Australian-led astronomers find the most star that is iron-poor the Galaxy, hinting during the nature for the first stars in the Universe.
A newly discovered ancient star containing a record-low level of iron carries evidence of a class of even older stars, long hypothesised but assumed to own vanished.
In a paper published when you look at the journal Monthly Notices for the Royal Astronomical Society: Letters, researchers led by Dr Thomas Nordlander regarding the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) confirm the presence of an ultra-metal-poor red giant star, located in the halo associated with the Milky Way, on the other side of the Galaxy about 35,000 light-years from Earth.
Dr Nordlander, through the Australian National University (ANU) node of ASTRO 3D, together with colleagues from Australia, the US and Europe, located the star with the university’s dedicated SkyMapper Telescope at the Siding Spring s Observatory in NSW.
Spectroscopic analysis indicated that the star had an iron content of only one part per 50 billion.
“That’s like one drop of water in an Olympic pool that is swimming” explains Dr Nordlander.
“This incredibly anaemic star, which likely formed just a few hundred million years after the Big Bang, has iron levels 1.5 million times lower than compared to the sunlight.”
The very stars that are first the Universe are believed to own consisted of only hydrogen and helium, along side traces of lithium. These elements were created in the aftermath that is immediate of Big Bang, while all heavier elements have emerged from the heat and pressure of cataclysmic supernovae – titanic explosions of stars. Stars like the Sun that are high in heavy element therefore contain material from many generations of stars exploding as supernovae.
As none associated with the first stars have yet been found, their properties remain hypothetical. They were long likely to have now been incredibly massive, perhaps hundreds of times more massive as compared to Sun, also to have exploded in incredibly energetic supernovae known as hypernovae.
Dr Nordlander and colleagues suggest that the star was formed after one of several first stars exploded. That exploding star is found to own been rather unimpressive, just ten times more massive than the Sun, also to have exploded only feebly (by astronomical scales) so that the majority of the heavy elements created when you look at the supernova fell back to the neutron that is remnant put aside.
Only a tiny bit of newly forged iron escaped the remnant’s gravitational pull and went on, in concert with far larger levels of lighter elements, to create a brand new star – one of the very first second generation stars, who has now been discovered.
Co-researcher Professor Martin Asplund, a chief investigator of ASTRO 3D at ANU, said it absolutely was unlikely that any true first stars have survived into the current day.
“The good news is like the one we’ve discovered,” he says that we can study the first stars through their children – the stars that came after them.
The study was conducted in collaboration with researchers from Monash University and the University of the latest South Wales in Australia, the Massachusetts Institute of Technology and Joint Institute for Nuclear Astrophysics, both in america, the Max Planck Institute for Astronomy in Germany, Uppsala University in Sweden, link together with University of Padova in Italy.
The ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) is a $ Research Centre that is 40m of funded by the Australian Research Council (ARC) and six collaborating Australian universities – The Australian National University, The University of Sydney, The University of Melbourne, Swinburne University of Technology, The University of Western Australia and Curtin University.
Using a specially-built, 1.3-meter telescope at Siding Spring Observatory near Coonabarabran, the SkyMapper Southern Sky Survey is producing a high-fidelity digital record of the entire sky that is southern Australian astronomers.
SkyMapper’s Southern Sky Survey is led because of the Research School of Astronomy and Astrophysics at the Australian National University, in collaboration with seven Australian universities additionally the Astronomical that is australian Observatory. The purpose of the project is always to create a deep, multi-epoch, multi-colour digital survey for the entire sky that is southern. This may facilitate an extensive array of exciting science, including discovering the oldest stars in the Galaxy, finding dwarf that is new in orbit round the Milky Way, and measuring the results of Dark Energy on the Universe through nearby supernovae.