Being able to measure things like the mass, temperature and atmospheric composition of exoplanets should generate some interesting new data for analysis, with possible implications for climate theory.
A team of scientists and engineers led by Princeton researchers recently reported the successful operation of a new instrument for the Subaru Telescope in Hawaii that will allow astronomers to make direct observations of planets orbiting nearby stars.
The instrument, dubbed CHARIS, was designed and built by a team led by N. Jeremy Kasdin, a professor of mechanical and aerospace engineering. It allows astronomers to isolate light reflecting from planets larger than Jupiter and then analyze the light to determine details about the planets’ size, age and atmospheric constituents.
The recent observation is known in the astronomical community as a “first light,” a first field test of the instrument on the telescope that demonstrates it is operating successfully. “We couldn’t have been more pleased by the results,” said Kasdin. “CHARIS exceeded all of our expectations. I can’t praise our team enough for their extremely hard work and dedication that made CHARIS a success. It is on track to be available for science observations starting in February 2017.”
“CHARIS is a key addition to the growing exoplanet imaging and characterization capabilities at Subaru Telescope,” said Olivier Guyon, the leader of the adaptive optics program at Subaru and a faculty member at the University of Arizona. “With CHARIS spectra we can now do a lot more than simply detect planets: we can measure their temperatures and atmosphere compositions.”
“By analyzing the spectrum of a planet, we can really understand a lot about the planet,” said researcher Tyler Groff. “You can see specific features that can allow you to understand the mass, the temperature, the age of the planet.”
CHARIS has a relatively narrow field of view. Groff said it observes about 2 arcseconds of the sky. (The full moon seen from Earth is about 1,800 arcseconds.) But it has the ability to take images across a very wide band of wavelengths of light, allowing for detailed analysis of anything in its field.
“We tested CHARIS on Neptune, but the entire planet doesn’t even fit on our detector,” Groff said. However, the spectrograph’s field of view is so detailed that the researchers were able to make interesting observations of clouds floating across the planet’s surface.
Groff said there has been a great deal of interest in the project in the astronomical community and the principal investigators are now reviewing research proposals.
“There is a lot of excitement,” he said. “CHARIS is going to open for science in February to everyone.”
Talkshop note: these are extracts from the full report.