[1] The TESS-Keck Survey collaboration performed radial velocity follow-up observations for nearly 2 years with the Automated Planet Finder and Keck I.

[1] The planet does not orbit inside the habitable zone, despite this close resemblance in semi-major axis.

The discovery team inferred that TOI-2180 b is enriched in metals by a factor of about 5 compared to its host star.

[1] The exoplanet is a poor target for transmission spectroscopy because of its high surface gravity and the large radius of the host star.

The large radius of the star causes a relative shallow transit depth of about 0.5%.

[1][note 1] Because TOI-2180 is slightly evolved, it had a habitable zone closer to the star in the past.

[1][8][note 2] The radial velocity monitoring also showed acceleration of TOI-2180 b due to an outer planet or low-mass star in the system.

[1] A later analysis of RV data has shown that an outer companion has an orbital period of 1558+68−19 days, an eccentricity of about 0.31 and a minimum mass of 3.94+0.27−0.22 MJ, making it likely a giant planet.