Is the Methuselah Star Older Than the Universe?
By: Zeba Academy
Tags: Space Debris, NASA, The Sun, Stars, Solar System

From the birth of the mankind, humans have contemplated about our Universe and the significance that it held, but we have never thought of anything that could be comparatively older than the Universe itself. After all, how is that even possible? Though, over the past centuries, a very fascinating discovery was made that said otherwise. According to the scientists, the Methuselah star was considered to older than the universe. You may be filled with amazement as to how exactly this star could be older than the entire Universe or how we can tell this with certainty. So let’s take a deeper look to understand it’s age and significance.

What is the Methuselah Star?

The astronomers have been taking observations on the Methuselah star for roughly 100 years or more. According to them, it is positioned at some 190 light-years away from Earth in the Libra constellation close by the boundaryin the Milky Way Galaxy.. It rapidly travels across our universe at 800,000 mph. But the main reason for being widely known by the scientists and astronomers is that it holds certain traits that distinguish it from other stars and one of the emerging reasons is that it is older than the entire universe. You might be wondering about how this could even be possible, but research has revealed some encouraging facts of the same.

Methuselah star is a metal-poor sub-giant star whose apparent magnitude ranges to about 7.205. The star’s light is somewhat blueshifted as it is moving toward rather than away from us and it has been known to astronomers for over a century as a high-velocity star based on its other vectors such as proper motion. An early spectroscopic analysis by Chamberlain and Aller disclosed it to have a substantially lower metal content than the Sun. Even the modern spectroscopic analyses found an iron content about a factor of 250 lower than that of the Sun. It is one of the closest metal-poor (Population II) stars to Earth.

Is this star older than the universe?

Despite having the fairly estimate, we still don’t know and there might be a chance that we might never even know the exact age of the universe. According to NASA’s Wilkinson Microwave Anisotropy Probe (WMAP), the Methuselah star is 13.772 billion years’ old with an uncertainty of 59 million years. And according to the European Space Agency’s Planck spacecraft, it’s been around for around 13.82 billion years. And there are plenty of other estimates, in and around those figures.

We generally try to work out the age of the universe using two distinct methods. One being the tracking of the rate of expansion that the universe is undergoing and trace it all the way back to the Big Bang, and second of all, we search out the oldest stars in the sky.

If we have accurate data on the stars, then the second method works very well. Though, how do we really know how old are they?

Approximately, the age of a star is poles apart from guessing the age of a person. We can usually see and track the physical changes in most people when they age. And it even follows in the same way with most other creatures and plants and the same with most things we know to have a lifespan However, Stars don’t throw out the same clues.

From our standpoint on Earth, they have a tendency to look similar for most of their lives, which makes to even more hard to determine their age. But it is still possible as the scientists mostly focus on clusters of stars to discover the age of each of them. By knowing that the close cluster was made out of the similar material at around the similar time, they can subside each star’s differing masses and luminosities to come to an accurate evalation. This is the simplest scenario, but when a star isn’t in a cluster, it’s not quite so easy.

Expert astronomers can assemble some indication with main-sequence stars- again by analysing mass as well as the luminosity. However, there’s gyrochonology, which further entails working out a star’s age by its colour and spin of the star. The possibility for the mistakes are common with this particular method, however, as even slight uncertainties can translate to billions of miscalculated years. We are, at least, reasonably clear on our own star, majorly on the basis of its closeness to us. Among other ways, we have learned the age of the sun, which is some 0.6 billion years’ old by closely evaluating the radioactive elements found in meteorites else here in the solar system. Thus, he oldest known star with a reliably accurate age is officially known as HD 140283, but has also been dubbed “the Methuselah star.” Once dubbed the “Methuselah Star” by the popular press due to its age, if the assumptions of stellar evolution are correct in the report, the star must have formed soon after the Big Bang.

Age and significance

The biblical figure Methuselah is said to have lived for 969 years; which would comfortably make him the oldest human being ever. So, it’s not all that surprising then, that the oldest known star in the universe should go by the same name. But what is surprising is just how old Methuselah the astronomical object could be.

If you understand how stars work, you can observe the physical properties of one of them and envision its age, and know when it had to have been born. Stars sustain a lot of challenges and changes as they age especially in terms of their radius, luminosity, and temperature all evolve as they burn through their fuel.

Taken at stated value, the star’s predicted age raised a major problem and it further raised many questions such as: How could a star be older than the universe? Or, conversely, how could the universe be younger? It was certainly clear that Methuselah was old, since the metal-poor sub-giant is predominantly made of hydrogen and helium and contains very little iron. It’s composition means that the star must have come into being before iron became a commonplace.

