WISPIT 2 is only the second known system, after PDS 70, where two planets have been directly observed forming around their host star. However, unlike PDS 70, WISPIT 2 has a very extensive protoplanetary disk, featuring material-depleted channels and distinctive rings.
Thanks to these observations, astronomers hope to better understand how young planetary systems evolve into mature systems, such as our own.
The first nascent planet discovered in this system—named WISPIT 2b—was detected last year; it has a mass nearly five times that of Jupiter and orbits the central star at a distance equivalent to about 60 times the distance between Earth and the Sun. After the identification of an additional object near the star, measurements taken with ESO’s Very Large Telescope (VLT) and the VLT Interferometer (VLTI) confirmed its planetary nature. The new planet—named WISPIT 2c—is four times closer to the central star and twice as massive as WISPIT 2b. Both planets are gas giants, similar to the outer planets of our Solar System.
To confirm the existence of WISPIT 2c, the team used ESO’s VLT SPHERE instrument, which captured an image of the object. The team then used the VLTI’s GRAVITY+ instrument to confirm that the object was indeed a planet.
“The discovery of this new world in the making fully demonstrates the exceptional capabilities of the latest-generation instruments on ESO’s telescopes. Typically, the combined use of SPHERE and GRAVITY+, two instruments to which the LIRA at the Paris Observatory – PSL contributed, now makes it possible to detect and characterize planets extremely close to their star with unprecedented precision.” explains Sylvestre Lacour, CNRS research director at the Paris Observatory – PSL and co-author of the study.
The two planets of WISPIT 2 appear in clearly defined clearings within the disk of dust and gas surrounding the young star. These clearings are the result of each planet’s formation process: particles in the disk accumulate, their gravity attracting more material until a protoplanet forms. The remaining material, surrounding each clear region, creates distinctive dust rings within the disk.
In addition to the grooves in which these two planets were discovered, researchers have identified a smaller groove, located further out in the WISPIT 2 disk. This could be a sign of a third planet in formation, likely with a mass comparable to Saturn’s, as suggested by its smaller size and shallower depth within the groove. The team plans to continue observations and hopes that with ESO’s future Extremely Large Telescope (ELT), it will be possible to directly detect this object.
Reference
Direct spectroscopic confirmation of the young embedded proto-planet WISPIT 2c
On the same topic, the press release published on the ESO website:
"A Solar System in the making? Two planets spotted forming in disc around young star"