AMBER, the VLTI near-infrared instrument: Design, status and scientific applications.

AMBER is the near-infrared instrument being built for the VLT Interferometer by a consortium of several institutes in France, Germany and Italy. Its key characteristics include: the ability to combine two or three beams, allowing closure phase; a wavelength range that initially will cover the near-infrared from 1 to 2.4 mu m, possibly to be extended later towards shorter and longer wavelengths as well; variable spectral resolution up to approximate to 10(4); the potential for high accuracy visibility measurements, thanks to a fiber-based beam combination scheme. We review the concept and design of the instrument, implementation schedule and predicted performance. Thanks to the large photon-gathering power and multiple baselines of the VLTI, AMBER will permit to observe a wide range of sources. We review its application in some key areas of research which will include: hot exoplanets, young stars, AGB and late-type giant stars, binary stars, hot luminous stars, AGN and extragalactic sources.