These Images of Two Planetary Formations Offer a Unique View of Our Past

Last year, we reported that the star system WISPIT 2 was home to some amazing visual features, most notably a protoplanet carving a visible trench in the system’s disk of rocks and gas. That protoplanet was named WISPIT 2b, and its discovery was hailed as a major breakthrough—but there were some small cracks in the system, too.

It has long been thought that most or all such lines are evidence of protoplanets still forming, but only a few like WISPIT 2b have been observed to prove it. Now, a new study published in The Astrophysical Journal Letters confirms that some bodies are actually building in WISPIT 2.

Specifically, they introduce us to a brand new protoplanet: WISPIT 2c.

Apart from other discoveries of protoplanets that record a path through a gaseous disc, this marks the first time that two such planets have been found in the same system. The only other system in which two planets forming planets were found was PDS 70, but it did not have a useful belt with an extended disc, providing little evidence for study.

Using WISPIT 2, astronomers can, for the first time, see the ways in which complex systems resemble our own. The interaction between multiple forming bodies, each absorbing gas from a homogeneous cloud, is difficult to model in pure theory; here, astrologers have room to test theories against actual evidence.

WISPIT 2c itself orbits about a quarter as far from WISPIT 2 as WISPIT 2b, meaning it is about 15 times farther from its star than Earth is from the Sun. WISPIT 2c is also about twice the mass of 2b, although it has been difficult to observe due to its small orbit and proximity to the star. It was taken with the Very Large Telescope (VLT) and the accompanying VLT Interferometer.

This PDS70 image also shows evidence of many protoplanets, but in a way that is less useful for reading.
Credit: NAOJ

For reference, exoplanets are named in such a way that the star is apparently WISPIT 2a, although we don’t usually write that, giving the first discovered exoplanet the designation ‘b.’ Order refers to availability, not physical placement within the system.

Now, even a cursory glance will tell you that the WISPIT 2 system has more than two bands in it, and possibly more than two protoplanets. The team is confident that these represent other protoplanets and that they, too, will one day be directly observed.

Finally, there are many unanswered questions about the composition of our solar system that can be cleared up with a good, accurate position to study. Why do our planets have such different compositions? How did gas giants like Jupiter form? Why do the planets in our system revolve in such neat, orderly rings?

Learning systems like WISPIT 2 can help provide answers to these questions and more.