According to the most complete at the moment the investigation of the age of the night sky, a large part of the stars that ever will exist, have already appeared. About it says Iain Steadman in Wired Magazine (USA).

An international team of astronomers has used three telescopes - infrared telescope, the United Kingdom (UK Infrared Telescope) and telescope "Subaru" (Subaru Telescope), located in Hawaii and Chile's Very large telescope (Very Large Telescope) - to examine trends in the formation of stars from the earliest days of the universe. The extrapolation of the obtained data suggest that half of all the stars that have ever existed, 9-11 occurred billions of years ago, and only half arose later. This means that the rate of emergence of new stars fell sharply. If this trend continues and now, it means that 95% of stars that ever will exist in the Universe, had begun.

Several earlier studies were devoted to specific "epochs", but the difference methods used by researchers, has limited the possibilities to compare the obtained results to develop a more complete model of how evolved stars during the existence of the universe.

It has long been known that many stars, including our own, probably arose from the dust left over from other stars that were larger and turned into a supernova at the dawn of the universe. The problem was to calculate how many stars the universe was created earlier and how much generates now, since there is such an impression that at some point the stars started to form much less.

Telescopes were looking for alpha particles emitted by hydrogen atoms (a sign of star formation, manifested bright red), large areas of the sky. The shots were made of view of the universe at certain moments of time when she was two, four, six and nine million years, the material is ten times greater than in previous similar studies.

The results clearly showed that half ever existed in the universe of stars appeared more than nine billion years ago, and the remaining half was formed for a further period. The study's lead author David Sobral (David Sobral) from Leiden University writes on the website of the telescope "Subaru": "star Formation in the Universe as a whole is steadily declining in the last 11 billion years. Now it is 30 times less than during the likely peak of 11 billion years ago. If this trend continues, the Universe will be added in the future, only 5% of the stars. We live in a Universe dominated by old stars. The main action in the Universe happened billions of years ago!"

It is important that this allows to explain previously finally was drop confusing the difference between the number of stars that we can see and the number of the stars, as we believe, should be created universe. The first generation of stars probably was very big by the size is hundreds of times greater than our Sun - and must quickly burn their fuel, to turn into a supernova and die, causing scattered disks of dust, which later formed the stars and planetary systems.

The results of the study confirmed this, showing that nine billion years ago, after the first generation of stars, star formation slowed sharply. After that new birth the same number of stars in the second half of the observed star formation - it took five times more time. Data from other studies that used a smaller sampling or other techniques, also correspond developed by scientists schedule and confirm the theory of "early peak and a rapid decline". A new study published in the Monthly Notices of the Royal Astronomical Society.

Thus, unfortunately, our universe seems to be exhaled. The study predicts that in a few billion years, you will see the birth of the last star - unless, of course, mankind will live that long.