Current results of the PERSEE testbench: the cophasing control and the polychromatic null rate

Stabilizing a nulling interferometer at a nanometric level is the key issue to obtain deep null depths. The PERSEE breadboard has been designed to study and optimize the operation of a cophased nulling bench in the most realistic disturbing environment of a space mission. This presentation focuses on the current results of the PERSEE bench. In terms of metrology, we cophased at 0.33 nm rms for the piston and 80 mas rms for the tip/tilt (0.14% of the Airy disk). A Linear Quadratic Gaussian (LQG) control coupled with an unsupervised vibration identification allows us to maintain that level of correction, even with characteristic vibrations of nulling interferometry space missions. These performances, with an accurate design and alignment of the bench, currently lead to a polychromatic unpolarised null depth of 8.9E-6 stabilized at 3E-7 on the [1.65-2.45] \mum spectral band (37% bandwidth).Comment: 17 pages, 10 figures, proceedings of the Optics+Photonics SPIE conference, San Diego, 201

The GRAVITY+ Project: Towards All-sky, Faint-Science, High-Contrast Near-Infrared Interferometry at the VLTI

The GRAVITY instrument has been revolutionary for near-infrared interferometry by pushing sensitivity and precision to previously unknown limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) in GRAVITY+, these limits will be pushed even further, with vastly improved sky coverage, as well as faint-science and high-contrast capabilities. This upgrade includes the implementation of wide-field off-axis fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser guide stars in an upgraded facility. GRAVITY+ will open up the sky to the measurement of black hole masses across cosmic time in hundreds of active galactic nuclei, use the faint stars in the Galactic centre to probe General Relativity, and enable the characterisation of dozens of young exoplanets to study their formation, bearing the promise of another scientific revolution to come at the VLTI.Comment: Published in the ESO Messenge

System analysis of the Segmented Pupil Experiment for Exoplanet Detection - SPEED - in view of the ELTs

SPEED is a new experiment in progress at the Lagrange laboratory to study some critical aspects to succeed invery deep high-contrast imaging at close angular separations with the next generation of ELTs. The SPEEDbench will investigate optical, system, and algorithmic approaches to minimize the ELT primary mirrordiscontinuities and achieve the required contrast for targeting low mass exoplanets. The SPEED projectcombines high precision co-phasing architectures, wavefront control and shaping using two sequential high orderdeformable mirrors, and advanced coronagraphy (PIAACMC). In this paper, we describe the overall systemarchitecture and discuss some characteristics to reach 10-7 contrast at roughly 1λ/D

System analysis of the Segmented Pupil Experiment for Exoplanet Detection - SPEED - in view of the ELTs

SPEED is a new experiment in progress at the Lagrange laboratory to study some critical aspects to succeed invery deep high-contrast imaging at close angular separations with the next generation of ELTs. The SPEEDbench will investigate optical, system, and algorithmic approaches to minimize the ELT primary mirrordiscontinuities and achieve the required contrast for targeting low mass exoplanets. The SPEED projectcombines high precision co-phasing architectures, wavefront control and shaping using two sequential high orderdeformable mirrors, and advanced coronagraphy (PIAACMC). In this paper, we describe the overall systemarchitecture and discuss some characteristics to reach 10-7 contrast at roughly 1λ/D

The segmented pupil experiment for exoplanet detection: Part 3. Advances and first light with segments cophasing

International audienceSPEED (Segmented Pupil Experiment for Exoplanet Detection) is an instrumental testbed designed to offer an ideal cocoon to provide relevant solutions in both cophasing and high-contrast imaging with segmented telescopes. The next generation of observatories will be made of a primary mirror with excessive complexity (mirror segmentation, central obscuration, and spider vanes) undoubtedly known to be unfavorable for the direct detection of exoplanets. Exoplanets detection around late-type stars (M-dwarfs) constitutes an outstanding reservoir of candidates, and SPEED integrates all the recipes to pave the road for this science case (cophasing sensors, multi-DM wavefront control and shaping architecture as well as advanced coronagraphy). In this paper, we provide a progress overview of the project and report on the first light with segments cophasing control and monitoring from a coronagraphic image

The binary Be star δ Sco at high spectral and spatial resolution: Disk geometry and kinematics before the 2011 periastron

A&A accepted paperClassical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed IR-excess and emission lines. The influence of binarity on these phenomena remains controversial. delta Sco is a binary system whose primary suddently began to exhibit the Be phenomenon at the last periastron in 2000. We want to constrain the geometry and kinematics of its circumstellar environment. We observed the star between 2007 and 2010 using spectrally-resolved interferometry with the VLTI/AMBER and CHARA/VEGA instruments. We found orbital elements that are compatible with previous estimates. The next periastron should take place around July 5, 2011 (+- 4,days). We resolved the circumstellar disk in the HAlpha (FWHM = 4.8+-1.5mas), BrGamma (FWHM = 2.9 0.,mas), and the 2.06$\mu$m HeI (FWHM = 2.4+-0.3mas) lines as well as in the K band continuum (FWHM ~2.4mas). The disk kinematics are dominated by the rotation, with a disk expansion velocity on the order of 0.2km/s. The rotation law within the disk is compatible with Keplerian rotation. As the star probably rotates at about 70% of its critical velocity the ejection of matter doesn't seems to be dominated by rotation. However, the disk geometry and kinematics are similar to that of the previously studied quasi-critically rotating Be stars, namely Alpha Ara, Psi Per and 48 Per

The Nice Cube (Nice3^3) nanosatellite project

International audienceCubeSats are tiny satellites with increasing capabilities. They have been used for more than a decade by universities to train students on space technologies, in a hands-on project aiming at building, launching and operating a real satellite. Still today, one shortcoming of CubeSats is their poor ability to transmit large amounts of data to the ground. A possible way to overcome this limitation relies on optical communications. Université Côte d'Azur is studying the feasibility of a student's CubeSat whose main goal is to transmit data with an optical link to the ground at the moderate rate of 1 kb/s (or better). In this paper, we will present the current state of the project and its future developments

MATISSE: Performance in laboratory, results of AIV in Paranal, and first results on sky

International audienc