Apodized Lyot coronagraph for SPHERE/VLT

Carbillet, Marcel; Bendjoya, Philippe; Abe, Lyu; Guerri, Géraldine; Boccaletti, A.; Daban, Jean-Baptiste; Dohlen, Kjetil; Ferrari, A.; Robbe-Dubois, S.; Douet, R.; Vakili, F.

doi:10.1007/s10686-011-9219-4

Cited by 144 publications

(116 citation statements)

References 25 publications

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“…The observations are summarized in Table 2. All the sequences were taken with the same configuration of the apodized Lyot coronagraph (Carbillet et al 2011), which includes a focal plane mask with a diameter of 185 mas and an inner working angle (IWA) of 0. 09.…”

Section: Observationsmentioning

confidence: 99%

First light of the VLT planet finder SPHERE

Zurlo

Vigan

Galicher

et al. 2016

A&A

146

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Context. The planetary system discovered around the young A-type HR 8799 provides a unique laboratory to: a) test planet formation theories; b) probe the diversity of system architectures at these separations, and c) perform comparative (exo)planetology. Aims. We present and exploit new near-infrared images and integral-field spectra of the four gas giants surrounding HR 8799 obtained with SPHERE, the new planet finder instrument at the Very Large Telescope, during the commissioning and science verification phase of the instrument (July-December 2014). With these new data, we contribute to completing the spectral energy distribution (SED) of these bodies in the 1.0-2.5 µm range. We also provide new astrometric data, in particular for planet e, to further constrain the orbits. Methods. We used the infrared dual-band imager and spectrograph (IRDIS) subsystem to obtain pupil-stabilized, dual-band H2H3 (1.593 µm, 1.667 µm), K1K2 (2.110 µm, 2.251 µm), and broadband J (1.245 µm) images of the four planets. IRDIS was operated in parallel with the integral field spectrograph (IFS) of SPHERE to collect low-resolution (R ∼ 30), near-infrared (0.94-1.64 µm) spectra of the two innermost planets HR 8799 d and e. The data were reduced with dedicated algorithms, such as the Karhunen-Loève image projection (KLIP), to reveal the planets. We used the so-called negative planets injection technique to extract their photometry, spectra, and measure their positions. We illustrate the astrometric performance of SPHERE through sample orbital fits compatible with SPHERE and literature data. Results. We demonstrated the ability of SPHERE to detect and characterize planets in this kind of systems, providing spectra and photometry of its components. The spectra improve upon the signal-to-noise ratio of previously obtained data and increase the spectral coverage down to the Y band. In addition, we provide the first detection of planet e in the J band. Astrometric positions for planets HR 8799 bcde are reported for the epochs of July, August, and December 2014. We measured the photometric values in J, H2H3, K1K2 bands for the four planets with a mean accuracy of 0.13 mag. We found upper limit constraints on the mass of a possible planet f of 3-7 M Jup . Our new measurements are more consistent with the two inner planets d and e being in a 2d:1e or 3d:2e resonance. The spectra of HR 8799 d and e are well matched by those of L6-8 field dwarfs. However, the SEDs of these objects are redder than field L dwarfs longward of 1.6 µm.

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Section: Observationsmentioning

confidence: 99%

First light of the VLT planet finder SPHERE

Zurlo

Vigan

Galicher

et al. 2016

A&A

146

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“…First, the fine centering of the star on the coronagraph is performed using an automated procedure that ensures both centering and focusing on the coronagraphic mask. This procedure is used for all coronagraphs available in SPHERE: three apodized Lyot coronagraphs (Carbillet et al 2011) of different dimensions (145, 185, and 240 mas of diameter), two 4-quadrants phase mask coronagraphs (see Boccaletti et al 2008), as well as two classical Lyot coronagraphs. In order to get a precise measurement of the star center behind the coronagraphic mask, a reference image with waffle spots is acquired immediately before or after the scientific sequence.…”

