Prenatal protoplanet upends planet formation models

An international research team has discovered a new planet so young that it has yet to emerge from the womb of matter where it is forming. This is the youngest protoplanet discovered to date.

It's location and the surrounding patterns of matter suggest that an alternative method of planet formation may be at work. This discovery could help to explain the histories and features of extrasolar planets seen around other stars.

In the standard model of planet formation, a large Jupiter-like gas planet starts as a rocky core in a protoplanetary disk around a young star. This core then accretes gas from the disk, growing into a giant planet.

While this model works well for the planets in the Solar System, it has trouble explaining exoplanets which have been discovered around other stars at distances much larger than the orbit of Neptune, the outermost Solar System planet.

Rocky cores aren't expected to form far away from the central star, so core accretion can't drive distant planet formation. One theory holds that outlying planets form close to the central star and move outwards.

But new observations using an extreme adaptive optics system which allows the Subaru Telescope to directly image faint objects close to brighter stars show what appears to be a protoplanet in the process of forming directly at a distance of 93 au: over three times the distance between the Sun and Neptune.

Analysis of this object, named AB Aur b, shows that a simple model of starlight reflected from an anomaly in the disk can't reproduce the observations; but neither can a model of a naked planet. The best fit models indicate that AB Aur b is a protoplanet so young that it is still forming in a womb of matter in the protoplanetary disk.

Nearby spiral structures in the disk match models where a planet forms directly from the gravitational collapse of the surrounding matter. This discovery has profound implications for explaining the many observed outlying exoplanets and the overall theoretical model of planet formation.

"This study sheds new light on our understanding of the different ways that planets form," says Thayne Currie, lead author of the discovery paper.

Research Report: "Images of embedded Jovian planet formation at a wide separation around AB Aurigae"

Related Links
NAOJ
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Hubble finds a planet forming in an unconventional way
Baltimore MD (SPX) Apr 05, 2022
NASA's Hubble Space Telescope has directly photographed evidence of a Jupiter-like protoplanet forming through what researchers describe as an "intense and violent process." This discovery supports a long-debated theory for how planets like Jupiter form, called "disk instability." The new world under construction is embedded in a protoplanetary disk of dust and gas with distinct spiral structure swirling around surrounding a young star that's estimated to be around 2 million years old. That's abou ... read more