ESO’s SPHERE achieves first light

The observatory's new exoplanet imager shows promise

This infrared image shows the dust ring around the nearby star HR 4796A in the southern constellation of Centaurus. It was one of the first produced by the SPHERE instrument soon after it was installed on ESO’s Very Large Telescope in May 2014. It shows not only the ring itself with great clarity, but also reveals the power of SPHERE to reduce the glare from the very bright star — the key to finding and studying exoplanets in future.

The ring of dust around the nearby star HR 4796A was one of the first things to be imaged by SPHERE. Credit: ESO/J.-L. Beuzit et al./SPHERE Consortium

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The European Southern Observatory (ESO) has released the first images to be taken by SPHERE, a brand new exoplanet imager installed on the Very Large Telescope.

SPHERE will be used to locate and image exoplanets using some of ESO’s most advanced technology.

It is hoped the new instrument will transform the way exoplanets and circumstellar discs are studied with SPHERE providing the best direct planetary images ever captured.

Jean-Luc Beuzit was SPHERE’s principal investigator, “SPHERE is a very complex instrument. Thanks to the hard work of the many people who were involved in its design, construction and installation it has already exceeded our expectations.”

In order to find and characterise exoplanets orbiting nearby stars through direct imaging, a technique very different to that of NASA’s Kepler Space Telescope, SPHERE has been designed to image using the highest contrast possible over a very small patch of sky.

This way the light from a planet’s parent star won’t flood the image and obscure the planet.

To do this SPHERE uses three techniques.

Extreme adaptive optics are used to correct the distorting effects of Earth’s atmosphere keeping images sharp and well-contrasted.

A coronagraph is used to block out starlight and a technique called differential imaging picks up the differences between the colour and polarisation of planetary and stellar light.

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Several targets were chosen to test SPHERE including the ring of dust around the nearby star HR 4796A.