ESO and the Breakthrough Initiatives team up to search for extrasolar planets next door

A new partnership will increase the sensitivity of the VLT so it can look more closely at the Sun’s closest stellar neighbors, paving the way for a potential future flyby.
By | Published: January 9, 2017
An artist’s impression of Proxima b, a planet slightly more massive than Earth orbiting within the habitable zone of the red dwarf Proxima Centauri. The image also shows Alpha Centauri A and B as a double star in the distance.
ESO/M. Kornmesser

The search for exoplanets and the life they could harbor has captured the interest of professional astronomers and the public alike. Now, the European Southern Observatory (ESO) and the Breakthrough Initiatives have signed an agreement that will allow the ESO’s flagship facility for ground-based astronomy to search for habitable planets around the Sun’s nearest neighbors.

ESO Director General Tim de Zeeuw and Executive Director of the Breakthrough Initiatives Pete Worden have reached an agreement that will allow the ESO’s Very Large Telescope array (VLT) to conduct a search for potentially habitable planets in the Alpha Centauri system, which lies approximately 4.3 light-years from Earth.

This agreement comes just months after the publication of a paper in Nature announcing the discovery of a planet approximately 1.3 times as massive as Earth orbiting Proxima Centauri, a red dwarf and the closest of the system’s three stars to the Sun. The planet, Proxima b, is located within Proxima Centauri’s habitable zone, a region of space around a given star where the temperature is just right for liquid water — and thus life recognizable to those of us on Earth — to exist.

Searching for exoplanets is challenging for many reasons. When compared with their nearby parent star, even large planets pale in comparison to the amount of light put out by their sun. Techniques such as observing in mid-infrared wavelengths and carefully blocking out the light from the parent star are thus used to improve the detectability of planets.

This new agreement allocates both funding and telescope time that will allow the VLT Imager and Spectrometer for mid-Infrared (VISIR) instrument to more effectively detect planets with the potential for life in this nearby stellar system. Projected improvements include the addition of adaptive optics to stabilize image quality and coronagraphy techniques that will reduce stellar light to allow astronomers to more easily capture the light from an orbiting planet.

Once these changes are made, a search program to identify planets around Alpha Centauri is scheduled to begin in 2019. Not only will these developments allow astronomers to find yet-undiscovered planets circling some of our Sun’s nearest neighbors, they will also provide proof of concept for the METIS instrument, which will be mounted on the ESO’s 39m (128ft) European Extremely Large Telescope (E-ELT). The E-ELT is scheduled for first light in 2024, and could find planets as small as Mars at the distance of Alpha Centauri.

In addition to the recent detection of Proxima b around the system’s red dwarf, astronomers announced in October of 2012 that they had discovered a planet orbiting the main sequence star Alpha Centauri B. Although this result was later challenged, the potential for more planets hiding within the Alpha Centauri system remains.

In 2015, Yuri and Julia Milner founded the Breakthrough Initiatives to further space exploration with the goal of finding evidence of life beyond the Earth. In 2016, the Breakthrough Initiatives launched their $100 million Breakthrough Starshot program, designed to provide proof of concept for extremely small light-driven “nanocraft” that could pave the way to a launch to Alpha Centauri. These unmanned nanocraft could potentially reach speeds of up to 20% of the speed of light, allowing them to reach the Alpha Centauri system within a generation.