Atmosphere of habitable world around K-type star

I'm trying to work out the parameters of my planet, using the spreadsheets that Artifexian has developed (particularly this Planet Calculator and this Atmosphere Calculator) as a guide. In order for this planet to have liquid water at the surface, it requires its atmosphere to provide twice the insulation of Earth's atmosphere; that is, the atmosphere needs to raise the surface temperature by ~65 K instead of the ~33 K that the Earth's atmosphere does.

What kind of atmospheric composition could achieve this?

At the moment I've got an atmosphere comprising 2.349% Ne, 73.446% N2, 16.344% O2, 7.574% Ar, and 0.215% CO2 by unit volume of dry air. Water vapour content sits at around 0.8"“1% averaged over the entire atmosphere. This atmospheric composition is approximately 0.1% denser than Earth's, but I essentially pulled these numbers out of a hat and I'd like to do slightly better than that. Ideally the air pressure at sea level would be no more than about 1.4 Earth's.

Other system details:

• Sun is a K1.2V
• Planet orbits its sun at a distance of 0.871 AU
• Planet radius, mass, and density are 0.956, 0.862 and 0.986 of Earth

posted about 5 years ago

Robbie‭

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