Searching for companions down to 2 AU from<i>β</i>Pictoris using the<i>L</i>′-band AGPM coronagraph on VLT/NACO

Absil, Olivier; Milli, J.; Mawet, Dimitri; Lagrange, Anne-Marie; Girard, J.; Chauvin, G.; Boccaletti, A.; Delacroix, Christian; Surdej, Jean

doi:10.1051/0004-6361/201322748

Cited by 80 publications

(113 citation statements)

References 17 publications

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“…1). The probability distributions of other orbital parameters remain consistent with the previous estimations of Chauvin et al (2012) and Absil et al (2013). The probability that β Pic b actually transits along the line of sight is 2%.…”

Section: Orbit and Dynamical Mass Of β Pic Bsupporting

confidence: 88%

“…We combined the GPI relative astrometry of β Pic b (Table 1) with previous NaCo measurements (Chauvin et al 2012;Bonnefoy et al 2013;Absil et al 2013) to refine the orbital solutions of the object based solely on the astrometry. We used the 1 http://www.gemini.edu/sciops/instruments/gpi/ public-data Markov-chain Monte Carlo (MCMC) Bayesian analysis technique described in Chauvin et al (2012) to derive the probablilistic distribution of orbital solutions.…”

Section: Orbit and Dynamical Mass Of β Pic Bmentioning

confidence: 99%

“…The monitoring of the planet's orbital motion restrained the semi-major axis (s.m.a.) estimates to 8−10 AU (Chauvin et al 2012;Absil et al 2013). Combined with radial velocity (RV) measurements , the s.m.a.…”

Section: Introductionmentioning

confidence: 99%

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Physical and orbital properties ofβPictoris b

Bonnefoy

Marleau

Galicher

et al. 2014

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The intermediate-mass star β Pictoris is known to be surrounded by a structured edge-on debris disk within which a gas giant planet was discovered orbiting at 8−10 AU. The physical properties of β Pic b were previously inferred from broad-and narrow-band 0.9−4.8 µm photometry. We used commissioning data of the Gemini Planet Imager (GPI) to obtain new astrometry and a lowresolution (R ∼ 35−39) J-band (1.12−1.35 µm) spectrum of the planet. We find that the planet has passed the quadrature. We constrain its semi-major axis to ≤10 AU (90% prob.) with a peak at 8.9 +0.4 −0.6 AU. The joint fit of the planet astrometry and the most recent radial velocity measurements of the star yields a planet dynamical mass lower than 20 M Jup (≥96% prob.). The extracted spectrum of β Pic b is similar to those of young L1 +1 −1.5 dwarfs. We used the spectral type estimate to revise the planet luminosity to log(L/L ) = −3.90±0.07. The 0.9−4.8 µm photometry and spectrum are reproduced for T eff = 1650 ± 150 K and a log g ≤ 4.7 dex by 12 grids of PHOENIX-based and LESIA atmospheric models. For the most recent system age estimate (21 ± 4 Myr), the bolometric luminosity and the constraints on the dynamical mass of β Pic b are only reproduced by warm-and hot-start tracks with initial entropies S i > 10.5 k B /baryon. These initial conditions may result from an inefficient accretion shock and/or a planetesimal density at formation higher than in the classical core-accretion model. Considering a younger age for the system or a conservative formation time for β Pic b does not change these conclusions.

