Meteorite analysis shows that our solar system consists of twice as much supernova dust than previously thought.
For scientists, meteorites are valuable witnesses of our early Solar System. They consist of the oldest building blocks of our planetary system but also contain inclusions of tiny stardust grains, which are older than our sun.
The most common type of stardust consists of silicate grains, which are only a few hundred nanometers in size. For the most part, the stardust in meteorites derives from the remains of red giant stars. A smaller yet significant percentage of stardust stems from supernova explosions.
Scientists from the Max Planck Institute for Chemistry have now discovered that the amount of silicate stardust originating from supernovae is twice as high as previously assumed.
They estimate the fraction to be between 25 and 30 percent. From this, they have determined that the dust and gas cloud from which our Solar System originated 4.6 billion years ago, contained about one percent of “real” supernova dust.
“Our study shows that a significant proportion of presolar stardust grains found in meteorites, which had been thought to originate from red giant stars, actually stems from supernova explosions,” says physicist Jan Leitner.
The Mainz-based scientists successfully proved this through the precise measurement of the oxygen and magnesium isotope ratios in silicate stardust grains. It emerged that the magnesium isotopic compositions in some of the examined silicate stardust grains can be explained by nova models, but not their oxygen isotope ratios. Although the latter can be explained by red giant star models, this is not the case for the magnesium isotopic compositions.
The measured isotopic compositions of both magnesium and oxygen can, however, be explained by more recent supernova models.
Researchers explain this phenomenon by the fact that the nuclear fusion processes that occur with supernovae, novae and red giants, take place under different conditions. This results in a large number of elements having distinctive isotopic signatures, which leave behind specific “fingerprints” within the silicate grains.
The original assumption that the vast proportion of stardust stems from red giants is based on analyses of oxygen isotope ratios in silicate grains, which differ in very distinctive ways from those of our sun.
The examined stardust grains were discovered in a variety of meteorites found in the Antarctic and the Sahara. In a previous study, Max Planck research scientists had identified the stardust grains by their anomalous oxygen isotopic compositions to determine the abundances of stardust in these meteorites.
The Max Planck research scientists were able to verify this with the help of a special mass spectrometer, the so-called NanoSIMS. This instrument is able to determine the isotopic composition of materials on a size scale of 50-100 nanometers. The precise measurement of the magnesium isotopes only became possible one and a half years ago through the acquisition of a new type of ion source. Before this the ion beam available for magnesium isotope measurements was wider than the grains of interest, precluding accurate analyses because of isotopic dilution with the surrounding material.
A supernova, according to astronomers, is the brief, bright flash of a star, significantly heavier than our sun, caused by an explosion at the end of its life cycle. The original star is destroyed in this process, and the majority of its matter released into interstellar space, leaving a neutron star or a black hole behind.
A red giant is a “dying” star, whose mass is comparable to our sun and that ends as a so-called white dwarf, i.e., a small, very compact star, after ejecting most of its material into interstellar space. Our sun will also become a red giant star in a few billion years, which will alter the oxygen isotopic composition on its surface.
In a nova explosion, hydrogen-rich material is transferred from a companion star to the surface of a white dwarf, triggering a thermonuclear explosion.
Dr. Jan Leitner
Max Planck Institute for Chemistry
A New Population of Dust from Stellar Explosions among Meteoritic Stardust
Jan Leitner and Peter Hoppe
Nature Astronomy, June 2019
Dr. Susanne Benner | Max-Planck-Institut für Chemie
Appreciating the classical elegance of time crystals
20.09.2019 | ETH Zurich Department of Physics
'Nanochains' could increase battery capacity, cut charging time
20.09.2019 | Purdue University
How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery's negative electrode material. If the battery runs out of these ions, it can't generate an electrical current to run a device and ultimately fails.
Materials with a higher lithium ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in...
To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...
Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.
The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.
At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.
Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...
Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....
19.09.2019 | Event News
10.09.2019 | Event News
04.09.2019 | Event News
20.09.2019 | Life Sciences
20.09.2019 | Life Sciences
20.09.2019 | Life Sciences