It may not be the closestblack holeto Earth , but it ’s certainly the close one that astronomers have labeled as " supermassive . " Known as Sagittarius A * ( say “ Sagittarius A - star ” ) , the mysterious object , first detected in the seventies , count as much as 4 million Sun . shape by the prostration of large star , most black hole are n’t nearly that sizing .
Sagittarius A * sit at the very fondness of the Milky Way galaxy , some 25,000 light - age from our solar system — but until now , we have n’t known much about it . before long , however , thanks to a globe - cross array of wireless scope known as theEvent Horizon Telescope , astronomer will have their closest ever look at this oracular target .
The Event Horizon Telescope , or EHT , is appoint for the notorious “ point of no return ” that marks the outer bounds of a ignominious hole . ( The gravity of a black hole is so potent that nothing can escape it , not even light — thus the name . ) It incorporate huge , dish - shape telescope at six dissimilar land site on four Continent , include Antarctica and Hawaii . The array recently finish its most challenging observation so far , accumulate data of Sagittarius A * over a10 - solar day periodin mid - April .
“ We ’ve never had data of the quality that we ’ve just rent , ” Dan Marrone , an experimental astrophysicist at the University of Arizona , tells Mental Floss . When the data point is finally march — sometime this fall at the other — astronomer will have their clear scene yet of a black hole .
A VIEW OF THE EDGE
What that image will actually bet like , however , is still very much up in the air . We know that black holes are typically surrounded byaccretion record — band of dust and gas that whirlpool around the bleak hole , get ever - hotter as the material approaches the black hole’sevent horizon . The in - falling thing gets so hot that it emits radio waves and other radiation sickness ( which is how objects like Sagittarius A * were first detected ) . accumulation disks can also producejets — streams of high - energy speck that get blasted out from the black hole at near the speed of light . And we eff that the organization ’s acute gravity aeroembolism starlight as it passes near the grim kettle of fish . “ We might see a crescent , brightened on one side — or a bipolar , jet - like structure , ” Marrone says . “ We honestly do n’t bang . ”
stock optical telescope — even those mellow above the Earth ’s atmosphere , likeHubble — can tell us very little about objects like Sagittarius A * because there ’s too much gas and dust between us and the astronomic center for optical wavelengths to permeate ; it ’s like trying to peer across San Francisco Bay on the foggiest daytime of the year .
But radio telescope , taking vantage of the recollective wavelength of wireless waves , can see through the murk . The best wager , stargazer have detect , is to use scope sensitive to wavelengths of about 1 centimeter — longer than wavelength of infrared lighting , but unretentive than the waves that your car radio picks up .
Multiple radio telescopes , in different localization , can be made to do work together even better , simulating a much tumid instrument . This technique is experience as VLBI , for Very Long Baseline Interferometry . TheAtacama Large Millimeter - submillimeter Array , constitute 66 radio knockout in northern Chile , was recently supply to the EHT array , greatly boost the overall sensitivity ; the South Pole Telescope was also added to the array in April . The project now involve 30 institutions in 12 countries .
“ The Event Horizon Telescope is conk to be zooming in , to right wing where the inner bound of the accretion disk is falling in to the black jam — right on at the bound between where the disk textile end and the black hole take off , ” radio uranologist Joseph Lazio of NASA ’s Jet Propulsion Laboratory tell Mental Floss .
A BLACK HOLE WITHOUT MUCH OF AN APPETITE
Of of course , we can never see past theevent horizon — whatever ’s on the other side remains eternally beyond our reach . But with the conclude power of the EHT , stargazer will have their confining look yet at the region straight off outside it .
The EHT ’s purpose big businessman will be so of the essence because , despite Sagittarius A * ’s heft , it ’s not very large in terms of size . Its case purview is believed to cross just about 15 million miles — less than 20 times the diameter of the Sun .
And in venom of the public sensing of black maw as “ cosmic vacancy cleaners ” that suck up everything in sight , Sagittarius A * is really not much of an feeder . “ It ’s on a starvation diet , ” Marrone jokes . “ We do n’t know of another black hole that ’s eating so slowly , relative to its weight . ”
Another target for the EHT will be the black hole in the plaza of a galax known as M87 . This ginormous contraband hole is 1000 times farther away than Sagittarius A * , but it ’s also 1000 times more monumental ; it ’s so gravid that its gravity ground an entire bunch of galax , bed as the Virgo Cluster . And it hasenormous jets shooting outof its accretion saucer — something that astronomers are nervous to get a confining look at .
Beyond plainly see these jumbo black holes , the EHT may shake off some visible light on the complex family relationship between supermassive opprobrious holes and the galax that harbor them . Surveys using XTC - re telescope suggest that these heavy sinister holes are common ; they ’re believed to lurk in the hearts of most galaxies . But did the galaxies develop first , and then the black holes — or was it the other way around ?
WHAT CAME FIRST, THE BLACK HOLE OR THE GALAXY?
“ There ’s a very strong correlation coefficient between the property of these supermassive blackened hole and the properties of their host galaxy , ” David Spergel , a Princeton astrophysicist and director of the Center for Computational Astrophysics , tells Mental Floss . “ So they ’re linked together — but this is a Gallus gallus - and - orchis question that we do n’t know the answer to . ”
Another motivating for studying mordant holes is to mold whether Einstein ’s possibility of gravity , cognise as world-wide relativity , correctly betoken the observed physical science . The possibility , which turned 100last year , has so far passed every test thrown at it — but it has yet to be test in the alien environment adjacent to a black hole event horizon , with its extremist - impregnable gravitational field . “ You ’re poke into a novel authorities — and whenever you ’re in a new regime , you could be in for a surprise , ” Spergel says .
The astronomers work on the EHT wo n’t see the fruits of their labors right out : Each of the readiness in the array enter about 500 terabyte of datum during this natural spring ’s observing rivulet — far too much to be handily mail over the net . So the data point is being institutionalise the old - fashioned manner , by shipping bulky campaign via FedEx to the EHT ’s two processing center , place in Westford , Massachusetts and in Bonn , Germany . ( That does n’t include the disks from the South Pole Telescope ; they ’ll be embark later in the year , when plane can enter the website after the south-polar winter . ) Then the datum involve to be processed , which will take some six to eight months .
inquire if he was feeling tense , Marrone replied that “ prediction ” was a better word ; after all the testing he and his colleagues have done , he ’s passably confident that the EHT has delivered the goodness . “ I ’d like to know what we ’ve got in those data , ” he said . “ But it ’s going to be a long wait . ”
