Surprise! Black-Hole Instrument Finds One Star That's Actually Two (Video)

Trapezium Cluster GRAVITY
As part of the first observations with the new GRAVITY instrument the team looked closely at the bright, young stars known as the Trapezium Cluster, located in the heart of the Orion star-forming region. (Image credit: ESO/GRAVITY consortium/NASA/ESA/M. McCaughrean)

A new instrument designed to study the extreme environments around black holes has observed the heavens for the first time — and made a surprising discovery.

The Gravity instrument, which researchers recently installed at the European Southern Observatory's (ESO) Very Large Telescope (VLT) in northern Chile, has achieved "first light," eyeing the Trapezium Cluster, a well-studied group of bright, young stars in the Orion star-forming region.

During the course of this test, Gravity — which combines the light gathered by multiple telescopes to form a virtual observatory up to 660 feet (200 meters) wide, using a method called interferometry — found that the star Theta Orionis F is actually two separate stars, the researchers said. They also created a video to zoom in on the double star revealed by Gravity

Zooming in on black holes is the main mission for the newly installed instrument GRAVITY at ESO’s Very Large Telescope in Chile. During its first observations, GRAVITY successfully combined starlight using all four Auxiliary Telescopes. (Image credit: ESO/GRAVITY consortium)

"During its first light, and for the first time in the history of long baseline interferometry in optical astronomy, Gravity could make exposures of several minutes — more than a hundred times longer than [was] previously possible," Frank Eisenhauer, of the Max Planck Institute for Extraterrestrial Physics in Germany, said in a statement.

Zooming in on black holes is the main mission for the newly installed instrument GRAVITY at ESO’s Very Large Telescope in Chile. During its first observations, GRAVITY successfully combined starlight using all four Auxiliary Telescopes. This picture shows some of the large and international GRAVITY team during initial observations at the Paranal Observatory. (Image credit: ESO/GRAVITY consortium)

"Gravity will open optical interferometry to observations of much fainter objects, and push the sensitivity and accuracy of high angular resolution astronomy to new limits, far beyond what is currently possible," Eisenhauer added.Gravity's main task will involve studying what happens near supermassive black holes — those that lie at the hearts of other galaxies, as well as the one at the center of our own Milky Way. (Black holes exert a tremendous gravitational pull, which explains the instrument's name.)

Scientists will also use Gravity to probe exoplanets, image the surfaces of stars, and examine mass accretions and jets — phenomena that occur near newborn stars and supermassive black holes, the researchers said.

During the recent tests, Gravity was hooked up to the VLT's four 5.9-foot (1.8 m) Auxiliary Telescopes. Researchers plan further trials using the four 26.2-foot (8 m) VLT Unit Telescopes later this year, ESO officials said.

The Max Planck Institute for Extraterrestrial Physics leads the Gravity consortium, which includes six other partner organizations in France, Germany and Portugal.

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Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: