An international team of astronomers, led by Hervé Bouy from the Max Planck Institute, Garching, Germany and the Observatoire de Grenoble, France, have for the first time measured the mass of an ultra-cool brown dwarf star. The team performed the measurements using four of the most powerful telescopes available. This is the first-ever mass measurement of an L-type star belonging to the new stellar class of very low-mass stars, discovered a few years ago. With a mass of 6.6% of the solar mass, this celestial object is a "failed" star, lying between stars and planets in the evolutionary scheme.
Making use of four of the most famous telescopes worldwide, an international team of astronomers made the first-ever direct measurement of the mass of a so-called L-type star. The star, named 2MASSW J0746425+2000321, is a binary star that was observed for four years with the ESO Very Large Telescope (Chile), the Keck and Gemini Telescopes (Hawaii), and the Hubble Space Telescope.
Precise observations of each component of the binary system were required to be able to compute their masses. As both stars are very close to each other, telescopes providing high-resolution images were needed. Additionally, observations had to be performed over a long period of time (four years) to follow the motion of both stars around each other. Very accurate measurements of the relative position of the individual components were made, so that the full orbit of the binary system could be reconstructed, as illustrated in the following picture. Once the orbit was known, the astronomers were able to compute the total mass of the system using Keplers laws. In addition, very precise measurements of the brightness of each star were needed to be able to compute the individual mass of each component of the system. The astronomers calculated the mass ratio of the system from these brightness measurements, using the theoretical models by G. Chabrier and collaborators (Centre de Recherche Astronomique de Lyon, France). Finally, the mass of each component could be determined.
Jennifer Martin | alfa
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The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
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