Black hole

What lies at the centre of the Milky Way? For a long time, astronomers have suspected that a black hole lurks at the heart of our Galaxy, but could not be sure. After years of regular monitoring of the Galactic Centre with ESO telescopes at the La Silla Paranal Observatory, scientists finally obtained conclusive evidence.

"We needed even sharper images to settle the issue of whether any configuration other than a black hole is possible and we counted on the ESO VLT to provide those. Now the era of observational black hole physics has truly begun!"
– Reinhard Genzel, Director at the Max-Planck Institute for Extraterrestrial Physics

ESO's adaptive optics facilities have obtained top-notch scientific results. These include the first direct observations of an extrasolar planet near a bright star, as well as key characterisations of the black hole at the centre of the Milky Way.The next generation of adaptive optics is on the way for both the VLT and the Extremely Large Telescope (ELT), with support courtesy of European Commission research funding contracts. Projects slated for the VLT include the use of several laser guide stars at once, as well as advanced adaptive optics instruments such as the SPHERE planet finder. Also under development are advanced systems tailored to meet the challenges of the ELT, which will have a revolutionary 40-metre-class diameter primary mirror. Significant recent progress has also paved the way for attaining a wider corrected field of view, a result that will have an impact on the design of future VLT and ELT adaptive optics systems.

Exoplanets

The search for planets outside our Solar System constitutes a key element of what is possibly the most profound question for humanity: is there life elsewhere in the Universe? ESO's observatories are equipped with a unique arsenal of instruments for finding, studying and monitoring these so-called 'exoplanets', or 'extrasolar planets'.Using the Very Large Telescope, astronomers were able for the first time to spot the faint glow of a planet outside our Solar System, taking the first ever picture of an exoplanet. This new world is a giant one, some five times more massive than Jupiter. This observation marks a first major step towards one of the most important goals of modern astrophysics: to characterise the physical structure and chemical composition of giant and, eventually, terrestrial-like planets. The VLT has also played a crucial role in the discovery of a system of seven Earth-sized planets orbiting a star just 40 light-years away, TRAPPIST-1. Three of the planets lie in the habitable zone and could harbour oceans of water on their surfaces, increasing the possibility that the star system could play host to life. This system has both the largest number of Earth-sized planets yet found and the largest number of worlds that could support liquid water on their surfaces.

"The tiny signals discovered by HARPS could not have been distinguished from the 'simple noise' by most of today's available spectrographs." – Michel Mayor, Geneva Observatory, co-discoverer of the first extrasolar planet around a main-sequence star.

Gamma Ray Bursts

Gamma-Ray Bursts (GRBs) are bursts of highly energetic gamma rays lasting from less than a second to several minutes – the blink of an eye on cosmological timescales. They are known to occur at huge distances from Earth, towards the limits of the observable Universe.

One of the currently most active fields of astrophysics is the study of the dramatic events known as "gamma-ray bursts (GRBs)" . They were first detected in the late 1960's by sensitive instruments on-board orbiting military satellites, launched for the surveillance and detection of nuclear tests. Originating, not on the Earth, but far out in space, these short flashes of energetic gamma-rays last from less than a second to several minutes.Despite major observational efforts, it is only within the last six years that it has become possible to pinpoint with some accuracy the sites of some of these events. With the invaluable help of comparatively accurate positional observations of the associated X-ray emission by various X-ray satellite observatories since early 1997, astronomers have until now identified about fifty short-lived sources of optical light associated with GRBs (the "optical afterglows").Most GRBs have been found to be situated at extremely large ("cosmological") distances. This implies that the energy released in a few seconds during such an event is larger than that of the Sun during its entire lifetime of more than 10,000 million years. The GRBs are indeed the most powerful events since the Big Bang known in the Universe.