The European Southern Observatory (ESO) has signed an agreement with the Breakthrough Initiatives to adapt ESO’s Very Large Telescope instrumentation to conduct a search for exoplanets in the Alpha Centauri system.
This image shows the closest stellar system to the Sun, the bright double star Alpha Centauri AB and its distant and faint companion Proxima Centauri. Image credit: ESO / B. Tafreshi, twanight.org / Digitized Sky Survey 2 / Davide De Martin / Mahdi Zamani.
The agreement between ESO and the Breakthrough Initiatives provides funds for the VLT Imager and Spectrometer for mid-Infrared (VISIR) instrument, mounted at the Very Large Telescope (VLT), to be modified in order to greatly enhance its ability to search for exoplanets in Alpha Centauri.
The agreement also provides for telescope time to allow a careful search program to be conducted in 2019.
The recent discovery of the Earth-mass exoplanet Proxima b adds even further impetus to this search.
Knowing where the nearest exoplanets are is of paramount interest for the Breakthrough Starshot project, which aims to demonstrate proof of concept for light-driven nanocraft, laying the foundation for the first launch to Alpha Centauri within a generation.
Detecting a habitable exoplanet is an enormous challenge due to the brightness of the planetary system’s host star, which tends to overwhelm the relatively dim exoplanets.
One way to make this easier is to observe in the mid-infrared wavelength range, where the thermal glow from an orbiting exoplanet greatly reduces the brightness gap between it and its host star.
But even in the mid-infrared, the star remains millions of times brighter than the planets to be detected, which calls for a dedicated technique to reduce the blinding stellar light.
The existing mid-infrared instrument VISIR will provide such performance if it were enhanced to greatly improve the image quality using adaptive optics, and adapted to employ a technique called coronagraphy to reduce the stellar light and thereby reveal the possible signal of potential terrestrial planets.
Breakthrough Initiatives will pay for a large fraction of the necessary technologies and development costs for such an experiment, and ESO will provide the required observing capabilities and time.
