Over the centuries, humans have asked the planets that exist around other stars and dream of what these foreign worlds can be like.
Eventually technology began to catch up with our imagination. Although a lot of false And the dead all the time, Astronomers announced the first discovery of Exoplanet in 1992. These planets were not like the earth, nor orbits a star like the sun, but they confirmed that they exist. The worlds outside the solar system were the first evidence that ever found.
But the first proofs were earlier in 1988, when astronomers approached a planet, Gamma Cephii A, 45 years old, 45 years of light announced. This claim was later back due to data uncertainty. In 2003, however, More observations showed that the planet existed. Believed this The first evidence of foreign worlds were, or you believe in so many textbooks and articles.
To help Science Journalism
If you enjoy this article, consider entering award-winning journalism Subscribe. By purchasing subscription, you are helping to ensure the future of stories about the discoveries and ideas that are conformed to today.
But that’s not quite true. In a paper published in the procedures of an astronomical lectureBen Zuckerman American astronomer showed that The first evidence was found much earlier than that.
In 1917, American astronomer Americans Adriaan Van Maan’s American astronomer was looking for stars in space. To do this, he searched the stars that had the right movement, which was moved faster during the sky than the surrounding stars. The idea is that the stars closer to the earth move farther away, the side trees of a road are faster when you are zip the car.
Found oneAnd it’s been curious. At that time observations stated that he was close to Decit, about 13 light years. (Modern measures are placed in 14.1.) But that didn’t make sense: These observations also stated that it was a hot starHeater than the sun, and these types of stars are very bright. However, it was later called Van Maanen 2, it was very dark. Based on only the temperature, it should be among the brightest stars visible in the sky, but it was so weak that he could not see without telescopes!
Over the next decades, this mystery was fixed. Van Maan’s 2 is an example of a white dwarf, a footprint of a relatively low mass of mass like the sun. Then, after all the fuel in his core runs out, it expels the red red giant and external layers. What remains the hot field exposed to space. It looks like an ordinary star from a distance, and the temperature has a much bigger mass. The small white dwarf is small, but it is very compact, squeezed only as much mass of our sun to the size of the Earth! A cubic centimeter of white dwarf material can weigh as many as a metric size of a six-sided month ton-This is 100,000 times as compact as lead.
Van Maanen 2 is the lonely white dwarf with the sun, so it is very strongly studied. (Others are closer but the orbits are other stars.) White dwarfs are so weak that are difficult to learn at greater distances, and it’s so close to have a boon of astrophysics.
But such studies revealed another mystery on this star. The astronomers can study the various features of a cosmic object to create spectra, in the multi-wavelength (or color) input light. Different elements and molecules absorb light in very specific wavelengths, so it is to measure the presence of these materials with the stars, looking for less light spectrum sites. (These features are called an absorption line.) Time van Maanen 2 was found, like such spectras were recorded in a similar fashion; The light of the telescope was screened on a glass plate and was soaked with sensitive chemicals.
When astronomers examined Spectrum or van maanen 2 They were amazed to see in one of these places Spectral features It usually associates with much massive stars, namely, a strong calcium absorption line in the atmosphere of the star. In the eyes of a modern astronomer, it is very strange.
Calcium should not be in the atmosphere of white dwarf; The Stellar body has a large surface gravity. Standing on the surface, a typical human being would weigh about 7,000 metric tons, more than 20 times of the state of freedom! Despite the intense gravity, a white dwarf can have an atmosphere with almost very hot hydrogen and helium. Heavious and less harder elements, iron or calcium, should fall to the surface quickly in astronomical time to clean the atmosphere. In fact, most white dwarfs see that atmospheres with two lighter elements are very empty.
But they are not all “infected” being heavier elements, being the first example of Van Maan’s 2 science. The next piece of this exoplanine puzzle fell in the early 2000s Astronomers found “excess excess” for some white dwarfsThe foam; That is, these white dwarfs give more infrared than expected. Such things have been seen in normal stars and flows infrared the infrared presence of an illuminated waste disk. For white dwarfs, this result was unexpected, but the remains of the asteroids torn with the hard gravity of the dead stars were accelerated quickly. The asteroids themselves are likely to be part of the process of forming the planet that occurred in thousands of millions of years ago, when the white dwarf was a young and intense star like the sun. After the star was killed, the asteroids could record the giants of gas planets in any orbit and violated. Over time, the rich waste ruins of the elements fell down the white dwarf, polluting the atmosphere.
Many of these white dwarfs are old, but they still show this waste signature in the spectrum. This means that the rainwaste is a continuous process of rainwaste! Otherwise, the heavier material has long been cleaned from the atmosphere.
And this Why was Van Maanen’s 2’s calcium-spiked spectrum was so strange: in addition to imitating a warmer star, it was also infected with the waste of an ancient planet system.
In the ground world war, the world war happened in the world for about 14 light years. A small light spark collected by a telescope and recorded on a small glass plate that the planets existed around other stars.
In some sense, foreign worlds were not found in the first 1990s or found in the 1980s. It took almost a century to fully understand, but the first evidence of Exoplanet were found in 1917.
