First Light for the GRAVITY+ Adaptive Optics: Extreme Adaptive Optics for the Very Large Telescope Interferometer

Abstract

GRAVITY+ improves by orders of magnitude the sensitivity, sky-coverage and contrast of the Very Large Telescope Interferometer (VLTI). A central part of this project is the development of Gravity Plus Adaptive Optics (GPAO), a dedicated high-order and laser-guide star Adaptive Optics (AO) system for VLTI. GPAO consists of four state-of-the-art AO systems equipping all 8m-class Unit Telescopes (UTs) for the wavefront correction of the VLTI instruments. It offers both visible and infrared Natural Guide Star (NGS) and Laser Guide Star (LGS) operations. The paper presents the design, operations and performances of GPAO. We illustrate the improvement brought by GPAO with interferometric observations obtained during the commissioning of the NGS mode end-2024. These science results include the first optical interferometry observations of a redshift $z\sim 4$ quasar, the spectroscopy of a cool brown-dwarf with magnitude $K\sim 21.0$, the first observations of a Class I young star with GRAVITY, and the first sub-micro arcsecond differential astrometry in the optical. Together with the entire GRAVITY+ project, the implementation of GPAO is a true paradigm shift for observing the optical Universe at very high angular resolution.

Accepted in A&A

References in corpus (39)

• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole
• A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty
• Gaia Early Data Release 3: Photometric content and validation
• First Light for GRAVITY: Phase Referencing Optical Interferometry for the Very Large Telescope Interferometer
• The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit
• SPHERE: the exoplanet imager for the Very Large Telescope
• Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole
• Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA*
• JADES. The diverse population of infant Black Holes at 4<z<11: merging, tiny, poor, but mighty
• PIONIER: a 4-telescope visitor instrument at VLTI
• The mass distribution in the Galactic Centre from interferometric astrometry of multiple stellar orbits
• Spatially resolved rotation of the broad-line region of a quasar at sub-parsec scale
• Structure of Herbig AeBe disks at the milliarcsecond scale A statistical survey in the H band using PIONIER-VLTI
• First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e
• Peering into the formation history of beta Pictoris b with VLTI/GRAVITY long baseline interferometry
• Direct confirmation of the radial-velocity planet $\beta$ Pic c
• beta Pic b position relative to the Debris Disk
• The spin-orbit alignment of the Fomalhaut planetary system probed by optical long baseline interferometry
• The mass of Beta Pictoris c from Beta Pictoris b orbital motion
• The GRAVITY Young Stellar Object survey -- I. Probing the disks of Herbig Ae/Be stars in terrestrial orbits
• A dynamical measure of the black hole mass in a quasar 11 billion years ago
• First Resolution of Microlensed Images
• Direct imaging of an ultracool substellar companion to the exoplanet host star HD 4113A
• A measure of the size of the magnetospheric accretion region in TW Hydrae
• The Enhanced Resolution Imager and Spectrograph for the VLT
• The GRAVITY Young Stellar Object survey. VII. The inner dusty disks of T Tauri stars
• First Light for GRAVITY Wide: Large Separation Fringe Tracking for the Very Large Telescope Interferometer
• NAOMI: the adaptive optics system of the Auxiliary Telescopes of the VLTI
• Spin-orbit alignment of the $\beta$ Pictoris planetary system
• The cool brown dwarf Gliese 229 B is a close binary
• The accretion of a solar mass per day by a 17-billion solar mass black hole
• SPRINT: System Parameters Recurrent INvasive Tracking, a fast and least-cost online calibration strategy for adaptive optics
• Estimating the phase in ground-based interferometry: performance comparison between single-mode and multimode schemes
• A catalogue of dual-field interferometric binary calibrators
• GRAVITY for MATISSE -- Improving the MATISSE performance with the GRAVITY fringe tracker
• Estimation of the lateral mis-registrations of the GRAVITY + adaptive optics system
• The GRAVITY young stellar object survey XIV : Investigating the magnetospheric accretion-ejection processes in S CrA N
• Exoplanets in reflected starlight with dual-field interferometry: A case for shorter wavelengths and a fifth Unit Telescope at VLTI/Paranal

Cited by in corpus (3)

• The ExoGRAVITY survey: A K-band spectral library of giant exoplanet and brown dwarf companions
• Unveiling the properties of galaxy cores excavated by supermassive black hole binaries with SHARP
• VLTI-GRAVITY observations of blazars