26 years ago there was an article about the first exoplanet
Why the astronomer received applause from his colleagues for his mistake, how the first exoplanet was discovered, followed by several more first ones, Indicator. Ru tells in the "History of Science" section.
Usually, notes from the heading "History of Science" are devoted to successes: successful inventions, discoveries, the creation of something that is remembered several centuries later. Today is one of those cases where a mistake deserves attention. Moreover, it was discovered not after the death of the author of the discovery, but he himself found it. This disgraceful recognition deserves approval - not only of his colleagues, but also of us.
In 1967, British astronomer Andrew Line was preparing his dissertation at the Jodrell Bank Observatory. In the same year, they announced the discovery of a new class of objects - pulsars. This news impressed our hero, Line put aside his work and started looking for neutron stars. His group of researchers turned out to be quite successful: their article, which was devoted to the search for pulsars, became the second in history, coming out just a few weeks after the article by Jocelyn Bell, one of the discoverers of these astronomical objects.
Jocelyn Bell / Roger W Haworth / Wikimedia Commons
After completing his dissertation, Line again returned to neutron stars. At the Jodrell Bank telescopes, he and his colleagues were able to find several pulsars. In 1985, they saw the PSR 1829-10 for the first time. A little later, astronomers noticed that there were deviations in the regularity of the bursts of its radiation that they could not explain. Having considered different options, scientists came to the conclusion that these fluctuations are caused by a planet revolving around the pulsar.
According to calculations, the mass of the newly discovered celestial body should have been no more than the mass of Uranus, but the astronomers were worried about something else: the period of the planet's revolution was about six months, that is, half of the earth's year.
How did you search for this planet and what is the problem with such a period? The assumption that a celestial body revolves around the pulsar was based on deviations in the "mode" of bursts of its radiation. Such deviations can be caused by the rotation of a neutron star around a common center of gravity with the planet (and movements either toward the Earth or away from it), due to which, in accordance with the Doppler effect, the pulse frequency periodically changes.
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So, perhaps, the brightness fluctuations were associated with the movement of the Earth in its orbit, and not the pulsar around its center of gravity, which is common with the planet? It was not difficult to make a mistake here, and astronomers tried very hard to rule out such a possibility. The result depended on the accuracy of measurements and calculations. Fortunately, computers were already considered then, on the basis of the developed model, but the situation with measurements was more complicated. Claiming the discovery of a planet required data accuracy within the capabilities of the time and a long observation period. Unsurprisingly, astronomers hesitated and checked the results for months before deciding to announce the discovery.
Planets in pulsar systems have not been spoken about since 1979, when such a claim was not confirmed, so the discovery of Line and his co-authors hit the covers and front pages: the first exoplanet was found! However, skeptics were quickly found who also drew attention to the suspicious period of the planet's circulation, but Line's meticulousness convinced most of them that the calculations were correct.
Andrew Line / Mike Peel / Wikimedia Commons
Almost six months have passed since the article was published. At the end of December 1991, Line decided to return to his calculations. Something in the records made him doubtful, and the astronomer revisited the data and ran the calculations on the computer, slightly adjusting the model. And the result of the calculations clearly showed: there are no deviations. The reason for the discrepancy between the results turned out to be that the model that Line used for the calculations did not take into account the difference of the Earth's orbit from the correct circle - something that can sometimes be neglected, entailed a serious error.
Realizing the significance of the new result, Line decided as soon as possible to admit that the past high-profile discovery was a mistake. The opportunity was the Atlanta conference.
“On January 15, 1992, Andrew Line took the stage and began his speech. Except for a few muffled voices, there was silence in the room, a silence of disappointment. The Briton finished his report by asking forgiveness from the entire scientific community. He barely had time to finish when the audience burst into applause. Obviously, the audience appreciated the courage of their unfortunate colleague,”the authors of one of the books devoted to the search for exoplanets described this speech.
The Polish astronomer Alexander Volzhan spoke at the same conference. He talked about two (or maybe three) exoplanets in the PSR 1257 + 12 pulsar system. One of them became the first discovered planet outside the solar system, the existence of which was later confirmed. With this proof, obtained in 1995, the phase of fruitless searches and errors ended. At the moment, scientists have already found more than 3500 exoplanets and are not going to stop there.