GREGOR is a solar telescope, equipped with a 1.5 m primary mirror,[1] located at 2,390 m altitude at the Teide Observatory on Tenerife in the Canary Islands.

It replaces the older Gregory Coudé Telescope and was inaugurated on May 21, 2012.

It is aimed at observing the solar photosphere and chromosphere at visible and infrared wavelengths.

GREGOR sports a high-order adaptive optics (AO) system with a 256-actuator deformable mirrors and a 156-subaperture Shack-Hartmann wavefront sensor.

[6][needs update] Initial astigmatism was fixed during an upgrade with some corrective optics: two off-axis parabolic mirrors.