchunguzi wa X-ray unaonyesha kwamba nyota hizo hutekeleza mwangaza wa mawimbi ya uvutano wakati zinapogongana na nyota nyingine. Mashimo meusi mengi yenye uzito wa nyota hayafunui kuwepo kwake kupitia miale ya X na mawimbi ya uvutano. "Stefan Dreisler, mwanachama wa timu hiyo na anayehudumu katika Chuo Kikuu cha Göttingen, Ujerumani, anasema kwamba ""wengi wa habari hizo haziwezi kufunuliwa kwa njia ya moja kwa moja.""" "Wakati wao hufanyiza mfumo pamoja na nyota, wataathiri mwendo wake kwa njia zisizoeleweka lakini zinazoweza kugunduliwa. Hilo hutusaidia kuzipata kwa kutumia vyombo vya hali ya juu". Saracino na wenzake walitumia mbinu ya nguvu ili kupata mashimo meusi. Hilo laweza kuwasaidia wataalamu wa nyota kufunua mafumbo yao. "Mark Gieles, mwandishi mwenza wa utafiti huo kutoka Chuo Kikuu cha Barcelona nchini Hispania, alisema: ""Kila ugunduzi utatuwezesha kuelewa wakati ujao wa makundi ya nyota na mashimo meusi." NGC 1850 ni mara ya kwanza kwa kundi la nyota vijana kugundua shimo jeusi. Mkusanyiko huo una umri wa miaka milioni 100 tu. Hii ni kung'aa kwa jicho la astronomia. Kwa mfano, katika kundi la nyota la NGC 1850, kuna uwezekano wa kugundua mashimo meusi ya vijana na kuelezea jinsi yalivyobadilika. Wataalamu wa nyota wangeweza kulinganisha nyota hizo na mashimo meusi makubwa zaidi yaliyo katika makundi mengine ya nyota ili kuelewa vizuri jinsi yanavyokua. Kuchora ramani ya idadi ya watu na umri wa mashimo meusi ndani ya makundi ya nyota kunaweza kutusaidia kuelewa chanzo cha mawimbi ya uvutano. Utafiti huo ulijumuisha data kutoka kwa Multi Unit Spectroscopic Explorer (MUSE) iliyokusanywa kwa miaka miwili katika VLT ya ESO katika Jangwa la Atacama nchini Chile. MUSE ilituwezesha kuona maeneo yenye watu wengi sana kama vile maeneo ya ndani zaidi katika makundi ya nyota na kuchambua mwanga kutoka kwa kila nyota katika eneo hilo. Sebastian Kamann, mwandishi mwenza na mtaalamu wa muda mrefu wa MUSE, ambaye anaishi katika Taasisi ya Utafiti wa Astrophysics ya Liverpool, anasema matokeo ya jumla yanajumuisha habari kuhusu maelfu ya nyota, zaidi ya mara kumi zaidi kuliko chombo kingine chochote. Timu hiyo iliweza kutambua nyota hiyo isiyo ya kawaida ambayo mwendo wake usio wa kawaida ulionyesha kuwepo kwa shimo jeusi. Majaribio ya Optical Gravitational Lensing ya Chuo Kikuu cha Warsaw na darubini ya anga ya Hubble ya NASA na ESA yaliwawezesha kuamua wingi wa mashimo meusi na kuthibitisha matokeo yao. Teleskopi ya ESO ya Extremely Large Telescope (ESLT) itaanza kazi katika sehemu ya mwisho ya miaka kumi hii. Itasaidia wataalamu wa nyota kugundua mashimo mengi meusi. Saraceno anasema kwamba ELT itabadilisha uwanja huu. "Kutakuwa na uwezo wa kuona nyota zilizo mbali zaidi na pia kutafuta mashimo meusi katika makundi ya nyota ya dunia.""" "Saraceno na wenzake walipata ""shimo jeusi"" katika kundi la nyota la NGC 1850" Taarifa ya kila mwezi ya Royal Astronomical Society (2021). "Mwanzoni mwa mwaka wa 2015, jarida la ""Monthly Notices from the Royal Astronomical Society"" lilitoa taarifa kuhusu shimo jeusi lililogunduliwa katika kundi la nyota la NGC 2050." (Kwanza: 10109 M.N.R.S.S.S.S.S.S.S.S.S.S.)