On a clear night with high visibility, we can see many seemingly fixed luminous points in the sky, which are usually called stars. In fact, most of them are located in the Milky Way where the earth is located, and it is too far away that leads to such visual errors. As far as the essence of a star is concerned, it is actually the aggregation of spherical luminous plasma under the action of gravity. They have different stellar characteristics and generally have a life cycle of 500,000 to 1 trillion years. However, the star HD 140283 has provoked a puzzling space mystery, because our universe is about13.8 billion years old, and the age of this star may have exceeded14 billion years. So, why are there stars in the universe that are older than themselves, and what are the remarkable features of this planet?
What kind of planet is the ancient star HD 140283?
The star HD 140283, named methuselah, is about 190 light years away from our earth. Scientists have been observing the ancient star Libra. After 100 years of observation and understanding, we know that its speed when crossing the sky can reach 6.5438+0.3 million kilometers per hour, making it the oldest known star in the universe. In fact, the star HD 140283 is a critical celestial body between the giant star and the main sequence star. It is mainly composed of helium and hydrogen, and it is also a metal-poor subgiant. The iron content of this planet is even less than that of the sun 1%.
As early as 2000, scientists from the European Space Agency estimated that the age of this star was about 654.38+0.6 billion years. However, this amazing analysis results puzzled all of us. Because, from the observation data of the cosmic microwave background, even our universe is only about 65.438+0.38 billion years old, and the age of ancient stars is quite different from that of the universe. Why did the universe that should have appeared earlier become younger than this strange star? Although its almost iron-free star composition shows that the planet was born at least before iron became common in the universe, it is almost impossible to be born 2 billion years earlier.
How to solve the mystery of the exact age of stars HD 140283
In order to verify whether the age calculation of the star HD 140283 is wrong, scientists have made a detailed study on the observation results of11group from 2003 to 0. The data captured by the precise guidance sensor of Hubble Space Telescope contains important information such as the energy output, distance and position of stars. The determination of the age of this star combines photometric measurement, spectroscopy and parallax. The uncertainty of the age of the star HD 140283 is mainly caused by the distance factor. Accurate distance measurement plays an important role in calculating the age of stars. Distance value is closely related to luminosity. The stronger luminosity is, the younger the star is.
In order to find the parallax effect, scientists have observed the star HD 140283 for six months. Through the displacement of the earth's position caused by its orbital motion, scientists know more accurate distance information. At the same time, the oxygen content in this ancient star will also affect the judgment of its age. The actual "iron oxide" content in the planet exceeds the researchers' expectations, which also means that the age of this star should be lower to be reasonable. Finally, scientists set the age of HD 140283 as about14 billion years. Although this life span has exceeded the age of our universe itself, researchers have given an uncertain age difference of 800 million years. Although this result doesn't look perfect, it makes the age of the universe more consistent with the age of the star HD 140283.
The age difference between the universe and the star HD 14028.
As mentioned just now, the calculated age of the star HD 14028 is obviously different from the deduced age of the universe, and the overlapping part of the error can explain the conflict between the age of the star and the age of the universe to some extent. When the age of the universe determined by the cosmic microwave background conflicts with the possible age of stars, the only way for scientists to solve this conflict is to minimize the error between them. In fact, there may be some errors in any research results of scientists, which may be random or systematic errors. However, with the age of the star HD 140283 decreasing continuously and the time error of 800 million years caused by uncertainty, the cosmic age of1380,000 is already within the error range of the age of the star HD 140283.
Compared with decades ago, because scientists have a better understanding of the uncertainty in cosmic events, the calculated ages of celestial bodies are relatively consistent, and there have never been any ancient stars over 65.438+0.8 billion years old. In fact, the age of stars born very early is bound to have a high similarity with the age of our universe, but they are all one of the best evidences of the Big Bang. Although there are still many questions about the age of the universe and the celestial bodies located in it, for example, the data of nearby galaxies also show that there is an error between the age of the universe and the age determined by the microwave background, all this will be further confirmed in the future.
Why can the history of a star exceed 65.438+0.4 billion years?
Why is there an older-looking star in the universe? In fact, there are many factors behind such data results, whether it is the blank in the existing universe dynamics, the main driving force of the expansion of the universe, or the sources that scientists have not yet understood, which may bring errors to the observation, which may lead to a certain range of uncertainty in determining the age of objects. Moreover, the problem of age error that we are encountering now may be the performance of dark energy changing with time, which leads to the acceleration of the response of the change rate. The basic nature of gravity conforms to this possibility conceptually, so scientists' new research on gravitational waves may help solve the existing paradox.
In order to solve this situation, we can no longer rely on the detection of supernovae, Cepheid variable stars or cosmic microwave background to measure Hubble constant, but need to study the "death stars" that cause ripples in the space-time structure. Of course, measuring gravitational waves is not an easy task. This process needs to collect the collision data between pairs of neutron stars, and use the visible light emitted when the event occurs to determine the moving speed of the target star phase relative to the earth. After analyzing gravitational waves, the actual distance is obtained, and the measured value of Hubble constant is obtained by combining speed and distance, so the measured value should be relatively more accurate. Although the appearance of the star HD 140283 further expands the mystery of the universe, it gives us a deeper understanding of the operation of the universe and will prompt mankind to seek an answer closer to the truth in the future.
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