# Planet Search with the Keck/NIRC2 Vortex Coronagraph in Ms-band for Vega

**Authors:** Bin B. Ren, Nicole L. Wallack, Spencer A. Hurt, Dimitri Mawet, Aarynn L. Carter, Daniel Echeverri, Jorge Llop-Sayson, Tiffany Meshkat, Rebecca Oppenheimer, Jonathan Aguilar, Eric Cady, Elodie Choquet, Garreth Ruane, Gautum Vasisht, Marie Ygouf  
**arXiv:** [2301.07714](https://arxiv.org/abs/2301.07714)  
**Date:** 2023-01-18  
**Summary page:** https://www.summarizepaper.com/en/paper/2301.07714v1/

## Key points

- Direct imaging observations have revolutionized the search for exoplanets, particularly in systems with circumstellar disks that exhibit gaps indicating the presence of planetary perturbers.
- Vega is an ideal target for planet imaging efforts due to its nearly face-on planetary system and two-belt debris disk structure.
- The authors used the vector vortex coronagraph on Keck/NIRC2 in Ms-band at 4.67 $\mu$m to report planet detection limits from 1 au to 22 au for Vega with an on-target time of 1.8 h.
- The results show a three Jupiter mass limit exterior to 12 au which is almost ten times deeper than previous studies.
- Companions more massive than ~8 Jupiter mass can be confidently ruled out from 22 au down to 0.1 au for Vega by combining these findings with existing radial velocity studies.
- This combined approach reaches planet detection limits down to ~2-3 Jupiter mass using radial velocity and direct imaging inside and outside ~4 au respectively.
- These multi-Jupiter mass detection limits are expected to complement future observations using the James Webb Space Telescope (JWST) in obtaining a more comprehensive understanding of the planetary system configuration around Vega.
- Gaps in circumstellar disks can provide crucial information about exoplanet systems, emphasizing the importance of direct imaging observations in detecting exoplanets beyond our solar system.
- The results obtained from this research will contribute towards advancing our knowledge about exoplanetary systems and their formation mechanisms while paving the way for further discoveries through future observations using advanced telescopes like JWST.

## Summary

The search for exoplanets has been revolutionized by the use of direct imaging observations, particularly in systems with circumstellar disks that exhibit gaps indicating the presence of planetary perturbers. Vega, one of the closest and brightest stars to our Sun, is known to host a two-belt debris disk structure and its nearly face-on planetary system makes it an ideal target for planet imaging efforts. In this study, the authors used the vector vortex coronagraph on Keck/NIRC2 in Ms-band at 4.67 $\mu$m to report planet detection limits from 1 au to 22 au for Vega with an on-target time of 1.8 h. The results show a three Jupiter mass limit exterior to 12 au which is almost ten times deeper than previous studies. By combining these findings with existing radial velocity studies, companions more massive than ~8 Jupiter mass can be confidently ruled out from 22 au down to 0.1 au for Vega. Moreover, this combined approach reaches planet detection limits down to ~2-3 Jupiter mass using radial velocity and direct imaging inside and outside ~4 au respectively. These multi-Jupiter mass detection limits are expected to complement future observations using the James Webb Space Telescope (JWST) in obtaining a more comprehensive understanding of the planetary system configuration around Vega. The study highlights how gaps in circumstellar disks can provide crucial information about exoplanet systems and emphasizes the importance of direct imaging observations in detecting exoplanets beyond our solar system. The results obtained from this research will contribute towards advancing our knowledge about exoplanetary systems and their formation mechanisms while paving the way for further discoveries through future observations using advanced telescopes like JWST.