Why have scientists found Proxima b - '2nd Earth' until now?

Over the past two decades, astronomers have discovered more than 3,200 " exotic " planets or planets outside our solar system . They found the giant gas planet, rocks, " Earth " -style planets and " Tatooine " planets - the planet has two suns. Furthermore, they discovered the " strange " planet more than 13,000 light-years from Earth. But now, scientists still have not determined the exact size of the " Second Earth " - the habitable planet, even it is called the human existence universe.

A composite picture of the diagrams of stars Proxima Centauri, Alpha Centauri A and Alpha Centauri B with Milky Way Milky Way ( Milk Road ) and ESO's 3.6 m diameter telescope at La Silla Observatory at Chile.Photo source: ESO / Pale Red Dot

On August 24, astronomers announced that they had discovered a " strange " Proxima b orbiting Proxima Centauri - a red dwarf just four years from Earth we live in. light and the star closest to the Sun. So why have scientists found Proxima b - " 2nd Earth " until now?

It is because they are trying to find enough information about it. (6 strange facts about Proxima Centauri b - "Second Earth" you may not know yet)

" I'm going to find out the truth about Proxima b, " said Michael Endl , an astronomer at the McDonald Observatory at the University of Texas at Austin.

Endl - a member of the research team - who previously ran a seven-year research campaign in the early years of the 21st century. They searched for planets that were about the same weight as the Earth - okay called the " Second Earth " - the habitable zone is orbited around Proxima Centauri - observed at the European Southern Observatory (ESO ) with a very large telescope ( Very Large Telescope ) in Chile. After returning, he still could not find any more planets there.

" We can find a planet that weighs two to three times the weight of Earth - an area where life exists, " Endl said. This " strange " planet is 1.3 times the weight of the Earth - located just below his radar ( or telescope ).

Because it is the closest to the Sun, Proxima Centauri seems to be a suitable place to discover " strange " planets - where scientists understand them. But so far, Endl researchers' breeding campaigns still seem to have failed to produce any results.

New planets like Proxima b are difficult to discover, because it is a relatively small world, revolving around a small star - the star is too dim to be seen with the naked eye when standing from our Earth. . To find this " strange " planet, scientists must have a specialized and intensive campaign to detect those weak signals.

Guillem Anglada-Escude - an astronomer at London's Queen Mary University - the head of the research team said: " Within 10 years, using high-tech technology we can find and discover. This new planet is not a method or technical issue . "

Determine movement

Planets can create gravitational gravity on the host star as they orbit around, allowing the star to move around the center. Astronomers can measure this shift with an effect called the Doppler effect - which describes the change in the wave frequency when its source moves in the same or opposite direction to the observer. .

Endl researcher explained: " The police's high-speed specialized radar gun uses this effect to quickly detect how fast a car moves. Astronomers can make one. Similar experiments using telescopes to measure the speed of light of a star When a moving star is facing us, its light appears to shift in blue at the end. of the spectrum, and when the motion is opposite to us, the light will turn red . "

Even a small planet like Proxima b could cause the translating Proxima Centauri star to become fuzzy, but small changes in the speed of the star could reach the limits of things. Search by astronomical tools today.

Proxima b orbiting the master star Proxima Centauri took 11.2 days. During that cycle, Proxima Centauri moved slowly toward Earth at a speed of about 5 km / h ( 3 mph ) - that is the average speed of a pedestrian and then, off the Earth as well. with the same speed.

During the observation of Proxima Centauri in 2013, Anglada-Escudéhad showed faint signs in this 11-day cycle.

Endl said: " But at the time, the data was not convincing enough to confirm Proxima Centauri had another planet. In general, there are many mystery stories behind these data ." For example, the signal comes from the stars themselves - this provides important data for research.

"Pale red dot" or "Light red dot"

To eliminate possible possibilities, Anglada-Escudéthen and 30 other scientists came up with a search system, dubbed the " light red dot " or " Pale red dot " campaign. Carl Sagan - a famous astronomer and astrophysicist used the name " pale blue dot " - a description of our Earth. The tiny blue dot appeared in an iconic image of the solar system that was put into use on February 14, 1990, using NASA 's space probe during the return trip. stars in space. In contrast, a light planet of Proxima Centauri will be immersed in red light.

Between January 18 and March 30 this year at the ESO Astronomical Observatory in Chile, Anglada-Escudé and his colleagues discovered a " strange " planet named Proxima b. around Proxima Centauri . The main equipment used by the team is the HARPS ( High Accuracy Radial Velocity Planet Searcher ) - not used to search for a Doppler symbol in a Blurred star like Proxima Centauri red dwarf. The study was conducted in Proxima Centauri because this red dwarf is very close to our Earth.

From these observations, the researchers determined the weight of the " strange " planet Proxima b, close to our Earth's weight and this " strange " planet in the region could live, meaning that it is suitable for survival. They continue to study further to find out whether the reality on the surface of the planet Proxima b has air and water - this feature helps it resemble our existing Earth.

Further research can be conducted on Proxima b by searching for " strange " planets similar to seeing if Proxima b " passes " in front of Proxima Centauri star when viewed from the Earth's perspective.

Anglada-Escudé said: " Right now, we know about this" strange " Proxima b planet, so we can predict when Proxima b will be able to surpass the host of Proxima Centauri . it will be a very interesting thing . "

This technology is used to detect Proxima Centauri host star but without any luck. The search team said: " In fact only 1.5% of Proxima b's chance will pass. However, if Proxima b passes, scientists will measure the spectrum of light from the throne. stars connecting through the atmosphere of Proxima b - which may contain important clues about this "strange" Proxima b chemical structure . "

Endl added: " We all wonder if there is actually a" Second Earth "capable of living and when approaching the stars it will help us to see more clearly about this planet ".