475 citations · 1.2k across the 111 of their papers we have counts for
9 papers · 1 filter
Using the generalised-optical differentiation wavefront sensor for laser guide star wavefront sensing
Sebastiaan Y. Haffert, Christoph U. Keller, Richard Dekany
Laser guide stars (LGS) are used in many adaptive optics systems to extend sky coverage. The most common wavefront sensor used in combination with a LGS is a Shack-Hartmann wavefro…
Self-optimizing adaptive optics control with Reinforcement Learning
Rico Landman, Sebastiaan Y. Haffert, Vikram M. Radhakrishnan +1
Current and future high-contrast imaging instruments require extreme Adaptive Optics (XAO) systems to reach contrasts necessary to directly image exoplanets. Telescope vibrations a…
Searching for proto-planets with MUSE
C. Xie, S. Y. Haffert, J. de Boer +5
Protoplanetary disks contain structures such as gaps, rings, and spirals, which are thought to be produced by the interaction between the disk and embedded protoplanets. However, o…
Betelgeuse scope: Single-mode-fibers-assisted optical interferometer design for dedicated stellar activity monitoring
Narsireddy Anugu, Katie M. Morzinski, Josh Eisner +12
Betelgeuse has gone through a sudden shift in its brightness and dimmed mysteriously. This is likely caused by a hot blob of plasma ejected from Betelgeuse and then cooled to obscu…
Diffraction-limited integral-field spectroscopy for extreme adaptive optics systems with the Multi-Core fiber-fed Integral-Field Unit
Sebastiaan Y. Haffert, Robert J. Harris, Alessio Zanutta +31
Direct imaging instruments have the spatial resolution to resolve exoplanets from their host star. This enables direct characterization of the exoplanets atmosphere, but most direc…
CS Cha B: A disc-obscured M-type star mimicking a polarised planetary companion
S. Y. Haffert, R. G. van Holstein, C. Ginski +6
Context. Direct imaging provides a steady flow of newly discovered giant planets and brown dwarf companions. These multi-object systems can provide information about the formation…
Nonlinear wavefront reconstruction with convolutional neural networks for Fourier-based wavefront sensors
Rico Landman, Sebastiaan Haffert
Fourier-based wavefront sensors, such as the Pyramid Wavefront Sensor (PWFS), are the current preference for high contrast imaging due to their high sensitivity. However, these wav…
SPHERE+: Imaging young Jupiters down to the snowline
A. Boccaletti, G. Chauvin, D. Mouillet +130
SPHERE (Beuzit et al,. 2019) has now been in operation at the VLT for more than 5 years, demonstrating a high level of performance. SPHERE has produced outstanding results using a…
Original use of MUSE's laser tomography adaptive optics to directly image young accreting exoplanets
Julien H. Girard, Jozua de Boer, Sebastiaan Haffert +8
We present recent results obtained with the VLT/MUSE Integral Field Spectrograph fed by the 4LGSF and its laser tomography adaptive optics module GALACSI. While this so-called narr…