A temperate super-Jupiter imaged with JWST in the mid-infrared

Area of Science:

• Astronomy and Astrophysics
• Exoplanetary Science
• Planet Formation and Evolution

Background:

• Directly imaged exoplanets are typically young (<500 Myr).
• Epsilon Indi A is a Sun-like star with evidence suggesting a giant planet.
• Previous studies proposed a giant planet based on radial velocity and astrometric data.

Purpose of the Study:

• To directly image and characterize the giant exoplanet orbiting Epsilon Indi A.
• To verify and refine the properties of the claimed exoplanet.
• To investigate the atmospheric composition and thermal evolution of the exoplanet.

Main Methods:

• Utilized James Webb Space Telescope (JWST) coronagraphic imaging.
• Analyzed data at infrared wavelengths (10.65 and 15.50 µm) and non-detections (3.5-5.0 µm).
• Compared observational data with theoretical thermal evolution models.

Main Results:

• Directly imaged a giant exoplanet consistent with prior radial and astrometric measurements.
• Determined the planet's temperature to be approximately 275 K.
• Observed atmospheric opacity between 3.5-5.0 µm, suggesting a high-metallicity, high carbon-to-oxygen ratio.

Conclusions:

• The findings confirm the existence of a giant planet around Epsilon Indi A.
• The planet's properties align with theoretical models at previously untested temperatures.
• The data suggest this is likely the sole giant planet in the Epsilon Indi A system.