James Webb Space Telescope could determine if nearby exoplanet is habitable

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The exoplanet LP 890-9c resides near the inner edge of its star's habitable zone, and if conditions are favorable it could potentially support liquid water and life.

James Webb Space Telescope could determine if nearby exoplanet is habitable : Read more

 

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The article states: "Looking at this planet will tell us what's happening on the inner edge of the habitable zone — how long a rocky planet can maintain habitability when it starts to get hot," Kaltenegger said in a statement.

Kaltenegger's team modeled the planet based on its mass and radius, both of which astronomers have measured. The models also incorporated assumptions about the planet's chemical makeup, its surface temperature and pressure, the depth of its atmosphere and the amount of cloud present. These latter factors are currently unknown. Indeed, the planet could be airless and cratered for all we know, which is a strong possibility given that red dwarfs are often prone to violent flares that could strip an atmosphere from a nearby orbiting world.

The team produced five different models describing what LP 890-9c might be like. These ranged from an Earth-like planet but hotter, through various degrees of atmospheric water vapor content and levels of greenhouse effects, culminating in the final model resembling hellish Venus with its suffocating carbon dioxide."

My note. LP 890-9 c is at least 2.5 earth masses and likely larger radius as the paper cited shows. "We assign the planet’s white light radius (1.37 R⊕) to the surface and compute a new reference radius at a pressure of 1 mbar and, in lieu of a mass measurement, adopt the predicted median mass of 2.5 M⊕(Delrez et al. 2022) from a mass–radius relationship (Chen & Kipping 2017).", https://academic.oup.com/mnrasl/article/524/1/L5/7198492?searchresult=1&login=false

It remains to be seen just how reliable any of the models are for this exoplanet. This site shows properties too, http://exoplanet.eu/catalog/lp_890-9_c/, but the mass is much larger like larger than Neptune (could be accurate or an error). This reference indicates masses remain to be determined. https://arxiv.org/abs/2209.02831, "...Although the masses of the two planets remain to be measured, we estimated their potential for atmospheric characterisation via transmission spectroscopy using a mass-radius relationship and found that, after the TRAPPIST-1 planets, LP 890-9c is the second-most favourable habitable-zone terrestrial planet known so far. The discovery of this remarkable system offers another rare opportunity to study temperate terrestrial planets around our smallest and coolest neighbours."