OTD in 2019: Revisit the photo-release of 1st directly imaged supermassive black hole

It was on this day in 2019, when international collaboration between European Sourn Observatory (ESO), ALMA and APEX fructified to produce first-ever directed photograph of a supermassive black hole. Located at center of Messier 87 galaxy, supermassive black hole resides 55 million light-years from Earth and has a mass 6.5 billion times that of Sun. According to ESO, black hole was photographed using Event Horizon Telescope (EHT)-- a planet-scale array of eight ground-based rio telescopes-- and breakthrough was anunced in a series of six papers published in  Astrophysical Journal Letters.

astromers were able to have a relatively clear look at black hole using a technique called very-long-baseline interferometry (VLBI). It is a technique that synchronises telescope facilities around world and exploits rotation of our planet to form one huge Earth-size telescope. Interestingly, this technique allowed a resolution clear eugh to re a newspaper in New York from a cafe in Paris.

Over 200 hundred researchers overcome formidable challenge

"We have taken first picture of a black hole. This is an extraordinary scientific feat accomplished by a team of more than 200 researchers", se were words of EHT project director Sheperd S. Doeleman of Center for Astrophysics- Harvard & Smithsonian. Photographing supermassive black hole was a formidable challenge for astromers since y h to upgre and connect a worldwide network of eight pre-existing telescopes deployed at difficult high-altitude locations. 

Paul T.P. Ho, EHT Board member h said in an ESO statement, "Once we were sure we h imd show, we could compare our observations to extensive computer models that include physics of warped , superheated matter and strong magnetic fields. Many of features of observed im match our oretical understanding surprisingly well". 

As for measuring mass of supermassive black hole, astromers said that y were able to do so by studying bright area around it. y explained that a black hole creates a dark region similar to a show when immersed in a bright region, like a disc of glowing gas. "This show, caused by gravitational bending and capture of light by event horizon, reveals a lot about nature of se fascinating objects and has allowed us to measure ermous mass of M87’s black hole", astromer Hei Falcke of Rboud University said.