JWST observations of the ultra hot super Earth exoplanet TOI-561 provide the evidence to date for atmosphere surrounding rocky planet beyond our solar system.
A team of astronomer led by Carnegie researchers has uncovered the clearest evidence so far a rocky planet outside our Solar System possesses an atmosphere.
The findings reported in The Astrophysical Journal Letters are based on observations from NASA James Webb Space Telescope JWST.
The data indicates the presence of atmosphere on unlikely world an ancient extreme hot super Earth that is thought to be covered by global ocean of molten rock.
Galaxy
The planet called TOI-561 b is twice as massive as Earth but is otherwise very different from our planet.
Its extreme conditions are driven by its tight orbit around its star.
The star itself is smaller and cooler than the Sun, TOI-561 b circles it one fortieth the distance between Sun and Mercury.
This close orbit the planet completed a full year in only 10.56 hours and one hemisphere is exposed to starlight.
Astronomers would have predicted that planet like this is too small and hot to retain its own atmosphere for long after formation explained Carnegie Science Postdoctoral Fellow Nicole Wallack the paper second author.
Our observations suggest it is surrounded by relative thick blanket of gas spending conventional wisdom about ultra short period planets.
Nasa images
JWST observations
These are first results from JWST General Observers Program 3860 which involved observing the system continuously for over 37 hours while TOI-561 b completed almost for full orbits of the star.
The team is analyzing the full data set to map the temperature all the method around the planet and narrow down the composition of atmosphere.
Teske and Wallack leadership on this JWST paper present a tradition of Carnegie Science excellence dating back to mission conception three decades before and extending through first four cycles of time allocation on revolutionary space telescope.
JWST finished calibrations and start collecting data for astronomical research programs, Teske, Wallack and other Carnegie Earth and Planets Laboratory and Observatories affiliated scientists have led over dozen JWST teams and announced groundbreaking results about exoplanet atmospheres galaxy formation.
Appolo
These JWST powered breakthroughs tap directly into our long standing strength in how exoplanet characters are shaped by planetary evolution and dynamics.
There are more results on horizon and we are poised for new wave of Carnegie led JWST science in year ahead.
Challenging Planetary Expectations
In our own solar system planets that are small and intense heated were unable to keep the original gaseous envelops they acquired in their histories.
TOI-561 b appears to have held on its atmosphere even though it orbits a star that is older than the sun.
This lingering atmosphere may account for other puzzle the planets surprisingly low density.
TOI-561 b is lighter than scientist would expect based on size alone and presence of atmosphere could help explain why.
It is not what we call a super puff or cotton candy planet but it is less dense than you would expect if it had earth like composition.
In designing the observing program the team considered that planet low density could be explained by relative small iron core and mantle made of rock is less dense than rocks that comprise Earth interior.
Teske points that this could make sense TOI-561 b is distinct among ultra short period planets in that it orbits a old twice as old as Sun iron poor star in a region of Milky Way famous as thick disk.
It must have shaped in different chemical environment from planets in our own Solar System.
This mean that composition could be representative of planets that formed when universe was relatively young.
Searching for Atmosphere
In deciding to study TOI-561 b the research team suspect that it might be surrounded by thick atmosphere that makes it look larger and thus less dense.
To test existence of TOI-561 b atmosphere the astronomer used JWSY Near Infrared Spectrograph NIRSpec instrument to measure the planet dayside temperature based on brightness in near infrared.
The technique which consist of measuring the decrease in brightness of star planet system as the planet moves behind the star is similar to search for atmospheres in the TRAPPIST-1 system and other rocky worlds.
