Wiretapping a Star: How a Naked Planet Helps Find Air ⚡ экспресс
The goal is to determine whether planet TRAPPIST-1 e has an Earth-type atmosphere with a moderate molecular weight and CO₂ content. This uses a multi-cycle JWST program: close transits of the airless TRAPPIST-1 b allow model-independent correction of stellar contamination. Modeling shows that 15 observations of close transits would detect such an atmosphere with a confidence of Δln Z ≥ 5, provided the correction is successful. The first three observations revealed that powerful stellar flares violate the assumption of a constant star between transits, reducing correction efficiency. The best transit demonstrates removal of stellar contamination thanks to increased preference for a flat line compared to the original TRAPPIST-1 e spectrum, but highlights how minor assumptions in data analysis can be greatly amplified when searching for weak atmospheric signals. This effect is exacerbated when combining signals from multiple planets, which is important to consider in future searches.
Eavesdropping on a distant planet's atmosphere is hampered by the star's noise. In the TRAPPIST-1 system, astronomers used a planet-"bug": TRAPPIST-1 b — an airless neighbor that records only the interference. By subtracting this recording from the signal of planet TRAPPIST-1 e, we can isolate the pure voice of its air.
Initial observations by James Webb proved the idea works: on quiet days, no traces of air are seen, as expected. But the star's whims continue a game of broken telephone. The search for an atmosphere on TRAPPIST-1 e goes on — hoping to catch the star in a good mood.
🎯 The TRAPPIST-1 system is so compact that all its planets could fit inside Mercury's orbit. A year on TRAPPIST-1 e lasts just 6 Earth days.