Placing the GTC primary mirror cell

Animation of the orbits of the six planets around HD110067

Installation and test of the GTC verification camera

GTC acquisition and guidance camera test

Installing the GTC M2 spider

Installing the GTC elevation ring

Leonids in 1999

The Shesat instrument for the alignment of temples in Ancient Egypt

The Shesat sign as a topographical instrument

Astronomical orientation of the pyramids

Light path in Themis telescope

Correction of field rotation in an altazimuthal telescope

Solar wind

Sunspot scale

Solar granulation scale