How are planets formed? Baby Jupiter hundreds of light years away offers new clues

How are planets formed? For many years, scientists thought they understood this process by studying the only example we had access to: our own solar system. However, the discovery of planets around distant stars in the 1990s made it clear that the picture was much more complicated than we knew.

In new research, we spotted a hot Jupiter-like gas giant forming around a star about 500 light-years from Earth. This rare shot of a forming planet drawing material from a vast disk of dust and gas swirling around its sun, also in its infancy, has opened a window into mysteries that have intrigued astronomers for years.

A scientific triumph? Scientific investigation of the origins of Earth and other planets in our solar system began in the mid-1700s. Based on the work of Swedish thinker Emanuel Swedenborg, the famous German philosopher Immanuel Kant proposed that the Sun and his small planetary family are all issued from a large rotating primordial cloud; Kant referred to this as Urnebel, German for nebula.

This idea was later refined by the French polymath Pierre Laplace, and it has since undergone many additions and revisions, but modern scientists believe it was basically on the right track. The modern descendant of Kant’s hypothesis, now supplemented by detailed physics, can explain most of the observed features of our solar system. We can now run computer simulations with all the right settings, and a beautiful digital replica of our solar system will emerge. It will have the right types of planets in the right orbits spinning in clockwork order, just like the real thing.

This model is a triumphant synthesis of the threads of geology, chemistry, physics, and astronomy, and it seemed to have covered the basics. Until astronomers confronted it with planets outside our solar system. Beyond the Solar System When the first systems of planets orbiting distant stars were discovered in the mid-1990s, controversy and consternation immediately erupted. The new planets didn’t fit the model at all: it turned out that the rest of the cosmos didn’t care that much about what was happening here around our little sun.

Since then, there has been a dawning realization that there can be different paths to form a planetary system. Among the thousands of planets orbiting other stars that now populate our catalogs, our Sun’s family of planets is even starting to look a bit unusual. Despite this, one of the most basic physical components of the planetary-building machinery that we believe is responsible for the formation of gas giant planets like Jupiter and Saturn has stood the test of time: the idea of core accretion.

Core accretion begins with the gases and microscopic dust grains thought to make up Kant’s typical primordial cloud (which is shaped like a flattened rotating disk with the fledgling star in the center). The dust grains clump together into successively larger grains, then into pebbles, rocks and cascading down to the baby planets or planetesimals. When such a clump becomes large enough, it reaches a tipping point. Gravitational pull now helps the embryonic planet quickly suck in gas, dust and other clumps, clearing its orbital path and carving a circular gap into the disk.

It is one of the iconic triumphs of modern astronomy that exactly the kinds of disc spaces predicted by the theory are now observed and studied in the cosmos. A big crack. However, there are some things base accretion cannot explain. Massive planets have been spotted orbiting far from their host stars in the cold, distant expanses.

According to the central accretion theory, such planets should not exist. They’re too far apart, where the orbits move too slowly to make the planet-building business work. A new gravitational collapse model has been formulated to explain these unexpectedly massive distant planets. The basic idea is that if the primordial disk itself has enough mass, the whole thing can become unstable and collapse to quickly form planets in a loud crunch.

This new image seemed like it could explain outlier planets, but since all known examples were very old (usually billions of years old), this theory remained just a theory. Until now. A planet is born Last year, our colleagues and we spotted a massive planet, still forming, around a star some 500 light-years from Earth.

This star, named AB Aurigae, has become famous in astronomy circles for the beautiful, intricate spiral disk that surrounds it. The clumps and waves seen in this disc (and others like it) are consistent with what one would see if gravitational collapse were to occur. But so far, evidence of a forming planet has been missing.

This newly discovered planet dubbed AB Aurigae b is embedded in a thick, swirling halo of dust and gas, amid telltale spirals and waves signifying gravitational collapse. The planet is about 93 times farther from its star than Earth is from the Sun, well outside the region in which the traditional theory of core accretion might explain its formation. This discovery therefore provides strong evidence for the alternative theory of gravitational collapse.

The discovery was made using observations from the Subaru Telescope at Mauna Kea, Hawaii, as well as the Hubble Space Telescope. Fueled by energy from the violent and rapid formation process, the planet is hot enough to glow (about 2000 degrees Celsius). It is this glow that betrays the presence of the planet. At the same time, gas and dust swirling around the forming planet are illuminated by the bluish light of AB Aurigae’s central star.

Bigger and better telescopes This new discovery provides an essential piece of the puzzle of planet formation, but the matter is by no means closed. As our telescopes get bigger and our observing methods become more advanced, we expect to see many more forming planets captured at all stages of their development, as well as fully formed mature planets like Earth. .

And finally, we can hope to answer the big questions: how did such a strange and diverse range of planetary systems form across the galaxy, what are the conditions like on these new worlds, and how did our own little solar system come together? does he fit in with them? ?

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