The ability to explore remote worlds in space has been enhanced through a polarization technique that allows the first ever detection of light reflected by extrasolar (exoplanet) planets. The study has been accepted for publication in Astrophysical Journal Letters.
An international team of astronomers, led by Professor Svetlana Berdyugina of ETH Zurich's Institute of Astronomy, has for the first time ever been able to de-tect and monitor the visible light that is scattered in the atmosphere of an exoplanet. Employing techniques similar to how Polaroid sunglasses filter away reflected sunlight to reduce glare, the team of scientists were able to extract polarized light to enhance the faint reflected starlight 'glare' from an exoplanet. As a result, the scientists could infer the size of its swollen atmosphere. They also directly traced the orbit of the planet, a feat of visualization not possible using indirect methods.
The transiting exoplanet under study circles the dwarf star HD189733 in the constellation Vulpecula and lies more than 60 light years from the earth. Known as HD189733b, this exoplanet was discovered two years ago via Doppler spec-troscopy. HD189733b is so close to its parent star that its atmosphere expands from the heat. Until now, astronomers have never seen light reflected from an exoplanet, although they have deduced from other observations that HD189733b probably resembles a 'hot Jupiter' - a planet orbiting extremely closely to its parent star. Unlike Jupiter, however, HD189733b orbits its star in a couple of days rather than the 12 years it takes Jupiter to make one orbit of the sun.
Two half-moon phases
The international team, consisting of Svetlana Berdyugina, Dominique Fluri (ETH Zurich), Andrei Berdyugin and Vilppu Piirola (Tuorla Observatory, Finland), used the 60cm KVA telescope by remote control. The telescope, which belongs to the Royal Swedish Academy of Science, is located at La Palma, Spain and was modernised by scientists in Finland. The researchers obtained polarimetric measurements of the star and its planet. They discovered that po-larization peaks near the moments when half of the planet is illuminated by the star as seen from the earth. Such events occur twice during the orbit, similar to half-moon phases.
The polarization indicates that the scattering atmosphere is considerably larger (>30%) than the opaque body of the planet seen during transits and most probably consists of particles smaller than half a micron, for example atoms, molecules, tiny dust grains or perhaps water vapour, which was recently suggested to be present in the atmosphere. Such particles effectively scatter blue light - in exactly the same scattering process that creates the blue sky of the earth's atmosphere. The scientists were also able for the first time to recover the orientation of the planet's orbit and trace its motion in the sky.
"The polarimetric detection of the reflected light from exoplanets opens new and vast opportunities for exploring physical conditions in their atmospheres", Pro-fessor Svetlana Berdyugina said. "In addition, more can be learned about radii and true masses, and thus the densities of non-transiting planets."Bibliography:
Prof. Svetlana Berdyugina | idw
APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie
First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences