While hunting for molecules in a planet’s atmosphere might not be the first thing you’d consider doing when trying to detect a massive celestial object, this is exactly what researchers from the University of Geneva (UNIGE) in Switzerland are doing — and it totally works, reports Science Daily.
In fact, their new method is a lot more efficient at spotting new planets in the sky because it obscures the parent stars, which typically glare so brightly that it’s nearly impossible to see anything around them.
The novel technique changes the game plan and focuses on the atmospheric composition of a potential new planet by searching for specific molecules that are lacking from the host star.
Led by Jens Hoeijmakers, a researcher at the Astronomy Department of UNIGE’s Observatory and a member of NCCR PlanetS, the team created a device that analyzes the molecular spectrum of a planet candidate, detecting the presence of certain types of molecules that are only contained by the planet and not its parent star.
Here’s How It Works
With the help of this innovative technique, the astronomers scope out the sky searching for the atmospheric blueprint of the desired elements. As a result, any planets that might be lurking in the field of vision become discernible and can be easily distinguished.
At the same time, the device turns off the light of the host stars, so to speak, because it only searches for elements that can’t be spotted in the exoplanets’ parent stars.
Hoeijmakers explains what makes his new device so successful.
“By focusing on molecules present only on the studied exoplanet that are absent from its host star, our technique would effectively ‘erase’ the star, leaving only the exoplanet.”
His team tested the new technology on a star called Beta Pictoris, which is orbited by a mysterious gas giant known as Beta Pictoris b — a super-Jupiter weighing about 13 Jupiter masses and roughly 3,000 times more massive than our planet.
As the Inquisitr previously reported, Beta Pictoris b and its host planet are located some 60 light-years away from Earth in the Pictor constellation of the Milky Way.
The astronomers combed through the archives of the European Southern Observatory’s SINFONI instrument and analyzed each pixel in the existing images of Beta Pictoris b.
As Science Daily explains, each pixel in these images contains a specific light spectrum, which the team compared with the spectrum of certain molecules to see if they could detect a correlation that would signal the presence of that element in the exoplanet’s atmosphere.
When the researchers looked for traces of water (H2O) and carbon monoxide (CO), which exist in the atmosphere of Beta Pictoris b, it made the exoplanet become visible and allowed the team to observe it directly without the interference of light coming from its star.
Conversely, when the device began searching for methane (CH4) and ammonia (NH3), which are not present in the exoplanet’s atmospheric composition, Beta Pictoris b vanished from the field of vision since there was nothing to detect by the new technology.
To prove that their invention truly works, the researchers searched for the same four elements in Beta Pictoris and the star remained invisible on their screens, as it doesn’t contain any of these elements.
“This technique is only in its infancy,” says Hoeijmakers, who is convinced this innovation “should change the way planets and their atmospheres are characterized.”
One great thing about the new method of hunting for exoplanets is that it can provide data on their surface temperature as well as that of their host stars. For instance, none of the four molecules could be detected in Beta Pictoris because the star is too hot to support their existence.
Beta Pictoris is nearly 1.8 times more massive than our sun, and it showers its planet with radiation that cooks Beta Pictoris b and leads to extremely high surface temperatures of 1,724 degrees Kelvin (1,451 degrees Celsius, 2,644 degrees Fahrenheit).
This explains why the team didn’t detect methane and ammonia in the planet’s atmosphere since its temperature is too hot for these elements to exist.
“This is why this technique allows us not only to detect elements on the surface of the planet, but also to sense the temperature which reigns there,” notes Hoeijmakers.
His team described the new technique in a study published last week in the journal Astronomy & Astrophysics and available on the arXiv server.
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