Signatures of the first stars
A primitive star with extremely low iron content has been discovered by an international research team from Sweden, Japan, Germany, USA, Australia and Great Britain. The results are published in Nature online this week.
In 2001, the giant star HE0107-5240 was discovered among a large number of stars examined as part of the Hamburg/ESO* survey. Detailed studies revealed that the star had by far the lowest iron content ever recorded - 200 000 times lower than the Sun. Previously, only stars with iron contents up to 10 000 times lower than the solar value were known. Recently, a second star was discovered with similar iron content, designated HE1327-2326.
- These two stars are the most chemically primitive stars known, and therefore provide information on the nature of the first objects that formed in the Universe after the Big Bang, Paul Barklem from Uppsala university, Sweden, says.
Notably, HE1327-2326 is not a giant but a dwarf or sub-giant star, meaning that it is comparatively unevolved. The abundance of some chemical elements in evolved giant stars may have been altered by processes occurring during the star’s evolution; however, in an unevolved dwarf or sub-giant star we expect that the chemical composition is close to the original composition of the gas from which the star formed.
Analysis of the spectra for both stars, obtained with the world’s largest telescopes, allows the chemical composition of each star to be determined. The stars’ chemical abundances show similarities, such as large abundances of carbon and nitrogen, which suggest that these two stars may have formed in a similar way. The detailed interpretation of the chemical signatures of these two stars, and similar stars for which we continue to search, should help us to understand exactly how the first generations of stars were formed, and which elements were produced when they ended their lives in supernova explosions.
* ESO = European Southern Observatory
Anneli Waara | alfa
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Mapping the interaction of a single atom with a single photon may inform design of quantum devices
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...