Towards on-sky adaptive optics control using reinforcement learning

no code implementations • 16 May 2022 • J. Nousiainen, C. Rajani, M. Kasper, T. Helin, S. Y. Haffert, C. Vérinaud, J. R. Males, K. Van Gorkom, L. M. Close, J. D. Long, A. D. Hedglen, O. Guyon, L. Schatz, M. Kautz, J. Lumbres, A. Rodack, J. M. Knight, K. Miller

PO4AO provides the desired performance by improving the coronagraphic contrast in numerical simulations by factors 3-5 within the control region of DM and Pyramid WFS, in simulation and in the laboratory.

reinforcement-learning Reinforcement Learning (RL)

A High-Contrast Search for Variability in HR 8799bc with VLT-SPHERE

no code implementations • 21 Jan 2021 • B. A. Biller, D. Apai, M. Bonnefoy, S. Desidera, R. Gratton, M. Kasper, M. Kenworthy, A. M. Lagrange, C. Lazzoni, D. Mesa, A. Vigan, K. Wagner, J. M. Vos, A. Zurlo

To quantify our sensitivity to variability, we simulate variable lightcurves by inserting and retrieving a suite of simulated planets at similar radii from the star as HR 8799bc, but offset in position angle.

Earth and Planetary Astrophysics Instrumentation and Methods for Astrophysics

Mid-infrared photometry of the T Tauri triple system with kernel phase interferometry

no code implementations • 21 Dec 2020 • J. Kammerer, M. Kasper, M. J. Ireland, R. Köhler, R. Laugier, F. Martinache, R. Siebenmorgen, M. E. van den Ancker, R. van Boekel, T. M. Herbst, E. Pantin, H. -U. Käufl, D. J. M. Petit dit de la Roche, V. D. Ivanov

We aim to measure the brightness of all three components of the T Tauri system (T Tau N, T Tau Sa, T Tau Sb) in the mid-infrared in order to obtain photometry around the $\sim 9. 7~\mu m$ silicate feature.

Solar and Stellar Astrophysics

Design, pointing control, and on-sky performance of the mid-infrared vortex coronagraph for the VLT/NEAR experiment

no code implementations • 15 Dec 2020 • A. -L. Maire, E. Huby, O. Absil, G. Zins, M. Kasper, C. Delacroix, S. Leveratto, M. Karlsson, G. Ruane, H. -U. Käufl, G. Orban de Xivry, P. Pathak, L. Pettazzi, P. Duhoux, J. Kolb, E. Pantin, A. J. Eldorado Riggs, R. Siebenmorgen, D. Mawet

Here, we present the design of the mid-IR vortex coronagraph for the new Earths in the $\alpha$ Cen Region (NEAR) experiment with the VLT/VISIR instrument and assess the performance of the QACITS estimator for the centering control of the star image onto the vortex coronagraph.

Instrumentation and Methods for Astrophysics

Investigating three Sirius-like systems with SPHERE

no code implementations • 10 Dec 2020 • R. Gratton, V. D'Orazi, T. A. Pacheco, A. Zurlo, S. Desidera, J. Melendez, D. Mesa, R. Claudi, M. Janson, M. Langlois, E. Rickman, M. Samland, T. Moulin, C. Soenke, E. Cascone, J. Ramos, F. Rigal, H. Avenhaus, J. L. Beuzit, B. Biller, A. Boccaletti, M. Bonavita, M. Bonnefoy, W. Brandner, G. Chauvin, M. Cudel, S. Daemgen, P. Delorme, C. Desgrange, N. Engler, M. Feldt, C. Fontanive, R. Galicher, A. Garufi, D. Gasparri, C. Ginski, J. Girard, J. Hagelberg, S. Hunziker, M. Kasper, M. Keppler, A. -M. Lagrange, J. Lannier, C. Lazzoni, H. Le Coroller, R. Ligi, M. Lombart, A. -L. Maire, M. R. Mayer, S. Mazevet, F. Menard, D. Mouillet, C. Perrot, S. Peretti, S. Petrus, A. Potier, D. Rouan, H. M. Schmid, T. O. B. Schmidt, E. Sissa, T. Stolker, G. Salter, A. Vigan, F. Wildi

The composition of the MS stars agrees fairly well with expectations from pollution by the AGB progenitors of the WDs: HD2133A has a small enrichment of n-capture elements, which is as expected for pollution by an AGB star with a mass <1. 5 Mo; CD-56 7708A is a previously unrecognized mild Ba-star, which is expected due to pollution by an AGB star with a mass in the range of 1. 5-3. 0 Mo; and HD114174 has a very moderate excess of n-capture elements, which is in agreement with the expectation for a massive AGB star to have a mass >3. 0 Mo.

Solar and Stellar Astrophysics

Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES+

no code implementations • 3 Sep 2020 • G. P. P. L. Otten, A. Vigan, E. Muslimov, M. N'Diaye, E. Choquet, U. Seemann, K. Dohlen, M. Houllé, P. Cristofari, M. W. Phillips, Y. Charles, I. Baraffe, J. -L. Beuzit, A. Costille, R. Dorn, M. El Morsy, M. Kasper, M. Lopez, C. Mordasini, R. Pourcelot, A. Reiners, J. -F. Sauvage

We study the performance of the proposed HiRISE fiber coupling between the SPHERE and CRIRES+ at the VLT for spectral characterization of directly imaged planets.

Instrumentation and Methods for Astrophysics Earth and Planetary Astrophysics