Bond told that one of the unpredictability with the age of HD 140283 or the Methuselah star was the precise distance of the star and that It was getting highly essential to get this right as we can better determine its luminosity, and from that its age. The brighter the intrinsic luminosity, the younger the star will tend to be. They were in search of he parallax effect, which further explains that they were viewing the star six months apart to look for the shift in its location because of the orbital motion of the Earth, which tells us the distance.

There were also uncertainties in the theoretical modelling of the stars, just like the exact rates of nuclear reactions in the core and the significance of the elements diffusing downwards in the outer layers. They worked on the idea that leftover helium diffuses deeper into the core, leaving behind less hydrogen to burn via nuclear fusion. And with the faster usage of the fuel, the age of the stars will be lowered.

Another important fact which Bond talked about was the amount of oxygen in the star. HD 140283 had a higher than the estimated oxygen-to-iron ratio and, since oxygen will not be available in a large amount in the universe for a few million years, it pointed again to a lower age for the star.

Bond and his collaborators predicted the age of HD 140283 to be 14.46 billion years. A significant reduction on the 16 billion was previously asserted. That was, however, still more than the age of the universe itself, but the scientists constituted a residual unpredictability of 800 million years, which Bond said made the star’s age compatible with the age of the universe, even though it wasn’t entirely perfect.

Physicist Robert Matthews of Aston University stated that similar to all the measured evaluations, it is subject to both random and systematic error. Matthews said that the loopholes in the error bars give some indication of the probability of a clash with cosmological age determinations. So, when put differently, the best supported age of the star is in conflict with that for the derived age of the stars and the conflict can only be settled by pushing the error bars to their extreme limits.

Further filtration saw the age of HD 140283 fall a bit more. A 2014 follow-up investigation states that the star’s age to 14.27 billion years. The conclusion reached was that the age is about 14 billion years and, if again one includes all sources of uncertainty, then both in the observational measurements and the theoretical modelling, the error is about 700 or 800 million years, so there is no issue for 13.8 billion years lies within the star’s error bar.

Once the research had been supervised, Bond along with his fellow teammates predicted the age of the stars to be 14.46 billion years, which was an important decrement from the previously asserted age. That was, however, still more than the age of the universe itself, but the scientists constituted a residual uncertainty of around 800 million years, which Bond said made the age of the star look compatible with the age of the universe, even though it wasn’t entirely exemplary.

Although several scientists and people were doubtful, Bond and his fellow associates asserted that it was still be possible for the Methuselah star to be older than the universe due to several other reasons, including the precise distance. Bond stated that it is important to understand the distance because it will help discover its luminosity, and from that its age. Once scientists determine the luminosity of this star, its age will become much clearer to us.

Bond also added by saying that there were unpredictability in the theoretical modelling of the stars, just like the exact rates of nuclear reactions in the core and along with the significance of the elements diffusing downwards into the outer layers. This means that the certain rates of nuclear reactions found in the core of the star would play an essential role to help determine the age of the star.

Scientists still can’t decide with specifically if the star is older than the universe because the latter is constantly expanding. To this day, scientists have been debating over how old the universe is, but according to our rough prediction of 13.8 billion years old, the Methuselah star is older, meaning there has either been a crucial error in the calculations or we are missing a fundamental component.

Now, it’s always possible that there’s something fishy that happened in the star’s past that we can’t know about today. It’s possible that it was born as a higher-mass star and something emptied off the outer layers, diminishing the star’s lifetime fiercely. There might be a prevailing possibility that the star absorbed some material later-in-life which altered its heavy element content, misrepresenting our perceptions today. Or it’s possible that we’ve got a misunderstanding in the sub-giant phase of the stellar evolution of these old, low-metallicity stars. These unknowns are possible sources of errors when we try and compute the ages of the oldest stars.

You can’t have a star that exists in our Universe that’s older than the Universe itself. Either something’s wrong with our estimates for the ages of some of these stars, something’s wrong with our estimates for the age of the Universe, or something else, that we have yet to consider.

Conclusion

The mystery of the age of Methuselah star is leading to something bigger and more scientifically complex, influencing our understanding of how the universe works and its age. Currently, we can only tell from our calculations and our observations that the star is older, but one day, once if we find an error in our calculations, big or small, or find out an essential piece of information that we didn’t consider before, we will be able to tell exactly how old this star is.