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1. Dynamical and Atmospheric Characterization of the Substellar Companion HD 33632 Ab from Direct Imaging, Astrometry, and Radial-velocity Data

Author

Mona El Morsy, Thayne Currie, Danielle Bovie, Masayuki Kuzuhara, Brianna Lacy, Yiting Li, Taylor Tobin, Timothy D. Brandt, Jeffrey Chilcote, Olivier Guyon, Tyler D. Groff, Julien Lozi, Sebastien Vievard, Vincent Deo, Nour Skaf, Francois Bouchy, Isabelle Boisse, Erica Dykes, N. Jeremy Kasdin, and Motohide Tamura

Subjects
Adaptive optics, Brown dwarfs, Exoplanets, Direct imaging, Astrophysics, QB460-466
Abstract

We present follow-up SCExAO/CHARIS H- and K -band ( R ∼ 70) high-contrast integral field spectroscopy and Keck/NIRC2 photometry of directly imaged brown dwarf companion HD 33632 Ab and new radial-velocity data for the system from the SOPHIE spectrograph, complemented by Hipparcos and Gaia astrometry. These data enable more robust spectral characterization compared to lower-resolution spectra from the discovery paper and more than double the available astrometric and radial-velocity baseline. HD 33632 Ab’s spectrum is well reproduced by a field L8.5–L9.5 dwarf. Using the Exo-REM atmosphere models, we derive a best-fit temperature, surface gravity, and radius of T _eff = 1250 K, log( g ) = 5, and R = 0.97 R _J , respectively, as well as a solar C/O ratio. Adding the SOPHIE radial-velocity data enables far tighter constraints on the companion’s orbital properties (e.g., i = ${47.5}_{-4.7}^{+2.5}$ ^o ) and dynamical mass ( ${52.8}_{-2.4}^{+2.6}$ M _J ) than derived from imaging data and Gaia eDR3 astrometry data alone. HD 33632 Ab should be a prime target for multiband imaging and spectroscopy with the James Webb Space Telescope and the Roman Space Telescope’s Coronagraphic Instrument, shedding detailed light on HD 33632 Ab’s clouds and chemistry and providing a key reference point for understanding young exoplanet atmospheres.

Published
2025
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2. SCExAO/CHARIS Near-infrared Scattered-light Imaging and Integral Field Spectropolarimetry of the AB Aurigae Protoplanetary System

Author

Erica Dykes, Thayne Currie, Kellen Lawson, Miles Lucas, Tomoyuki Kudo, Minghan Chen, Olivier Guyon, Tyler D. Groff, Julien Lozi, Jeffrey Chilcote, Timothy D. Brandt, Sebastien Vievard, Nour Skaf, Vincent Deo, Mona El Morsy, Danielle Bovie, Taichi Uyama, Carol Grady, Michael Sitko, Jun Hashimoto, Frantz Martinache, Nemanja Jovanovic, Motohide Tamura, and N. Jeremy Kasdin

Subjects
Protoplanetary disks, Adaptive optics, Exoplanet formation, Astrophysics, QB460-466
Abstract

We analyze near-infrared integral field spectropolarimetry of the AB Aurigae protoplanetary disk and protoplanet (AB Aur b), obtained with SCExAO/CHARIS in 22 wavelength channels covering the J , H , and K passbands ( λ _0 = 1.1–2.4 μ m) over angular separations of ρ ≈ 0.″13 to 1.″1 (∼20–175 au). Our images resolve spiral structures in the disk in each CHARIS channel. At the longest wavelengths, the data may reveal an extension of the western spiral seen in previous polarimetric data at ρ < 0.″3 out to larger distances clockwise from the protoplanet AB Aur b, coincident with the Atacama Large Millimeter/submillimeter Array–detected CO gas spiral. While AB Aur b is detectable in complementary total intensity data, it is a nondetection in polarized light at λ > 1.3 μ m. While the observed disk color is extremely red across JHK , the disk has a blue intrinsic scattering color consistent with small dust grains. The disk’s polarization spectrum is redder than AB Aur b’s total intensity spectrum. The polarization fraction peaks at ∼0.6 along the major disk axis. Radiative transfer modeling of the CHARIS data shows that small, porous dust grains with a porosity of p = 0.6–0.8 better reproduce the scattered-light appearance of the disk than more compact spheres ( p = 0.3), especially the polarization fraction. This work demonstrates the utility of integral field spectropolarimetry to characterize structures in protoplanetary disks and elucidate the properties of the disks’ dust.

