# Direct spectroscopic confirmation of the young embedded proto-planet WISPIT 2c

**Authors:** Chloe Lawlor, Richelle F. van Capelleveen, Guillaume Bourdarot, Christian Ginski, Matthew A. Kenworthy, Tomas Stolker, Laird Close, Alexander J. Bohn, Frank Eisenhauer, Paulo Garcia, Sebastian F. Hönig, Jens Kammerer, Laura Kreidberg, Sylvestre Lacour, Jean-Baptiste Le Bouquin, Eric Mamajek, Mathias Nowak, Thibaut Paumard, Christian Straubmeier, Nienke van der Marel  
**arXiv:** [2603.22085](https://arxiv.org/abs/2603.22085)  
**Date:** 2026-03-23  
**Summary page:** https://www.summarizepaper.com/en/paper/2603.22085v1/

## Key points

- WISPIT 2 is a nearby young star with a multi-ringed disk that has been recently observed.
- Initial observations revealed a gas giant planet, WISPIT 2b, located at a radial separation of 57 au from the host star.
- Further investigations confirmed and characterized a second planet in the system - WISPIT 2c.
- Advanced techniques like VLT/SPHERE H-band imaging and VLTI/GRAVITY K-band interferometric observations were used to study WISPIT 2c.
- WISPIT 2c was detected as a point-like source with CO band-head absorption at 2.3 microns, indicating its composition as a young giant planet.
- Analysis of its spectrum suggested an effective temperature of 1500-2600 K, radius of 0.91-2.2 RJup, and luminosity range of (-3.47)-(-3.63).
- The mass range for WISPIT 2c is estimated to be between 8-12 MJup, making it twice as massive as WISPIT 2b.
- Astrometric measurements ruled out background sources and marginally detected orbital motion for WISPIT 2c.
- Follow-up observations are needed to confirm these findings conclusively.
- The discoveries in the WISPIT 2 system provide insights into planetary formation processes in young stellar environments similar to PDS 70.

## Summary

The WISPIT 2 system is a nearby young star with a multi-ringed disk that has been the focus of recent observations. These observations have unveiled intriguing details about its planetary companions. Initially known to host a ~4.9 MJup gas giant planet, WISPIT 2b, embedded in a large gap at a radial separation of 57 au from the host star, further investigations have now led to the confirmation and characterization of a second planet in the system - WISPIT 2c. Advanced techniques such as VLT/SPHERE H-band dual-polarisation imaging and VLTI/GRAVITY K-band interferometric observations were utilized by researchers to shed light on the properties of WISPIT 2c. The GRAVITY detection of this close-in planet revealed a point-like source with a K-band spectrum displaying CO band-head absorption at 2.3 microns, indicative of its composition as a young giant planet. By extracting and analyzing a medium resolution K-band spectrum of WISPIT 2c, atmospheric model grids were employed to constrain key parameters such as effective temperature, radius, and luminosity. The inferred characteristics of WISPIT 2c point towards an intriguing profile - with an effective temperature ranging from 1500-2600 K, a radius spanning from 0.91-2.2 RJup, and a luminosity falling within the range of (-3.47)-(-3.63). Comparisons with evolutionary tracks suggest that this newly confirmed planet likely falls within the mass range of 8-12 MJup, making it approximately twice as massive as its companion WISPIT 2b. Moreover, astrometric measurements have ruled out any background sources and marginally detected orbital motion for WISPIT 2c. Further follow-up observations are deemed necessary to confirm these findings conclusively. With these discoveries, the WISPIT 2 system now stands as an analog to PDS 70 - offering researchers another laboratory for studying the formation and early evolution of multi-planet systems within their natal disks. This expanded understanding opens up new avenues for exploring planetary formation processes in young stellar environments like WISPIT 2.