Astronomers have a trick to study exoplanet atmospheres. By observing the planets as they orbit in front of their host stars, we can study starlight that filters through their atmospheres. For a while, it seemed to work perfectly. But, starting from 2007, astronomers noted that starspots ⁘ cooler, active regions on the stars ⁘ may disturb the transit measurements.
In 2018 and 2019, then-Ph.D. student Benjamin V. Rackham , astrophysicist Mark Giampapa and I published a series of studies showing how darker starspots and brighter, magnetically active stellar regions can seriously mislead exoplanets measurements. We dubbed this problem "the transit light source effect." Most stars are spotted , active and change continuously . Ben, Mark and I showed that these changes alter the signals from exoplanets.
To make things worse, some stars also have water vapor in their upper layers ⁘ often more prominent in starspots than outside of them. That and other gases can confuse astronomers, who may think that they found water vapor in the planet. In our papers ⁘ published three years before the 2021 launch of the James Webb Space Telescope ⁘ we predicted that the Webb cannot reach its full potential.
We sounded the alarm bell. Astronomers realized that we were trying to judge our wine in light of flickering, unstable candles. Pandora breaks with NASA's conventional model. We proposed and built Pandora faster and at a significantly lower cost than is typical for NASA missions. Our approach meant keeping the mission simple and accepting somewhat higher risks.
Here's one of the sources related to this article: Check here
No comments:
Post a Comment