#ab aurigae

We’ve been watching a failed star turn into a giant planet | Ars Technica

For the first time, astronomers may have seen direct evidence of a planet forming around a young star.

A spiral disk of gas and dust surrounding the star AB Aurigae contains a small S-shaped twist near the spiral’s center, infrared telescope images show.

That twist “is the precise spot where a new planet must be forming,” says astrophysicist Emmanuel Di Folco of the University of Bordeaux in France.

Previously, astronomers have seen gaps (SN: 11/6/14) and large-scale spirals (SN: 6/14/18) that are thought to be created by unseen planets in disks of gas and dust around young stars. Theories of how planets coalesce and gather material from these disks predict that planets’ motions would further twist the gas around them like swirling skirts, pinpointing a planet’s location (SN: 5/11/18).

Now, Di Folco and colleagues have used infrared observations from the Atacama Large Millimeter/submillimeter Array and the Very Large Telescope, both in Chile, to find a spiral and zero in on one such S-shaped twist around AB Aurigae. The team describes its findings in the May Astronomy & Astrophysics.

A close-up of the disk of gas and dust (seen here in infrared light) around the young star AB Aurigae (left) reveals a bright knot (right, circled in white) where astronomers think a planet is coalescing. For scale, the blue circle represents the size of Neptune’s orbit. A. BOCCALETTI ET AL/ASTRONOMY & ASTROPHYSICS 2020, ESO

“It was amazing,” Di Folco says. “It was exactly as we were expecting from the theoretical predictions of planet formation.”

The star, about 520 light-years away in the constellation Auriga, is just 4 million years old, about one one-thousandths of the age of the sun. “It’s really a baby,” Di Folco says.

The potential planet’s exact mass is not known, but it probably would have to be a gas giant like Jupiter rather than a rocky planet like Earth to make such big waves in the disk. And it might not be alone — there’s a hint of another planet near the disk’s outer edge.

Scientists have spotted what appears to be evidence of a planet forming near a young star. And they’ve got pictures.

Explainer: What is a planet?

The star is AB Aurigae. It’s 520 light-years away in the constellation Auriga. (Auriga is Latin for “the chariot driver,” which the constellation is supposed to depict.) At just 4 million years old, AB Aurigae is about one-thousandth the age of our sun. “It’s really a baby,” Emmanuel Di Folco says. He works at the University of Bordeaux in France. As an astrophysicist, he studies the interactions of mass and energy within the cosmos.

The star AB Aurigae and gas spiraling around it (left). Close-up of the swirling gas and dust (right) shows extra-bright knot (circled in white). That’s where a planet appears to be forming. For scale, blue circle (bottom, right) represents the size of Neptune’s orbit. CREDIT: A. BOCCALETTI ET AL/ASTRONOMY & ASTROPHYSICS 2020, ESO

Astronomers have seen gaps and large-scale spirals around young stars before. They thought these must have been created by unseen exoplanets — planets outside of our solar system.

Developing planets pull in material from nearby space. In the process, their motions twist the gas around them like swirling skirts. Scientists can hunt for these swirls to pinpoint a planet’s location.

Di Folco and his colleagues used observations from two telescopes in Chile: the Atacama Large Millimeter/submillimeter Array and the Very Large Telescope. These scout for infrared light — a type the human eye can’t see. Images from the telescopes show a spiral disk of gas and dust surrounding AB Aurigae. Near the spiral’s center was a small S-shaped twist.

The star AB Aurigae is about 520 light-years away from Earth. It’s in the constellation Auriga. Zooming in close, scientists could see a spiral shape of dust and gas. An S-shaped region near the spiral’s center is where a new planet appears to be coming together. 

That twist “is the precise spot where a new planet must be forming,” says Di Folco. He and his colleagues described their find May 20 in Astronomy & Astrophysics. “It was amazing,” Di Folco says. “It was exactly as we were expecting.”

Prenatale protoplaneet zet modellen voor planeetvorming op zijn kop

Foto van AB Aurigae en z’n protoplanetaire palneet AB Aur b. De ster zelf hebben ze gemaskeerd. Credit: T. Currie/Subaru Telescope Een internationaal onderzoeksteam heeft een nieuwe planeet ontdekt die zo jong is dat hij nog uit de spreekwoordelijke baarmoeder van materie moet komen waar hij zich vormt. Dit is de jongste protoplaneet die tot nu toe is ontdekt. De locatie en de omringende patronen…

Prenatale protoplaneet zet modellen voor planeetvorming op zijn kop

Foto van AB Aurigae en z’n protoplanetaire palneet AB Aur b. De ster zelf hebben ze gemaskeerd. Credit: T. Currie/Subaru Telescope Een internationaal onderzoeksteam heeft een nieuwe planeet ontdekt die zo jong is dat hij nog uit de spreekwoordelijke baarmoeder van materie moet komen waar hij zich vormt. Dit is de jongste protoplaneet die tot nu toe is ontdekt. De locatie en de omringende patronen…