An international team of astronomers using the worlds biggest telescopes have directly measured the mass of an ultra-cool brown dwarf star and its companion dwarf star for the first time. Barely the size of the planet Jupiter, the dwarf star weighs in at just 8.5 percent of the mass of our Sun. This is the first ever mass measurement of a dwarf star belonging to a new stellar class of very low mass ultra-cool dwarf stars. The observation is a major step towards our understanding of the types of objects that occupy the gap between the lightest stars and the heaviest planets.
This image shows the orbit of the brown dwarf around the ultra-cool L-dwarf. Each red dot on the orbit (in blue) corresponds to one observation made with a ground- or space-based telescope. The observations cover 60% of the whole orbit. Credit: ESA/NASA and Herve Bouy (Max-Planck-Institut für Extraterrestrische Physik/ESO, Germany)
Image credit: ESA/NASA and Herve Bouy (Max-Planck-Institut für Extraterrestrische Physik/ESO, Germany)
In 2000 the NASA/ESA Hubble Space Telescope detected a brown dwarf companion around the star named 2MASSW J0746425+2000321. In the subsequent four years the system was tracked by the NASA/ESA Hubble Space Telescope, the European Southern Observatory’s Very Large Telescope (Chile), the Gemini North (Hawaii) and the Keck Telescopes (Hawaii). The masses of the stars could be measured from the orbital motions of the two objects. With a mass of 8.5% of our Suns mass, the primary star is precariously close to the theoretical minimal fusion limit, which is 7.5 percent of our Suns mass. Objects below this limit are called brown dwarfs, failed stars or even super-planets, as their properties are more similar to those of large Jupiter-type planets than stars. The brown dwarf is measured to be 6.6 percent of the Suns mass, and thereby too puny to shine by nuclear fusion.
The mass measurements were made by an international team of astronomers led by Hervé Bouy from the Max-Planck-Institut für Extraterrestrische Physik/ESO, Germany and the Observatoire de Grenoble, France; Eduardo Martin (Instituto de Astrofisica de Canarias, Spain); and Wolfgang Brandner (Max Planck Institut für Astronomie, Germany).
Lars Christensen | ESA
NUS engineers develop novel method for resolving spin texture of topological surface states using transport measurements
26.04.2018 | National University of Singapore
European particle-accelerator community publishes the first industry compendium
26.04.2018 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
26.04.2018 | Power and Electrical Engineering
26.04.2018 | Life Sciences
26.04.2018 | Power and Electrical Engineering