Historic Discovery: Scientists Observe a 'Baby' Planet During Its Birth for the First Time Ever

An international team of astronomers, using an advanced observational tool, has captured the first direct visual evidence of a protoplanet as it carves a giant gap in the dust disk surrounding a young star, in an unprecedented discovery that solves a mystery that has persisted for decades in astronomy.

This discovery, published in two research papers in the The Astrophysical Journal Letters, confirms prevailing theories about how planets form, which had previously been mere hypotheses.

Scientists have long observed mysterious gaps in protoplanetary disks around newly born stars, hypothesizing that forming planets are responsible for creating them. However, no one has been able to directly observe these 'baby' planets due to their small size and faint light compared to the brightness of their parent star.

Astronomer Laird Close from the University of Arizona says: "Dozens of theoretical papers have been written discussing how these observed gaps in the disks are caused by protoplanets, but no one has been able to find conclusive evidence until today. It has been a real source of debate in scientific circles and astronomical literature: the existence of these deep gaps while we are unable to observe the faint planets lurking within them. Many have doubted the ability of protoplanets to create these gaps, but we now know, definitively, that they can."

This dilemma was solved by searching for a unique light signature emitted by the planets as they form. During the growth process, these planets consume hydrogen gas from their surroundings. When this gas falls onto the developing planet, it forms extremely hot plasma that emits a distinctive light known as "H-alpha emission".

To search for this signature, the international team designed the MagAO-X instrument, an advanced adaptive optics system mounted on the Magellan telescope in Chile, specifically designed for this purpose.

Close explains the mechanism: "As planets form and grow, they consume hydrogen gas from their immediate surroundings. When this gas rushes to fall onto the developing planet, like a massive waterfall from outer space, it collides with the surface, creating extremely hot plasma, which in turn emits this distinctive light, H-alpha. The MagAO-X system is specifically designed to search for hydrogen gas as it falls onto these small protoplanets, allowing us to detect them."

The study focused on the star TYC-5709-354-1 (also known as WISPIT-2), a 'baby' star similar to the sun located about 434 light-years away. Previous observations had revealed a rotating disk around it with a "stunningly massive" gap.

By combining data from the MagAO-X instrument with infrared observations from the Very Large Telescope (VLT), scientists confirmed that the protoplanet, named WISPIT-2b, is clearly sitting in the middle of that gap. The planet WISPIT-2b has a massive mass of about 5 times that of Jupiter and is located 54 astronomical units from its star (which is 54 times the distance between the Earth and the Sun), making it very far from the center of its system.

This discovery gives scientists a rare glimpse into how our solar system may have looked while forming around a 'baby sun', opening a new era in understanding the planet formation process.