Section: Acquisition Of the Data In Laboratorymentioning

confidence: 99%

Performance of the VLT Planet Finder SPHERE

Zurlo

Vigan

Mesa

et al. 2014

A&A

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Context. The new planet finder for the Very Large Telescope (VLT), the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), just had its first light in Paranal. A dedicated instrument for the direct detection of planets, SPHERE, is composed of a polametric camera in visible light, the Zurich IMager POLarimeter (ZIMPOL), and two near-infrared sub-systems: the Infra-Red Dual-beam Imager and Spectrograph (IRDIS), a multi-purpose camera for imaging, polarimetry, and long-slit spectroscopy, and the integral field spectrograph (IFS), an integral field spectrograph. Aims. We present the results obtained from the analysis of data taken during the laboratory integration and validation phase, after the injection of synthetic planets. Since no continuous field rotation could be performed in the laboratory, this analysis presents results obtained using reduction techniques that do not use the angular differential imaging (ADI) technique. Methods. To perform the simulations, we used the instrumental point spread function (PSF) and model spectra of L and T-type objects scaled in contrast with respect to the host star. We evaluated the expected error in astrometry and photometry as a function of the signal to noise of companions, after spectral differential imaging (SDI) reduction for IRDIS and spectral deconvolution (SD) or principal component analysis (PCA) data reductions for IFS. Results. We deduced from our analysis, for example, that β Picb, a 12 Myr old planet of ∼10 M Jup and semi-major axis of 9-10 AU, would be detected with IRDIS with a photometric error of 0.16 mag and with a relative astrometric position error of 1.1 mas. With IFS, we could retrieve a spectrum with error bars of about 0.15 mag on each channel and astrometric relative position error of 0.6 mas. For a fainter object such as HR 8799d, a 13 M Jup planet at a distance of 27 AU, IRDIS could obtain a relative astrometric error of 3 mas.

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“…5) using a halftone process (Dorrer & Zuegel 2007;Martinez et al 2009;Vigan et al 2016) to reach the required transmission function through the use of an array of microdots (5 µm by 5 µm) with a customized spatial distribution over the 8.1 mm diameter. The same manufacturing process has been used for the SPHERE (Guerri et al 2011;Carbillet et al 2011;Soummer 2005) and GPI (Sivaramakrishnan et al 2010) apodizers. (Fig.…”

Section: Apodizer Characterizationmentioning

confidence: 99%

Laboratory validation of the dual-zone phase mask coronagraph in broadband light at the high-contrast imaging THD testbed

Delorme

N’Diaye

Galicher

et al. 2016

A&A

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Context. Specific high-contrast imaging instruments are mandatory to characterize circumstellar disks and exoplanets around nearby stars. Coronagraphs are commonly used in these facilities to reject the diffracted light of an observed star and enable direct imaging and spectroscopy of its circumstellar environment. One important property of the coronagraph is to be able to work in broadband light. Aims. Among several proposed coronagraphs, the dual-zone phase mask coronagraph is a promising solution for starlight rejection in broadband light. In this paper, we perform the first validation of this concept in laboratory. Methods. First, we consider the principle of the dual-zone phase mask coronagraph. Then, we describe the high-contrast imaging THD testbed, the manufacturing of the components, and the quality control procedures. Finally, we study the sensitivity of our coronagraph to low-order aberrations (inner working angle and defocus) and estimate its contrast performance. Our experimental broadband light results are compared with numerical simulations to check agreement with the performance predictions. Results. With the manufactured prototype and using a dark hole technique based on the self-coherent camera, we obtain contrast levels down to 2 × 10 −8 between 5 and 17 λ 0 /D in monochromatic light (640 nm). We also reach contrast levels of 4 × 10 −8 between 7 and 17 λ 0 /D in broadband (λ 0 = 675 nm, ∆λ = 250 and ∆λ/λ 0 = 40%), which demonstrates the excellent chromatic performance of the dual-zone phase mask coronagraph. Conclusions. The performance reached by the dual-zone phase mask coronagraph is promising for future high-contrast imaging instruments that aim to detect and spectrally characterize old or light gaseous planets.

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Apodized Lyot coronagraph for SPHERE/VLT

Cited by 144 publications

References 25 publications

First light of the VLT planet finder SPHERE

First light of the VLT planet finder SPHERE

Performance of the VLT Planet Finder SPHERE

Laboratory validation of the dual-zone phase mask coronagraph in broadband light at the high-contrast imaging THD testbed

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