Anglada-Escudé and his colleagues found that, Proxima Centauri sometimes approaches Earth at a speed of about 5 km/hour (3.1 mph) and sometimes moves away at a similar pace.
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It is also the target of the Starshot project, which aims to create and send ultra-fast light-driven nanocraft that would reach the system 20 years after launch and beam home images. The fact that this planet is this close to Earth is incredible.
Guillem Anglada-Escude, an astrophysicist at the Queen Mary University of London was the lead author of a study on the discovery in the scientific journal Nature.
The first signals of a world orbiting Proxima Centauri were recorded more than a decade ago, and more such signals have continued to trickle in – but never enough to be convincing. The parent star was observed earlier this year using the HARPS spectrograph at the ESO. The star pelts its planet with powerful ultraviolet rays and X-rays, which would mean that anything living there would find it much harder and so would have to become hardened against that radiation.
The Pale Red Dot campaign is the name given to an effort to detect Earth-like planets orbiting Proxima Centauri, and the researchers involved provided regular online updates of their progress through their website and social media. Given the size, it’s likely that Proxima b has a solid rocky surface, but the truly fascinating thing is that it is in the habitable zone of its star. However, Proxima is 1,000 times fainter than the Sun.
Scientists discovered Proxima b thanks to what’s known as the radial velocity method, which takes advantage of the Doppler effect.
No existing instrument could snap such pictures.
The Alpha Centauri system, discovered in 1915, is part of the Centaurus constellation and is so close that you can actually see its other two stars – Alpha Centauri A and Alpha Centauri B – in the night sky.
Professor Richard Nelson, from Queen Mary, University of London – a member of the global team that announced the discovery in the journal Nature, said: “Finding a planet around the star which is the nearest to the Sun is a big event”.
Jupiter is our biggest planet.
According to a Nasa study published in 2000, a giant laser sail measuring 200 miles in diameter could make the trip to Proxima Centauri in just over 12 years.
The next generation of telescopes will help astronomers probe the potential atmospheres of Proxima B and exoplanets like it.
In some ways, this is simpler to do with M dwarfs; because they’re much smaller than stars like our sun, they’re also more easily pulled this way and that by their planets.
Other planets outside our solar system have been announced with fanfare, only to quietly fade away when they couldn’t be confirmed.
It comes down to an understanding of the star this planet orbits, as well as how data collection has evolved during the last 16 years.
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“A planet around even a wimpy star like Proxima Centauri is going to be more than a billion times fainter than the star itself”. Is anybody allowed to toss an M dwarf star?!
