ESO's newest planet hunter, ESPRESSO, captures first light

By Brooks Hays

Dec. 6 (UPI) -- ESPRESSO, the European Southern Observatory's newest planet hunter, has captured its first light.

ESPRESSO, short for Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, is installed on ESO's Very Large Telescope. The next-generation instrument is the successor to HARPS, ESO's original planet hunter.


HARPS achieved first light in 2003 and has discovered more than 150 new planets during its career. The instrument can measure velocity with a precision of one meter per second. Its successor, the newest echelle spectrograph, expects to measure velocity with a precision of a few centimeters per second.

Now situated on VLT at the Paranal Observatory in northern Chile, ESPRESSO is looking for the tiniest of changes in the light of distant stars, evidence of stellar wobbling caused by the gravitational pull of even the lightest, smallest exoplanets.

ESPRESSO and its laser frequency comb are designed to look for small, rocky planets in the habitable zones of relatively cool and dim stars, including G dwarfs and red dwarfs.

"This success is the result of the work of many people over 10 years," Francesco Pepe, lead ESPRESSSO scientist and a researcher at the University of Geneva in Switzerland, said in a news release. "ESPRESSO isn't just the evolution of our previous instruments like HARPS, but it will be transformational, with its higher resolution and higher precision."


The new planet hunter can utilize all four of VLT's telescopes.

"ESPRESSO will be unsurpassed for at least a decade -- now I am just impatient to find our first rocky planet!" Pepe said.

But the march of astronomical technology doesn't rest. Scientists and engineers are already working on the next planet hunter, the instrument HIRES. It will be installed on ESO's Extremely Large Telescope when its construction is complete. First light is planned for 2024.

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