Scientists discover oldest star in universe

Scientists have identified a star, at least 13.2 billion-years-old, as the oldest yet seen in the universe and it is just 186 light years away from Earth.

The Big Bang is calculated by scientists to have taken place about 13.77 billion years ago and the star, known as HD 140283, was among the earliest stars to form.

"We believe this star is the oldest known in the Universe with a well determined age," Howard Bond, an astronomer at Pennsylvania State University, told the American Astronomical Society.

Since it contains some heavy elements it is thought to have been one of the second generation of stars to be created following the Big Bang.

The first generation of stars contained hardly any elements heavier than helium but when they exploded in a succession of supernovas within a few hundred million years after forming they were replaced by stars like HD 140283.

Observations from the Hubble Telescope helped researchers fix the distance of the star from the Earth with unprecedented accuracy which allowed them to make more accurate measurements of how brightly it shines.

Once its brightness was established they were able to work out how rapidly its hydrogen is being exhausted and so determine its age.

When stars start running short of hydrogen they start dimming which is regarded as a reliable indicator of age.

The actual age that the astronomers' calculations gave was 13.9 billion years but calculations of this type usually contain large error margins, the report said.

In the case of HD 140283 the error margin was 700 million years, making it at least 13.2 billion years old.

One other star, known as Methuselah2, has previously been shown to be 13.2 billion years old but the research team are confident they have determined HD 140283's age with greater certainty.

Scientists make new material

Lead investigator Vijay Sivan from RMIT's Platform Technologies Research Institute says these marbles are like flexible ball bearings that can endure high impacts and temperatures, and operate like semi-conducting systems.

He says it is early days but the possibilities of the new platform appear to be "amazing", as it overcomes the limitations of liquid metals.

"Because it is a liquid metal it can be used in soft electronics where you need flexibility," Dr Sivan told AAP.

"It has a nanoparticle coating so it will not stick on the surface and also by having a functional material as a coating you can use it like a transistor.

"Again, because it's liquid metal, any damage caused in the circuit can be self-healed."

He says he and his colleagues look forward to exploring the potential of liquid metal marbles in a range of applications.

It could be used in optical sensing as a heavy metal sensor and it also has a high sensitivity to gas.

The multidisciplinary team research, published in the journal Advanced Functional Materials, stemmed from investigations into flexible conductive systems for electronic and electromagnetic units.

More than 700 species of bacteria in breast milk identified

Scientists have found more than 700 species of bacteria in breast milk, the main source of nourishment for newborns.

Spanish researchers traced the bacterial microbiota map in breast milk and found a larger microbial diversity than originally thought.

The breast milk received from the mother is one of the factors determining how the bacterial flora will develop in the newborn baby. However, the composition and the biological role of these bacteria in infants remain unknown.

A group of Spanish scientists have now used a technique based on massive DNA sequencing to identify the set of bacteria contained within breast milk called microbiome.

The finding will enable pre- and postnatal variables influencing the micriobial richness of milk to be determined.

Colostrum is the first secretion of the mammary glands after giving birth. In some of the samples taken of this liquid, more than 700 species of these microorganisms were found, which is more than originally expected by experts.

"This is one of the first studies to document such diversity using the pyrosequencing technique (a large scale DNA sequencing determination technique) on colostrum samples on the one hand, and breast milk on the other, the latter being collected after one and six months of breastfeeding," explain the coauthors, Maria Carmen Collado, researcher at the Institute of Agrochemistry and Food Technology (IATA-CSIC) and Alex Mira, researcher at the Higher Public Health Research Centre (CSISP-GVA).

The most common bacterial genera in the colostrum samples were Weissella, Leuconostoc, Staphylococcus, Streptococcus and Lactococcus.

In the fluid developed between the first and sixth month of breastfeeding, bacteria typical of the oral cavity were observed, such as Veillonella, Leptotrichia and Prevotella.

"We are not yet able to determine if these bacteria colonise the mouth of the baby or whether oral bacteria of the breast-fed baby enter the breast milk and thus change its composition," outline the authors in a statement.

The study also found that the milk of overweight mothers or those who put on more weight than recommended during pregnancy contains a lesser diversity of species.

The type of labour also affects the microbiome within the breast milk: that of mothers who underwent a planned caesarean is different and not as rich in microorganisms as that of mothers who had a vaginal birth.

The results also suggested that the hormonal state of the mother at the time of labour also plays a role.

"The lack of signals of physiological stress, as well as hormonal signals specific to labour, could influence the microbial composition and diversity of breast milk," the authors said.

The study was published in the American Journal of Clinical Nutrition.

Proposed telescope will double up as planet searching tool Proposed telescope will double up as planet searching tool

While the Rs 300-crore National Large Solar Telescope (NLST) will study the sun, the facility can also be used at night to look for planets outside the solar system. The NLST is expected to be ready by 2017.

“The telescope will also be used for other activities like searching for extra solar planets,” S S Hasan, former director of the Indian Institute of Astrophysics in Bangalore, which is making the telescope, said at the centenary session of the Indian Science Congress here.

Ever since the discovery of the first exo-planet way back in 1995, close to 800 exo-planets have been identified by scientists, primarily due to the Kepler space mission and its predecessors.

The NLST will mainly study the sun, to know more about its magnetic field, sun spots and solar activity. When completed, it will be one the world’s largest solar telescopes.

The Indian telescope is most likely to be located near Pangong Tso Lake in Lad­akh close to the Sino-Indian border. “The fabrication is expected in 2013. It will take three and a half years to build the telescope and the first light is expected by 2017,” Hasan told.