The mean size of the observed Mira stars and their surrounding molecular layer is compared to the size of the inner Solar System. The Earth’s, Mars’ and Jupiter’s orbits are shown, as well as the Sun’s position. The picture illustrates that when the Sun becomes a Mira-type star in about 5 billion years, it will nearly reach Mars’ orbit and its surrounding molecular layer will extend far beyond Mars.
For the first time, an international team of astronomers led by Guy Perrin from the Paris Observatory/LESIA, (Meudon, France) and Stephen Ridgway from the National Optical Astronomy Observatory (Tucson, Arizona, USA) has observed the close environment of five so-called red giant Mira stars, using astronomical interferometric techniques. They found that the observed Mira stars are embedded in a shell of water vapor and possibly of carbon monoxide that extends to twice the stellar radius. Studying these Mira stars is of particular interest since they are now undergoing a late stage of the evolution that one-solar mass stars, including our Sun, experience. Therefore, these stars illustrate the fate of our Sun five billion years from now. Would such a star, including its surrounding shell, be located at the Sun’s position in our solar system, it would extend far beyond Mars.
Although they are really very large (up to a few hundred solar radii), red giant stars are point-like to the unaided human eye on Earth, and even the largest telescopes fail to distinguish their surfaces. This challenge can be overcome by combining signals from separate telescopes using a technique called “astronomical interferometry” that makes it possible to study very small details in the close surroundings of Mira stars. Ultimately, images of the observed stars can be reconstructed.
Mira stars, named after the first such known object, Mira (omicron Ceti), have been observed for more than 400 years by astronomers both professional and amateur. This class of variable red giants is famous for their pulsations that last for 80-1000 days and that cause their apparent brightness to vary by ten or more during a cycle at visible wavelengths. A possible explanation of their significant variability is that large amounts of material, including dust and molecules, are produced during each cycle. This material blocks the stellar radiation until the material becomes diluted by expansion. The close environment of Mira stars is therefore complex, and the characteristics of the central object are difficult to observe.
Jennifer Martin | alfa
NASA spacecraft investigate clues in radiation belts
28.03.2017 | NASA/Goddard Space Flight Center
Researchers create artificial materials atom-by-atom
28.03.2017 | Aalto University
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...
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