An international astronomical project that includes Taiwan’s Academia Sinica on Thursday released the first-ever image documenting the existence of a massive black hole at the center of the Milky Way.
Astronomers believe nearly all galaxies have giant black holes at their bustling and crowded center, where light and matter cannot escape, making it extremely hard to capture images of them. Light is bent and twisted around by gravity, as it is sucked into the abyss, along with superheated gas and dust.
The colorized image unveiled on Thursday is from an international consortium comprising 13 research units from around the world. The Event Horizon Telescope (EHT), a collection of eight synchronized radio telescopes around the world, captured the image of Sagittarius A*, a black hole at the center of our galaxy about 27,000 light years away.
Photo: Reuters / EHT Collaboration /National Science Foundation
University of Arizona astrophysics professor Feryal Ozel described it as a “gentle giant” while announcing the breakthrough along with other astronomers involved in the project.
Academia Sinica President James Liao (廖俊智) told a press conference held simultaneously in Taipei that the image offered direct proof of earlier scientific work that provided evidence of a black hole at the center of our galaxy.
“With Academia Sinica as one of the 13 members of the EHT, we have again shown Taiwan’s continued role in the world’s most important scientific discoveries,” he added.
The picture also confirms Albert Einstein’s general theory of relativity: The black hole is precisely the size that Einstein’s equations dictate. It is about the size of the orbit of Mercury around the sun.
Black holes gobble up galactic material, but Ozel said this one is “eating very little.”
It is equivalent to a person eating a single grain of rice over millions of years, another astronomer said.
University of California, Los Angeles astronomy professor Andrea Ghez, not part of the telescope team, but who earned a Nobel Prize for the discovery of the Milky Way’s black hole in the 1990s, said the image of “my baby” is exactly how it should be — an eerie-looking orange-red ring with utter blackness in the middle.
Scientists had expected the Milky Way’s black hole to be more violent, especially since the only other image from another galaxy shows a far bigger and more active black hole.
“It is the cowardly lion of black holes,” said Event Horizon Telescope project scientist Geoffrey Bower, a research fellow at Academia Sinica’s Institute of Astronomy and Astrophysics.
Because the black hole “is on a starvation diet,” little material is falling into the center, and that allows astronomers to gaze deeper, he said.
The Milky Way black hole is probably more typical of what is at the center of most galaxies, “just sitting there doing very little,” he added.
It is incredibly hot, trillions of degrees, Ozel said.
The same telescope group released the first black hole image in 2019. The picture was from a galaxy 53 million light years away that is 1,500 times bigger than the one in our galaxy.
To get the picture, the eight telescopes had to coordinate closely “in a process similar to everyone shaking hands with everyone else in the room,” said astronomer Vincent Fish of the Massachusetts Institute of Technology.
Astronomers worked with data collected in 2017 to get the new images. The next step is a movie of one of those two black holes, maybe both, Fish said.
The project cost nearly US$60 million, with US$28 million coming from the US National Science Foundation.
The research results were published in the latest edition of The Astrophysical Journal Letters.
The EHT project, established in 2017, is a global network of radio telescopes — including the Greenland Telescope, the Submillimeter Array (SMA) in Hawaii and the ALMA telescope in Chile — which function together as one large telescope.
Academia Sinica scientists assist in the operation of the project’s telescopes, as well as in image processing and the development of computer simulations.
Additional reporting by CNA
Ninth graders were asked to define “trolling” on this year’s standardized exam, reflecting efforts to make the test better reflect real-life situations. Adjustments to this year’s Comprehensive Assessment Program for Junior High School Students were revealed on Sunday, after the last cohort of students completed the test over the weekend. The Ministry of Education solicited feedback about the test from teachers, who approved of the new question in the English portion. Not only was question No. 20 “very much in line with real-life situations,” but it also used a new style in which students were asked to ascertain the correct dictionary definition based
Taiwan is on alert for monkeypox, a rare viral disease that has caused 87 infections in 11 countries over the past three weeks, the Centers for Disease Control (CDC) said on Saturday. The WHO on Friday convened an emergency session to discuss a sudden outbreak of monkeypox in North America and Europe. Since the beginning of this month, 87 confirmed cases and 28 possible cases have been identified in 11 countries. The countries with the highest case counts are England with 29 cases, and Portugal and Spain with 23 each. Monkeypox is a viral zoonotic disease occurring primarily in the tropical rainforest areas
ADAPTING: The CECC said the policy change would happen this week at the earliest, while PCR testing stations would be used to diagnose people and prescribe drugs The general public would be able to use a positive rapid test result that has been confirmed by a doctor for COVID-19 diagnosis starting later this week at the soonest, the Central Epidemic Command Center (CECC) said yesterday, as it reported 79,441 new local infections and 53 deaths. The center on Saturday announced that it was expanding the rapid test diagnosis policy to people living in indigenous townships and outlying islands, starting today. Minister of Health and Welfare Chen Shih-chung (陳時中), who heads the center, yesterday said the policy might be further expanded to include “all people” this week, at the soonest. He
About 47 percent of people whose deaths were related to COVID-19 this year have died within three days of testing positive, while 33 percent died within three to seven days, the Central Epidemic Command Center (CECC) said yesterday. Centers for Disease Control (CDC) Deputy Director-General Chuang Jen-hsiang (莊人祥), the center’s spokesman, said 66,247 new local cases, 36 imported cases and 40 deaths were confirmed yesterday. As the number of daily confirmed cases has dropped in the past four days, from 90,331 cases on Thursday last week to 66,247 cases yesterday, the center was asked if Taiwan has reached the peak of a