Published
2024
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3. Direct-imaging Discovery of a Substellar Companion Orbiting the Accelerating Variable Star HIP 39017

Author

Taylor L. Tobin, Thayne Currie, Yiting Li, Jeffrey Chilcote, Timothy D. Brandt, Brianna Lacy, Masayuki Kuzuhara, Maria Vincent, Mona El Morsy, Vincent Deo, Jonathan P. Williams, Olivier Guyon, Julien Lozi, Sebastien Vievard, Nour Skaf, Kyohoon Ahn, Tyler Groff, N. Jeremy Kasdin, Taichi Uyama, Motohide Tamura, Aidan Gibbs, Briley L. Lewis, Rachel Bowens-Rubin, Maïssa Salama, Qier An, and Minghan Chen

Subjects
Direct imaging, Brown dwarfs, Astrometry, Coronagraphic imaging, Astronomy, QB1-991
Abstract

We present the direct-imaging discovery of a substellar companion (a massive planet or low-mass brown dwarf) to the young, γ Doradus ( γ Dor)-type variable star HIP 39017 (HD 65526). The companion’s SCExAO/CHARIS JHK (1.1–2.4 μ m) spectrum and Keck/NIRC2 $L^{\prime} $ photometry indicate that it is an L/T transition object. A comparison of the JHK + L $^{\prime} $ spectrum to several atmospheric model grids finds a significantly better fit to cloudy models than cloudless models. Orbit modeling with relative astrometry and precision stellar astrometry from Hipparcos and Gaia yields a semimajor axis of ${23.8}_{-6.1}^{+8.7}$ au, a dynamical companion mass of ${30}_{-12}^{+31}$ M _J , and a mass ratio of ∼1.9%, properties most consistent with low-mass brown dwarfs. However, its mass estimated from luminosity models is a lower ∼13.8 M _J due to an estimated young age (≲115 Myr); using a weighted posterior distribution informed by conservative mass constraints from luminosity evolutionary models yields a lower dynamical mass of ${23.6}_{-7.4}^{+9.1}$ M _J and a mass ratio of ∼1.4%. Analysis of the host star’s multifrequency γ Dor-type pulsations, astrometric monitoring of HIP 39017 b, and Gaia Data Release 4 astrometry of the star will clarify the system age and better constrain the mass and orbit of the companion. This discovery further reinforces the improved efficiency of targeted direct-imaging campaigns informed by long-baseline, precision stellar astrometry.

Published
2024
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4. Characterizing a World Within the Hot-Neptune Desert: Transit Observations of LTT 9779 b with the Hubble Space Telescope/WFC3

Author

Billy Edwards, Quentin Changeat, Angelos Tsiaras, Andrew Allan, Patrick Behr, Simone R. Hagey, Michael D. Himes, Sushuang Ma, Keivan G. Stassun, Luis Thomas, Alexandra Thompson, Aaron Boley, Luke Booth, Jeroen Bouwman, Kevin France, Nataliea Lowson, Annabella Meech, Caprice L. Phillips, Aline A. Vidotto, Kai Hou Yip, Michelle Bieger, Amélie Gressier, Estelle Janin, Ing-Guey Jiang, Pietro Leonardi, Subhajit Sarkar, Nour Skaf, Jake Taylor, Ming Yang, and Derek Ward-Thompson

Subjects
Exoplanets, Hot Neptunes, Infrared spectroscopy, Hubble Space Telescope, Astronomy, QB1-991
Abstract

We present an atmospheric analysis of LTT 9779 b, a rare planet situated in the hot-Neptune desert, that has been observed with Hubble Space Telescope (HST)/WFC3 with G102 and G141. The combined transmission spectrum, which covers 0.8–1.6 μ m, shows a gradual increase in transit depth with wavelength. Our preferred atmospheric model shows evidence for H _2 O, CO _2 , and FeH with a significance of 3.1 σ , 2.4 σ , and 2.1 σ , respectively. In an attempt to constrain the rate of atmospheric escape for this planet, we search for the 1.083 μ m helium line in the G102 data but find no evidence of excess absorption that would indicate an escaping atmosphere using this tracer. We refine the orbital ephemerides of LTT 9779 b using our HST data and observations from TESS, searching for evidence of orbital decay or apsidal precession, which are not found. The phase-curve observation of LTT 9779 b with JWST NIRISS should provide deeper insights into the atmosphere of this planet and the expected atmospheric escape might be detected with further observations concentrated on other tracers such as Ly α .

