The young giant gas planet HR 8799c is about 7 times the mass of Jupiter and orbits its star every 200 years.
Researchers have found strong evidence for water on a young gas giant outside our solar system.
The planet known as HR 8799c has a mass of about 7 Jupiter masses and orbits its host star every 200 years. Its atmospheric composition shows that water is likely to be a major component of the planet. However, it lacks methane. The findings come from a new analysis of observations made by state-of-the art instruments on W. M. Keck Observatory on Maunakea, Hawaii.
Planet HR 8799c has been observed repeatedly, but the presence of water in its atmosphere has never been detected before. By combining the new data with a technique called adaptive optics researchers removed the blurring effect of the planet and created the most detailed study yet of its atmosphere. The technique has implications for the search of life beyond Earth.
“This type of technology is exactly what we want to use in the future to look for signs of life on an Earth-like planet. We aren’t there yet but we are marching ahead.” Dimitri Mawet, a professor of astronomy at Caltech and a research scientist at NASA JPL said in a statement.
Located about 129 light years from Earth HR 8799c and three of its companions were the only multiple-planet system to be confirmed using the direct imaging technique. Taking direct images of planets that orbit other stars is a daunting task because the light from the host stars outshines the planets and make them difficult to see.
Once an image is obtained, astronomers can use instruments, called spectrometers to break apart the planet’s light and measure the chemical fingerprints of the atmosphere. So far, this strategy has been used to gain insights into the atmospheres of several giant exoplanets that was previously not possible.
The ultimate goal is to look for chemicals in the atmospheres of Earth-like planets that orbit in the star’s “habitable zone” – the distance within which their surface temperatures permit liquid water. Earth-like exoplanets are currently our best candidates for hosting life.
Ji Wang lead author of the study says. “Right now, with Keck, we can already learn about the physics and dynamics of these giant exotic planets, which are nothing like our own solar system planets.”