Jakarta –
Determining the age of the universe remains one of the biggest questions in modern cosmology. Until now, scientists have estimated the age of the universe by how fast it is expanding.
Reporting from Phys.org, the latest research offers a different approach. Instead of looking at the expansion rate, researchers tried to estimate the age of the universe by studying the ages of the oldest stars in the Milky Way galaxy.
Oldest Stars Used to Calculate the Age of the Universe
Researchers from the University of Bologna and the Leibniz Institute for Astrophysics Potsdam (AIP) propose a new approach to understanding the age of the universe. They used high-precision data from very old stars in the Milky Way galaxy.
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For decades, astronomers have relied on the Hubble constant to calculate the age of the universe. This constant describes how fast the cosmos is expanding.
But a big problem arises, the two main methods produce different measurement numbers. Measurements using relatively close astronomical objects such as Cepheid stars and supernovae give higher values of the Hubble constant, which means the age of the universe is younger.
In contrast, measurements based on cosmic microwave background radiation (cosmic microwave background) indicates the age of the universe is older. This difference became known as the Hubble tension, one of the greatest puzzles in modern cosmology.
This research tries to look at this problem from another point of view. They examined the ages of the oldest stars in the Milky Way to estimate the minimum limit for the age of the universe. The logic is simple, the universe cannot be younger than the oldest stars in it.
In other words, if the age of the oldest stars could be measured accurately, scientists could determine a minimum limit for the age of the universe. Researchers then analyzed a catalog of the ages of more than 200,000 stars in the Milky Way, calculated from data on their brightness, position and distance.
How Old is the Universe?
To obtain more precise results, the research team used data from the European Space Agency’s (ESA) Gaia space mission, which provides very accurate measurements of star distances and spectra.
“Using highly precise stellar data, we determined the ages of carefully selected very old stars in the Milky Way,” the researchers wrote in the report.
From this large data set, the researchers selected about 100 of the oldest stars with the most reliable age estimates. The results of the analysis show the most likely age of these stars to be around 13.6 billion years.
This finding sheds new light on the debate over the age of the universe. The figure is more consistent with estimates of the age of the cosmos from observations of the cosmic microwave background radiation, compared with other methods that produce younger ages.
The study’s lead author, Elena Tomasetti from the University of Bologna, explained the importance of a cross-disciplinary approach in this research.
“This project shows how combining expertise from different fields can open new windows for answering fundamental questions. Measuring the age of stars is a complex challenge, but we now live in an era when the quantity and quality of data allows us to achieve unprecedented precision,” he said.
However, the researchers emphasized that these results are not yet the final answer. With the release of the next Gaia data in the future, scientists hope to be able to estimate the ages of stars more accurately and further narrow down estimates of the age of the universe.
(rhr/pal)
