Scientists at the European Southern Observatory (ESO) have revealed the most primitive stars outside of the Milky Way. These stars had remained hidden for years, but now they have been detected thanks to new observations by the ESO’s Very Large Telescope.
It is believed that primitive stars were formed 13.7 billion years ago from matter formed right after the Big Bang. According to the ESO, they are stars that are considered “extremely poor metal stars” since they have less than a thousandth of the amount of metallic elements found in the sun. The term “metal” in astronomy refers to all elements heavier than hydrogen and helium.
What enables the scientific community to detect the elements? Each element that composes a star absorbs light of a particular frequency—color. When astronomers analyze star light through a spectrograph, they obtain the “spectrum” of the star. These measurements allow scientists to know what types of elements are within a star and in what quantities.
“Only subtle differences distinguish the chemical fingerprint of a normal metal-poor star from that of an extremely metal-poor star, explaining why previous methods did not succeed in making the identification,” according to an ESO press release.
With thorough computer analysis of the stars’ spectra and the aid of extremely detailed information provided by the new UVES (Ultraviolet-Visual Echelle Spectrograph) on the Very Large Telescope, scientists were able to confirm the existence of these primitive stars, that is, stars that are extremely metal-poor.
“Not only has our work revealed some of the very interesting, first stars in these galaxies, but it also provides a new, powerful technique to uncover more such stars,” said lead researcher Dr. Else Starkenburg. These discoveries mean a significant advancement in the field of star analysis, and they have now taken us one step closer toward understanding the universe and how it came to be.
The only problem that this new type of analysis has is the amount of time it takes. “Just a small number of stars can be observed this way because it is very time consuming,” said researcher Dr. Vanessa Hill in the press release.
The research is published in the journal Astronomy & Astrophysics.
To read the research paper, please visit http://www.aanda.org/index.php?option=article&access=doi&doi=10.1051/0004-6361/200913759&view=pdf
It is believed that primitive stars were formed 13.7 billion years ago from matter formed right after the Big Bang. According to the ESO, they are stars that are considered “extremely poor metal stars” since they have less than a thousandth of the amount of metallic elements found in the sun. The term “metal” in astronomy refers to all elements heavier than hydrogen and helium.
What enables the scientific community to detect the elements? Each element that composes a star absorbs light of a particular frequency—color. When astronomers analyze star light through a spectrograph, they obtain the “spectrum” of the star. These measurements allow scientists to know what types of elements are within a star and in what quantities.
“Only subtle differences distinguish the chemical fingerprint of a normal metal-poor star from that of an extremely metal-poor star, explaining why previous methods did not succeed in making the identification,” according to an ESO press release.
With thorough computer analysis of the stars’ spectra and the aid of extremely detailed information provided by the new UVES (Ultraviolet-Visual Echelle Spectrograph) on the Very Large Telescope, scientists were able to confirm the existence of these primitive stars, that is, stars that are extremely metal-poor.
“Not only has our work revealed some of the very interesting, first stars in these galaxies, but it also provides a new, powerful technique to uncover more such stars,” said lead researcher Dr. Else Starkenburg. These discoveries mean a significant advancement in the field of star analysis, and they have now taken us one step closer toward understanding the universe and how it came to be.
The only problem that this new type of analysis has is the amount of time it takes. “Just a small number of stars can be observed this way because it is very time consuming,” said researcher Dr. Vanessa Hill in the press release.
The research is published in the journal Astronomy & Astrophysics.
To read the research paper, please visit http://www.aanda.org/index.php?option=article&access=doi&doi=10.1051/0004-6361/200913759&view=pdf
