Now, a team led by Jacob Bean (Harvard-Smithsonian Center for Astrophysics) has made the first measurements of GJ 1214b's atmosphere. However, the measurements raise as many questions about the planet's atmospheric composition as they answer.
"This is the first super-Earth known to have an atmosphere," said Bean. "But even with these new measurements we can't say yet what that atmosphere is made of. This world is being very shy and veiling its true nature from us."
A super-Earth is a planet up to three times the size of Earth and weighing one to ten times as much. (GJ 1214b is 2.7 times the size of Earth and 6.5 times as massive.) They are likely to be mostly solid (some combination of rock or ices), unlike the hundreds of Jupiter-sized gas giants found to date around distant stars.
Researchers suggested three atmospheric possibilities for GJ 1214b. The most intriguing was a thick blanket of steam vaporized by the nearby star. (This option led to the nickname "waterworld," although it's too hot for an ocean.) The second option was a mini-Neptune with a rocky core surrounded by ices and a hydrogen/helium atmosphere. The third model has no equivalent in our solar system - a big, rocky world with a soupy mix of gases (mainly hydrogen) recently emitted by volcanoes.
To study the planet's atmosphere, the team observed it when it crossed in front of its star. During such transits, the star's light filters through the atmosphere. Gases absorb the starlight at particular wavelengths, or colors, leaving behind a chemical fingerprint detectable from Earth. Similar observations have found gases like hydrogen and sodium vapor in the atmospheres of distant "hot Jupiters."
"This is the first super-Earth to have its atmosphere analyzed. We've reached a real milestone on the road toward characterizing these worlds," stated Bean.
Commenting on the work, Harvard astronomer David Charbonneau, who is not involved in the recent study but led the team that discovered GJ 1214b, agreed. "In less than 10 years, we've gone from studying the atmospheres of alien worlds like Jupiter, to Neptunes, to super-Earths. Earth-sized worlds are next, although they'll be the most difficult."
The spectrum of GJ 1214b proved to be featureless, which ruled out a cloud-free atmosphere composed primarily of hydrogen. If the atmosphere of GJ 1214b has abundant hydrogen, then it must be cloaked by a thick blanket of clouds (like Venus) or haze (like Saturn's moon Titan). A dense, steamy atmosphere also fits the data.
"It would have to be very dense - about one-fifth water vapor by volume," explained Bean. "Compared to our Earth, with an atmosphere that's four-fifths nitrogen and one-fifth oxygen with only a touch of water vapor."
The team examined GJ 1214b in the near-infrared region of the spectrum (780 - 1000 nanometers) using the ground-based Very Large Telescope at Paranal Observatory in Chile. Additional observations in the mid- or far-infrared might finally answer the question: Is the atmosphere of GJ 1214b steamy or gassy?
"A lot of people are putting this planet under a microscope," said Bean. "In the next year, we should have some solid answers about what it's truly like."
Christine Pulliam | EurekAlert!
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy