Mysteries: If the cosmos is 13.8 billion year old, how can a star be much more than 14 billion years old?


This Digitized sky Survey picture shows the earliest star v a well-determined period in our galaxy. Called the Methuselah star, HD 140283 is 190.1 light-years away. Astronomers sleek the star"s period to about 14.3 billion year (which is older 보다 the universe), plus or minus 800 million years. Photo released march 7, 2013. (Image credit: Digitized sky Survey (DSS), STScI/AURA, Palomar/Caltech, and also UKSTU/AAO)
For an ext than 100 years, astronomers have actually been observing a curious star situated some 190 light years far from planet in the constellation Libra. It rapidly journeys throughout the skies at 800,000 mph (1.3 million kilometers every hour). But much more interesting 보다 that, HD 140283 — or Methuselah together it"s commonly known — is also one the the universe"s oldest well-known stars.

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In 2000, researchers sought to date the star using monitorings via the European Agency"s (ESA) Hipparcos satellite, which estimated period of 16 billion year old. Such a figure was rather mind-blowing and likewise pretty baffling. Together astronomer Howard shortcut of Pennsylvania State college pointed out, the period of the universe — determined from monitorings of the cosmic microwave elevator — is 13.8 billion year old. "It was a severe discrepancy," he said.

Related: The Methuselah Star: Oldest well-known Star Revealed (Gallery)

Taken at confront value, the star"s predicted period raised a significant problem. How could a star be older 보다 the universe? Or, vice versa, how might the cosmos be younger? that was absolutely clear that Methuselah — called in referral to a biblical patriarch that is said to have died aged 969, making the the longest live of every the numbers in the holy bible — was old, due to the fact that the metal-poor subgiant is predominantly made the hydrogen and helium and also contains very little iron. It"s composition meant the star must have come right into being prior to iron came to be commonplace.

But more than 2 billion year older 보다 its environment? Surely the is just not possible.

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Taking a closer look in ~ the age of Methuselah

Bond and also his colleagues set themselves come the job of figuring the end whether or not that initial number of 16 billion was accurate. They pored end 11 set of monitorings that had been recorded between 2003 and 2011 through the well Guidance Sensors that the Hubble Telescope, which do a note of the positions, distances and also energy calculation of stars. In acquiring parallax, spectroscopy and photometry measurements, a better sense the age could be determined.

"One that the uncertainties through the period of HD 140283 was the an accurate distance the the star," link told All around "It was crucial to acquire this right due to the fact that we can better determine its luminosity, and from the its period — the brighter the intrinsic luminosity, the younger the star. We were looking for the parallax effect, which supposed we were viewing the star six months apart come look for the shift in that position due to the orbital movement of the Earth, i m sorry tells united state the distance."

There were additionally uncertainties in the theoretical modelling the the stars, such as the exact rates of nuclear reactions in the core and also the prestige of elements diffusing downwards in the external layers, he said. They worked on the idea that leftover helium diffuses deeper right into the core, leaving much less hydrogen to burn via atom fusion. V fuel used faster, the age is lowered.

This is a backyard watch of the sky neighboring the old Methuselah star, cataloged together HD 140283. Image released in march 7, 2013. (Image credit: A. Fujii and also Z. Levay (STScI))

"Another variable that was important was, of every things, the amount of oxygen in the star," link said. HD 140283 had actually a higher than guess oxygen-to-iron ratio and, due to the fact that oxygen was not abundant in the cosmos for a few million years, the pointed again come a lower age for the star.

Bond and his partners estimated HD 140283"s age to it is in 14.46 billion years — a far-ranging reduction top top the 16 billion formerly claimed. The was, however, still more than the age of the world itself, but the researchers posed a residual uncertainty of 800 million years, i m sorry Bond stated made the star"s age compatible through the period of the universe, also though the wasn"t entirely perfect.

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"Like all measured estimates, that is subject to both random and systematic error," said physicist Robert Matthews that Aston college in Birmingham, UK, who was not affiliated in the study. "The overlap in the error bars offers some indication of the probability the a clash through cosmological age determinations," Matthews said. "In various other words, the finest supported period of the star is in conflict with the for the derived age of the universe , and the dispute can just be addressed by pushing the error bars to their excessive limits."

Further refinements witnessed the age of HD 140283 loss a bit more. A 2014 follow-up examine updated the star"s period to 14.27 exchange rate years. "The conclusion got to was the the age is about 14 billion years and, again, if one has all sources of hesitation — both in the observational measurements and also the theoretical modelling — the error is about 700 or 800 million years, so there is no conflict since 13.8 billion years lies in ~ the star"s error bar," bond said.

This graphic shows a timeline the the universe based upon the huge Bang theory and also inflation models. (Image credit: NASA/WMAP)

Taking a closer look in ~ the period of the universe

For Bond, the similarities in between the period of the universe and also that the this old adjacent star — both that which have actually been identified by different methods of evaluation — is "an remarkable scientific accomplishment which offers very strong evidence for the huge Bang picture of the universe". He said the trouble with the age of the earliest stars is much less major than it remained in the 1990s as soon as the stellar ages were pull close 18 billion year or, in one case, 20 exchange rate years. "With the uncertainties of the determinations, the ages are currently agreeing," shortcut said.

Yet Matthews to trust the problem has not yet been resolved. Astronomers at an global conference of height cosmologists at the Kavli Institute because that Theoretical Physics in Santa Barbara, California, in July 2019 were puzzling over research studies that suggested different periods for the universe. They were looking at measurements of galaxies the are reasonably nearby which suggest the universe is younger by hundreds of millions of years compared to the age established by the cosmic microwave background.

Related: 7 surprising Things about the Universe

In fact, far from gift 13.8 billion year old, as approximated by the europe Planck room telescope"s detailed measurements that cosmic radiation in 2013, the universe might be as young as 11.4 exchange rate years. Among those behind the researches is Nobel laureate Adam Riess of the Telescope scientific research Institute in Baltimore, Maryland.

The conclusions are based on the idea the an widening universe, as displayed in 1929 by Edwin Hubble. This is basic to the huge Bang — the knowledge that over there was when a state of hot denseness the exploded out, stretching It suggests a beginning point that must be measurable, however fresh result are arguing that the growth rate is actually approximately 10% higher than the one suggested by Planck.

Indeed, the Planck team established that the expansion rate to be 67.4 kilometres per second per megaparsec, but much more recent dimensions taken that the expansion rate the the universe point to worths of 73 or 74. That way there is a difference between the measure of how quick the cosmos is expanding today and also the guess of how fast it should be expanding based upon the physics that the early on universe, Riess said. It"s bring about a reassessment of accepted theories while also showing there is still much to learn around dark matter and dark energy, which room thought to it is in behind this conundrum.

Related: Big Bang Theory: 5 weird Facts about Seeing the Universe"s Birth

A greater value for the Hubble consistent indicates a shorter age because that the universe. A continuous of 67.74 km per 2nd per megaparsec would certainly lead to an er of 13.8 billion years, whereas among 73, or also as high together 77 as some studies have shown, would suggest a universe period no better than 12.7 billion years. It"s a mismatch the suggests, when again, the HD 140283 is older 보다 the universe. It has likewise since to be superseded by a 2019 study published in the journal science that suggest a Hubble continuous of 82.4 — arguing that the universe"s age is only 11.4 exchange rate years.

Matthews trust the answers lie in greater cosmological refinement. "I doubt that the observational cosmologists have actually missed something that creates this paradox, fairly than the mainly astrophysicists," that said, pointing come the measurements of the stars gift perhaps an ext accurate. "That"s not because the cosmologists are in any method sloppier, but due to the fact that age determination of the cosmos is topic to more and maybe trickier observational and also theoretical uncertainties than the of stars."

A visualization of the formation of the very first stars. (Image credit: Wise, Abel, Kaehler (KIPAC/SLAC))

So, just how will scientists number this out?

But what might be making the cosmos potentially show up younger than this certain star?

"There are two options, and also the background of science argues that in such situations the fact is a mix the both," Matthews said. "In this case that would certainly be sources of observational error that haven"t been fully understood, plus part gaps in the concept of the dynamics the the universe, such as the stamin of dark energy, which has been the element driver the the cosmic growth for countless billions of year now."

Related: Dark Matter and Dark Energy: The an enig Explained (Infographic)

He argues the opportunity that the present "age paradox" shows time sport in dark energy, and thus a readjust in the price of acceleration — a opportunity theorists have actually found might be compatible through ideas about the basic nature that gravity, such together so-called causal set theory. New research into gravitational tide could assist to resolve the paradox, Matthews said.

To perform this, researchers would look in ~ the ripples in the fabric of and time created by pairs of dead stars, quite than relying on the cosmic microwave background or the surveillance of surrounding objects such as Cepheid variables and supernovae to measure the Hubble continuous — the former resulting in the speed of 67 kilometres per 2nd per megaparsec and the last in 73.

Trouble is, measure up gravitational tide is no basic task, given they to be only straight detected for the first time in 2015. Yet according to Stephen Feeney, an astrophysicist in ~ the Flatiron academy in brand-new York, a breakthrough could be made end the course of the following decade. The idea is to collection data from collisions in between pairs of neutron stars utilizing the visible light these events emit to number out the speed they are moving relative to Earth. It also entails examining the resulting gravitational waves because that an idea of street — both of i m sorry can combine to give a measure up of the Hubble continuous that should be the many accurate yet.

The mystery of the period of HD 140283 is leading to something bigger and more scientifically complex, transforming the understanding of exactly how the universe works.

"The most likely explanations because that the paradox some overlooked observational result and/or something big missing indigenous our knowledge of the dynamics of the cosmic expansion," Matthews said. Exactly what the "something" is, is certain to store astronomers challenged for part time.

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