May
13

Unveiling our Galaxy’s Black Hole

Yesterday, scientists at the Smithsonian Astrophysical Observatory, in collaboration with hundreds of scientists across the world, unveiled the first picture of the black hole at the center of our Milky Way galaxy. 

Black Hole
This is the first image of Sagittarius A* (or Sgr A* for short), the supermassive black hole at the center of our galaxy. It’s the first direct visual evidence of the presence of this black hole. It was captured by the Event Horizon Telescope (EHT), an array which linked together eight existing radio observatories across the planet to form a single “Earth-sized” virtual telescope. The telescope is named after the “event horizon,” the boundary of the black hole beyond which no light can escape. Although we cannot see the event horizon itself, because it cannot emit light, glowing gas orbiting around the black hole reveals a telltale signature: a dark central region (called a “shadow”) surrounded by a bright ring-like structure. The new view captures light bent by the powerful gravity of the black hole, which is four million times more massive than our Sun. The image of the Sgr A* black hole is an average of the different images the EHT Collaboration has extracted from its 2017 observations. EHT Collaboration

This extraordinary endeavor began more than a decade ago when Smithsonian astrophysicist Sheperd Doeleman founded the Event Horizon Telescope, a planet-spanning telescope capable of capturing the invisible.

In 2019, the Smithsonian was honored to be associated with the release of the first-ever image of a black hole, which paved the way to today’s announcement.

These discoveries open up new possibilities for the study of black holes and our understanding of the cosmos. 

I want to congratulate the many individuals at SAO who have contributed to this exciting development. I would also like to mention that our Smithsonian facility in Hawaii, the Submillimeter Array, was instrumental in making these first images of black holes. 

If you would like further information about this extraordinary result, I encourage you to view the discussion moderated by Ellen Stofan, Under Secretary for Science and Research, featuring SAO scientists who contributed to this achievement. A recording of yesterday’s live stream is available on Torch here and on SAO’s YouTube page

I think I speak for us all when I say that I am proud to be a part of the Smithsonian every day, but especially on momentous days like yesterday.

I look forward to our next great discovery.

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Posted: 13 May 2022
About the Author:

Lonnie G. Bunch III is the 14th Secretary of the Smithsonian Institution. He was the founding director of the Smithsonian’s National Museum of African American History and Culture and is the first historian to be Secretary of the Institution.