Australian astronomers published in Nature that the discovery is like finding a needle in a haystack and that this is only possible thanks to the SkyMapper telescope which has unique abilities to find stars whose spectrum indicates that they have a low iron content.
A team led by astronomers at the Australian National University (ANU) discovered the oldest star in the universe to date, which formed shortly after the Big Bang, about 13.7 billion years ago.
The discovery allowed astronomers to study the chemistry of the first stars for the first time and gave scientists a clearer picture of what the universe looked like in its infancy.
"This is the first time we can say without any doubt that we have found the chemical fingerprint of one of the first stars to form in the universe," says Dr Stephen Keller from the ANU School of Astronomy and Astrophysics. "This is one of the first steps in understanding the nature of these stars. What this star has allowed us is to record the fingerprint of these first stars."
The star was discovered by the ANU SkyMapper telescope at Sliding Spring Observatory, which is searching for ancient stars as part of a five-year project to produce the first digital map of the southern sky.
This star is also very close to us, its distance from Earth is about 6,000 light years and it was one of over 60 million stars photographed by SkyMapper in its first year of operation. Prof. Mike Bessel who works with Keller on the research says that the discovery is like finding a needle in a haystack and that this is only possible thanks to the SkyMapper telescope which has unique abilities to find stars whose spectrum indicates that they have a low iron content.
The two confirmed the discovery by viewing the Magellan telescope in Chile.
The newly discovered composition of the star showed that it was formed in the first wave of stars, and that its mass is 60 times that of the Sun. "In order to produce a star like the Sun, basic ingredients such as hydrogen and helium, which were created in the Big Bang, are needed, and a large amount of iron is required, weighing a thousand times the mass of the Earth." said Dr. Keller.
To build such an ancient star, an amount of iron in a rock the diameter of the continent of Australia, and a lot of carbon, is enough. It's a different recipe that tells us a lot about the nature of the first stars and how they died.
Keller says that he thought until recently that the primordial stars died in violent explosions that filled space with iron, but the new star is contaminated with lighter particles such as carbon and magnesium, and even a sign of iron contamination. This fact indicates that the supernova explosions of the first stars had incredibly low energy, which was enough to disintegrate the star, but most of the heavy materials such as iron were consumed by the black hole created at the heart of the explosion," he said.
The researchers estimate that the discovery will resolve the long-standing inconsistencies between the explosions and the predictions of the Big Bang.
The discovery was published this week in the journal Nature.
For the announcement on the Australian National University website
6 תגובות
Just 🙂
A star 12 billion years away will appear to us as it was 12 billion years ago.
A 12 billion year old star close by would look very old, which is probably what is happening here.
A. Ben Ner
It is 6000 years because the universe was created according to 6000 years. Finally someone understood……
At the beginning of the seventh paragraph it is written:
"This star is also very close to us, its distance from Earth is about 6,000 light years."
How? Its distance from us should be about 10-11-12 billion light years.
The title should be "The oldest star formed shortly after the Big Bang discovered"
And not "the oldest star was discovered that..."
Peace,
I am afraid that in writing this article, as well as many other articles in the general literature (mainly in English), an important central mistake was made. The observed star whose name is rather long but has already gained an entry in Wikipedia, is not a star with 60 solar masses! Such a massive star survives only millions of years and there is no chance that it will live from the beginning of the universe to our present day.
What is said in the article is that the observed star has very low levels of iron, indicating that the source of the material in an ancient star with a mass of 60 solar masses, which lived at the beginning of the universe, exploded, and then part of the material in it formed the star we see today (which is a small star, probably Mesad XNUMX of a solar mass or less if he survived that many years).
The article is therefore interesting for two reasons:
1. On the popular level: "Break a record" - find a very very old star. In this context it is important to say that it is very difficult to determine whether a star is 13.7 billion years old, or 12.9. What is known is that the gas from which the star was formed is gas that was created following the death of a first generation star.
2. At the scientific level, at least according to the authors of the article, we are learning something new about the ancient stars - there were ancient stars of the first generation of 60 solar masses and not only of thousands and tens of thousands of solar masses as is generally believed (if the star was formed in a supernova of a star of thousands of masses (Shemesh had a different composition). I don't know if there is really anything new here.
The original article
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12990.html
Wikipedia
http://en.wikipedia.org/wiki/SMSS_J031300.36-670839.3
In the last line - *Observations