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Section: Orbit and Dynamical Mass Of β Pic Bsupporting

confidence: 88%

Section: Orbit and Dynamical Mass Of β Pic Bmentioning

confidence: 99%

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Physical and orbital properties ofβPictoris b

Bonnefoy

Marleau

Galicher

et al. 2014

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“…facilities, leading to the detection of exoplanets and circumstellar disks (e.g., Absil et al 2013;Milli et al 2014;Reggiani et al 2014). The off-axis well-corrected subaperture on the Palomar Hale telescope (Serabyn et al 2007) also provides a VC mode, which has led to impressive results (Serabyn et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Post-coronagraphic tip-tilt sensing for vortex phase masks: The QACITS technique

Huby

Baudoz

Mawet

et al. 2015

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Context. Small inner working angle coronagraphs, such as the vortex phase mask, are essential to exploit the full potential of groundbased telescopes in the context of exoplanet detection and characterization. However, the drawback of this attractive feature is a high sensitivity to pointing errors, which degrades the performance of the coronagraph. Aims. We propose a tip-tilt retrieval technique based on the analysis of the final coronagraphic image, hereafter called Quadrant Analysis of Coronagraphic Images for Tip-tilt Sensing (QACITS). Methods. Under the assumption of small phase aberrations, we show that the behavior of the vortex phase mask can be simply described from the entrance pupil to the Lyot stop plane with Zernike polynomials. This convenient formalism is used to establish the theoretical basis of the QACITS technique. We performed simulations to demonstrate the validity and limits of the technique, including the case of a centrally obstructed pupil. Results. The QACITS technique principle is validated with experimental results in the case of an unobstructed circular aperture, as well as simulations in presence of a central obstruction. The typical configuration of the Keck telescope (24% central obstruction) has been simulated with additional high order aberrations. In these conditions, our simulations show that the QACITS technique is still adapted to centrally obstructed pupils and performs tip-tilt retrieval with a precision of 5 × 10 −2 λ/D when wavefront errors amount to λ/14 rms and 10 −2 λ/D for λ/70 rms errors (with λ the wavelength and D the pupil diameter). Conclusions.We have developed and demonstrated a tip-tilt sensing technique for vortex coronagraphs. The implementation of the QACITS technique is based on the analysis of the scientific image and does not require any modification of the original setup. Current facilities equipped with a vortex phase mask can thus directly benefit from this technique to improve the contrast performance close to the axis.

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“…The VC suppresses the light from a star, allowing direct detection of dim companions, exoplanets, and circumstellar disks. Imaging objects with a VC, which are otherwise buried in the noise associated with the bright host star, has been demonstrated in laboratory (e.g., Mawet et al 2009;Delacroix et al 2013) and on-sky observations (e.g., Swartzlander et al 2008;Mawet et al 2010;Serabyn et al 2010;Absil et al 2013;Defrère et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Lyot-plane phase masks for improved high-contrast imaging with a vortex coronagraph

Ruane

Huby

Absil

et al. 2015

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Context. The vortex coronagraph is an optical instrument that precisely removes on-axis starlight allowing for high contrast imaging at small angular separation from the star, a crucial capability for direct detection and characterization of exoplanets and circumstellar disks. Telescopes with aperture obstructions, such as secondary mirrors and spider support structures, require advanced coronagraph designs to provide adequate starlight suppression. Aims. We introduce a phase-only Lyot-plane optic to the vortex coronagraph, which offers improved contrast performance on telescopes with complicated apertures. Potential solutions for the European Extremely Large Telescope (E-ELT) are described. Methods. Adding a Lyot-plane phase mask relocates residual starlight away from a region of the image plane, thereby reducing stellar noise and improving sensitivity to off-axis companions. The phase mask is calculated using an iterative phase retrieval algorithm. Results. Numerically, we achieve a contrast on the order of 10 −6 for a companion with angular displacement as small as 4λ/D with an E-ELT type aperture. Even in the presence of aberrations, improved performance is expected compared to either a conventional vortex coronagraph or an optimized pupil plane phase element alone.

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Searching for companions down to 2 AU fromβPictoris using theL′-band AGPM coronagraph on VLT/NACO

Cited by 80 publications

References 17 publications

Physical and orbital properties ofβPictoris b

Physical and orbital properties ofβPictoris b

Post-coronagraphic tip-tilt sensing for vortex phase masks: The QACITS technique

Lyot-plane phase masks for improved high-contrast imaging with a vortex coronagraph

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