Sharp eyes at the VLT - a decade of observations with NACO

November 25, 2011
Ten years ago, on 25 November 2001, the first adaptive optics system was installed at the Very Large Telescope (VLT) of ESO. Since then adaptive optics has become a routine observing technique, giving astronomers at the MPE and other institutes sharp eyes to observe the sky with ground-based telescopes and making many important astronomical discoveries.

Adaptive optics is a technique to remove the blurring of astronomical images due to the constant motion of the Earth's atmosphere by actively measuring the distortions and compensating for them. NACO was the first adaptive optics instrument to be installed on the VLT in 2001, and combined the Nasmyth Adaptive Optics System (NAOS) with the near-infrared camera CONICA.

In 1991, CONICA (COudé Near Infrared CAmera) was originally designed as a speckle camera, in which very short exposures are taken so that the effects of atmospheric distortion can be reduced when processing the images. The major advance, however, happened when the adaptive optics module NAOS was installed, providing the corrections directly on the fly during the observations. A world-wide unique feature of NAOS is its near-infrared wavefront sensor, allowing adaptive optics correction also for objects that are otherwise hidden behind interstellar dust. CONICA provides diffraction limited imaging, coronography, spectroscopy, and polarimetry in the 1 to 5 micrometre spectral range. It was built under ESO contract by a consortium of the Max Planck Institute for Astronomy (optics and cryo-mechanics) and the Max Planck Institute for Extraterrestrial Physics (detector and the readout electronics).

Some of the first targets for the new adaptive optics system NACO were objects of the Solar System such as the planets and their moons, but it also observed planets orbiting other stars. Observations with NACO also provided ultra-sharp images of the centre of our galaxy, revealing the orbit of a star around an unseen compact mass 4 million times larger than that of the Sun. These stunning observations of a team of MPE scientists lead by Reinhard Genzel proved the presence of a supermassive black hole at the centre of the Milky Way. Today, astronomers believe that almost all galaxies contain a supermassive black hole at their centre.

Links :
ESO Announcement about the 10-year anniversary of NACO

MPIA Press Release (2011-11-25)

CONICA pages at the MPE

ESO Release about First Light with NACO (2001-12-03)

ESO Release about Images of Saturn and Io with NACO (2002-01-31)

ESO Release about observations of stellar orbits in the galactic centre (2002-10-16)

ESO Release about the detection of the black hole in the galactic centre (2008-12-10)


letzte Änderung 2011-12-02 durch H. Steinle

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