At the centre of our spiral-shaped Milky Way galaxy is a beast — a supermassive black hole 4-million times the mass of our sun and consuming any material, including gas, dust and stars, straying within its immense gravitational pull.

Scientists have been using the Event Horizon Telescope (EHT), a global network of observatories working collectively to observe radio sources associated with black holes, to study this denizen and have set an announcement for Thursday that signals they may finally have secured an image of it. The black hole is called Sagittarius A*, or Sgr A*.

The researchers involved in this international collaboration have declined to disclose the nature of their announcement ahead of scheduled news conferences, but issued a media release calling it a “groundbreaking result on the centre of our galaxy”...