4.37 light-years away lies the Alpha Centauri system. What lurks near our closest stellar neighbor? A big announcement last August revealed a planet in the habitable zone around the star. But its close orbit (just 11 days) means the chances of life on the planet are small. While the orbit might be temperate due to the nature of the Proxima Centauri (a red dwarf), the proximity means it’s probably being slammed by ultraviolet and X-ray flares from the star. A no-go for life. At least, as we know it.
But the discovery does make astronomers wonder what other chunks of rock are orbiting the three stars making up Alpha Centauri. The European Southern Observatory (ESO) agrees and plans to adapt the Very Large Telescope to conduct a more thorough search for planets in the star system in 2019.
The ESO and Breakthrough Initiatives entered into an agreement to modify the telescope to enhance its ability to discover planets around our nearest solar system.
Detecting planets in a habitable zone around another star is no easy feat. Because the habitable zones are often close to the star, the star’s blinding brightness makes it difficult to spot. Astronomers look at stars through the mid-infrared wavelength range to help tamp down the brightness from the star. Even then, the star can still be millions of times brighter than the planets.
That’s where the upgrade ESO and Breakthrough Initiatives comes into play. Using adaptive optics and a technique called coronagraphy (reduces the light from the star even more).
A coronagraph is a disc attached to a telescope that blocks the bright light from a star. Here’s how it looks when the Solar and Heliospheric Observatory looks at the sun.
Breakthrough Initiatives will provide most of the money for the tech upgrades while ESO provides the telescope and the time for the search. Among the new upgrades will be an instrument module, “which will host the wavefront sensor, and a novel detector calibration device.” A new coronagraph, like the one seen in the image above, is also being developed.
Alpha Centauri provides a unique opportunity for the ESO right now. The upcoming European Extremely Large Telescope (E-ELT) is designed to detect and study potentially habitable planets. But it won’t be ready until the mid-2020s. The Very Large Telescope isn’t as powerful as the E-ELT, but it has enough power to detect and study large planets around the closest star system to Earth.
The Very Large Telescope could find planets we don’t know about yet, but the E-ELT will be the one to watch for. The METIS (mid-infrared imager) on the E-ELT will be able to detect exoplanets the size of Mars orbiting Alpha Centauri, if they are out there.
The search for exoplanets like Earth will only heat up as more sophisticated telescopes are brought online. 2019 might not bring the announcement of a planet the size of Earth, but it could tell us the Alpha Centauri system has more planets than we know about right now.