WEAVE is the new wide-field spectroscopic facility 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. To maximise the assignment of its optical fibres, WEAVE uses a simulated annealing algorithm called Configure, 1 which

This paper introduces a new technique for performing binary adaptive optics using optical components only, without the help of any electronic, or optoelectronic device. In this technique, the interferogram produced by the interference of a reference plane wave and the distorted wave modulates a light-driven crystal. The modulated light-driven

The Mirror-slicer Array for Astronomical Transients (MAAT) is a new IFU for the OSIRIS spectrograph on the 10.4-m Gran Telescopio CANARIAS (GTC) at La Palma, spectrograph that has been recently upgraded with a new detector and moved to the Cassegrain focus. Funding has been secured to build MAAT. We present the nearly final design, its expected

THEMIS, a 90 cm solar telescope, offers spectropolarimetric observations in the VIS and NIR spectral ranges through a long-slit spectrograph. Now, an image slicer-based Integral Field Unit (IFU) is being developed as an evolution of the long-slit set-up. The IFU will allow observing a 2D Field-of-View (FoV) and several spectral regions

The GREGOR Infrared Spectrograph (GRIS) can perform spectropolarimetric observations in 1.0-1.8 μm and pure spectroscopic in the band 2.0-2.3 μm. The spectrograph has a Czerny-Turner design and has allowed the operation in the traditional long-slit mode since 2014. And also, in IFU mode since was upgraded in 2018. A third upgrade took place in 2021

We report the discovery and analysis of a planet in the microlensing event OGLE-2018-BLG-0799. The planetary signal was observed by several ground-based telescopes, and the planet-host mass ratio is q = (2.65 ± 0.16) × 10 -3. The ground-based observations yield a constraint on the angular Einstein radius θ E, and the microlensing parallax vector $