Tightly connect tubes used for the circulation of cryogenic fluids is a task that requires some thought and technical experience. ESO is intensively using liquid nitrogen either to pre-cool large infrared instruments or to keep most of the optical and some IR detectors at cryogenic operating temperature. A solid experience has been gained with many

Commissioning results, on-sky performance and first operations of the Javalambre Panoramic Camera (JPCam) are presented in this paper. JPCam is a 1.2 Gpixel camera deployed on the 2.6m, large field-of-vie Javalambre Survey Telescope (JST250) at the Observatorio Astrofísico Javalambre. JPCam has been conceived to perform J-PAS, a photometric survey

The effects of atmospheric dispersion on the performance of astronomical Adaptive Optics (AO) were already described in the 70's, and they are generally regarded irrelevant to nighttime AO, except for the very specific case of Extreme AO for the next generation of 30 and 40-m class large ground-based telescopes. However, the situation changes when

Being the NRT 1 an international collaboration to design and build a leading astronomical facility, it will be focused in the optical and near infrared ranges for the emergent area of time domain astronomy. This will rely on the mix of a large collecting area (4 m diameter), quick response (<30 s), and full robotic operation. The Telescope Level

This conference presentation was prepared for the Ground-based and Airborne Telescopes IX conference at SPIE Astronomical Telescopes + Instrumentation, 2022.

WEAVE is the new wide-field spectroscopy facility 1,2,3 for the prime focus of the William Herschel Telescope in La Palma, Spain. Its fibre positioner is essential for the accurate placement of the spectrograph's 960 fibre multiplex. We provide an overview of the recent maintenance, flexure modifications, and calibration measurements conducted at