Spectro-Polarimetric High-Contrast Exoplanet Research
Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT-SPHERE) is an adaptive optics system and coronagraphic facility at the Very Large Telescope (VLT).
The instrument operates in the visible and near infrared, achieving exquisite image quality and contrast over a small field of view around bright targets.
These instruments combine extreme adaptive optics with high-efficiency coronagraphs to correct for the atmospheric turbulence at high cadence and attenuate the glare from the host star.
In addition, SPHERE employs differential imaging to exploit differences between planetary and stellar light in terms of its color or polarization.
[4] The Large Binocular Telescope, equipped with a less advanced adaptive optics system, has successfully imaged a variety of extrasolar planets.
SPHERE (black container and silver cylinder) attached to the telescope from the adjunct platform
The star HR 7581 (
Iota Sgr
) was observed in SPHERE survey mode. A very low-mass star, more than 4000 times fainter than its parent star, was discovered orbiting Iota Sgr at a tiny separation of 0.24". The bright star itself has been suppressed almost completely by SPHERE, to allow the faint companion to appear as a clear bright spot to the upper right of the centre.
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.
