The technique can be used by comparatively small telescopes on the ground, making exoplanet chemistry more widely accessible than ever before. First observations have yielded a fundamentally new result about exoplanet atmospheres. The results have been reported in the February 4, 2010 issue of the journal Nature.
Extraction of an exoplanet spectrum
Chemical studies of exoplanets - planets that orbit not the Sun, but distant stars - rely on spectroscopy, the systematic study of light emitted, reflected or absorbed by those planets at different colors, or wavelengths. Such studies used to be the domain of space observatories and of the world's largest ground-based telescopes (see the MPIA Science Release 2010-01-13). Now, a new data analysis technique successfully pioneered by a group of astronomers from the US, the UK and Germany has brought exoplanet spectroscopy to a much smaller (and more wide-spread) class of ground-based telescopes.
It took the researchers more than two years to develop their method so that it could be applied to spectroscopic observations of the exoplanet HD 189733b made in 2007 with a 3 metre telescope. Using the new method, the identification of specific molecules such as methane and carbon dioxide became possible. The planet, a gas giant similar to Jupiter, orbits the star HD 189733 A in the constellation Vulpecula (or "Fox"), at a distance of 63 light-years from Earth. The spectrum included an interesting wavelength region that is not observable with current space telescopes.
As seen from Earth, the planet HD 189733b periodically moves behind its host star in a planetary eclipse. The planet's spectrum is extracted by comparing the system's light before and after the star hides the planet from sight. Unfortunately, the same atmospheric turbulence which is responsible for the twinkling of stars in the night sky introduces disturbances that are very difficult to account for. Co-author Jeroen Bouwman of the Max Planck Institute for Astronomy explains: "Using newly developed calibration techniques, we can distinguish the variations in time due to the planetary eclipse from those that are due to atmospheric disturbances, or to instrumental artefacts. In this way, we can tell which part of the light is from the exoplanet, and which from the star." Previously, this kind of measurement had only been possible with space telescopes, where observing time is rationed out very strictly. Now, exoplanet spectroscopy becomes accessible to dozens of ground-based telescopes with mirror sizes down to a few metres, and without the need for specialized spectrographic equipment.
The study's lead author, Mark Swain from NASA's Jet Propulsion Laboratory (a former guest scientists of the Max Planck Institute for Astronomy) explains further: "The fact that we have used a relatively small, ground-based telescope is exciting because it implies that the largest telescopes on the ground, using this technique, may be able to characterize terrestrial exoplanet targets." The chemical study of terrestrial, or Earth-like, planets, will be a key step in the search for exoplanets with habitable conditions, or even life on other planets - a crucial, if long-term, aim of modern astronomy. Co-author and MPIA director Thomas Henning adds: "This is exciting news for new instruments such as the LUCIFER spectrograph being installed at the Large Binocular Telescope in Arizona."
The first measurements using the new techniques provide key data to those modelling exoplanet atmospheres. Previous models were simplified in that they admitted only comparatively slow changes in atmospheric conditions. Researchers knew this to be unrealistic, but did not have sufficient data to distinguish between those overly simplified models and more realistic ones. The new spectroscopic data allows for just such differentiation, allowing astronomers to develop new, more realistic models of exoplanet atmospheres.
ContactDr. Jeroen Bouwman (Coauthor)
Dr. Markus Pössel | Max-Planck-Institut
Igniting a solar flare in the corona with lower-atmosphere kindling
29.03.2017 | New Jersey Institute of Technology
NASA spacecraft investigate clues in radiation belts
28.03.2017 | NASA/Goddard Space Flight Center
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences