🪐 Astronomers Just Watched a Planet Being Built

We know surprisingly well how planets should form.

The problem is that the crucial parts of the process happen hundreds of light-years away, on scales so tiny that astronomers have mostly had to reconstruct them from simulations and indirect clues.

Now they have caught the process in action.

Using Atacama Large Millimeter/submillimeter Array, astronomers imaged gas moving around WISPIT 2b, a newborn planet about 430 light-years from Earth.

It is a monster in the making: roughly five times the mass of Jupiter, orbiting inside the disk of gas and dust from which its planetary system is still emerging.

And around the planet, the gas is doing something remarkable.

On one side of WISPIT 2b it is moving toward us; on the other, away from us.

Together, those motions reveal a swirl of gas around the growing planet — exactly the kind of interaction predicted by simulations of planet formation, but never directly observed around a known protoplanet before.

The system is unusually valuable because astronomers can now see essentially every major piece of the process at once:

the enormous protoplanetary disk, the planet itself, hydrogen emission showing that WISPIT 2b is still accreting material, the gap it has carved through the disk — and now the surrounding gas responding directly to the planet.

A second young planet, WISPIT 2c, is also reshaping the system by carving out a larger cavity. And at the center, astronomers recently discovered that there isn’t even one star.

There are two.

The scale of the observation is extraordinary.

At WISPIT 2’s distance, resolving a structure the size of Earth’s orbit around the Sun is roughly equivalent to reading a normal book from five kilometers away.

For decades, simulations have shown us beautiful animations of planets growing inside swirling disks.

Now nature has finally provided the footage.

We are beginning to watch solar systems assemble in real time.

#Space #Astronomy #Exoplanets #PlanetFormation #ALMA #WISPIT2 #Science

https://www.mpg.de/26990768/astronomers-produce-the-first-complete-picture-of-gas-planet-formation-in-action