Published
2023
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5. Exploring the Ability of Hubble Space Telescope WFC3 G141 to Uncover Trends in Populations of Exoplanet Atmospheres through a Homogeneous Transmission Survey of 70 Gaseous Planets

Author

Billy Edwards, Quentin Changeat, Angelos Tsiaras, Kai Hou Yip, Ahmed F. Al-Refaie, Lara Anisman, Michelle F. Bieger, Amélie Gressier, Sho Shibata, Nour Skaf, Jeroen Bouwman, James Y-K. Cho, Masahiro Ikoma, Olivia Venot, Ingo Waldmann, Pierre-Olivier Lagage, and Giovanna Tinetti

Subjects
Exoplanet atmospheres, Exoplanet atmospheric composition, Bayesian statistics, Surveys, Hubble Space Telescope, Astronomy data reduction, Astrophysics, QB460-466
Abstract

We present analysis of the atmospheres of 70 gaseous extrasolar planets via transit spectroscopy with Hubble’s Wide Field Camera 3 (WFC3). For over half of these, we statistically detect spectral modulation that our retrievals attribute to molecular species. Among these, we use Bayesian hierarchical modeling to search for chemical trends with bulk parameters. We use the extracted water abundance to infer the atmospheric metallicity and compare it to the planet’s mass. We also run chemical equilibrium retrievals, fitting for the atmospheric metallicity directly. However, although previous studies have found evidence of a mass–metallicity trend, we find no such relation within our data. For the hotter planets within our sample, we find evidence for thermal dissociation of dihydrogen and water via the H ^− opacity. We suggest that the general lack of trends seen across this population study could be due to (i) the insufficient spectral coverage offered by the Hubble Space Telescope’s WFC3 G141 band, (ii) the lack of a simple trend across the whole population, (iii) the essentially random nature of the target selection for this study, or (iv) a combination of all the above. We set out how we can learn from this vast data set going forward in an attempt to ensure comparative planetology can be undertaken in the future with facilities such as the JWST, Twinkle, and Ariel. We conclude that a wider simultaneous spectral coverage is required as well as a more structured approach to target selection.

Published
2023
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6. Direct-imaging Discovery and Dynamical Mass of a Substellar Companion Orbiting an Accelerating Hyades Sun-like Star with SCExAO/CHARIS

Author

Masayuki Kuzuhara, Thayne Currie, Takuya Takarada, Timothy D. Brandt, Bun’ei Sato, Taichi Uyama, Markus Janson, Jeffrey Chilcote, Taylor Tobin, Kellen Lawson, Yasunori Hori, Olivier Guyon, Tyler D Groff, Michael W McElwain, Tyler D. Groff, Julien Lozi, Sebastien Vievard, Ananya Sahoo, Vincent Deo, Nemanja Jovanovic, Kyohoon Ahn, Frantz Martinache, Nour Skaf, Eiji Akiyama, Barnaby R Norris, Mickaël Bonnefoy, Krzysztof G Hełminiak, Tomoyuki Kudo, Matthias Samland, Kevin R Wagner, John Wisniewski, Gillian R Knapp, Jungmi Kwon, Jun Nishikawa, Eugene Serabyn, Masahiko Hayashi, and Motohide Tamura

Abstract

We present the direct-imaging discovery of a substellar companion in orbit around a Sun-like star member of the Hyades open cluster. So far, no other substellar companions have been unambiguously confirmed via direct imaging around main-sequence stars in Hyades. The star HIP 21152 is an accelerating star as identified by the astrometry from the Gaia and Hipparcos satellites. We detected the companion, HIP 21152 B, in multiple epochs using the high-contrast imaging from SCExAO/CHARIS and Keck/NIRC2. We also obtained the stellar radialvelocity data from the Okayama 188 cm telescope. The CHARIS spectroscopy reveals that HIP 21152 B’s spectrum is consistent with the L/T transition, best fit by an early T dwarf. Our orbit modeling determines the semimajor axis and the dynamical mass of HIP 21152 B to be 17 +7.2−3.8 and 27.8 +8.4−5.4 MJub, respectively. The mass ratio of HIP 21152 B relative to its host is ≈2%, near the planet/brown dwarf boundary suggested by recent surveys. Mass estimates inferred from luminosity-evolution models are slightly higher (33–42 MJup). With a dynamical mass and a well-constrained age due to the system’s Hyades membership, HIP 21152 B will become a critical benchmark in understanding the formation, evolution, and atmosphere of a substellar object as a function of mass and age. Our discovery is yet another key proof of concept for using precision astrometry to select direct-imaging targets.

Published
2022
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8. SCExAO and Keck Direct Imaging Discovery of a Low-mass Companion Around the Accelerating F5 Star HIP 5319*

Author

Noah Swimmer, Thayne Currie, Sarah Steiger, G. Mirek Brandt, Timothy D. Brandt, Olivier Guyon, Masayuki Kuzuhara, Jeffrey Chilcote, Taylor Tobin, Tyler D. Groff, Julien Lozi, John I. III Bailey, Alexander B. Walter, Neelay Fruitwala, Nicholas Zobrist, Jennifer Pearl Smith, Gregoire Coiffard, Rupert Dodkins, Kristina K. Davis, Miguel Daal, Bruce Bumble, Sebastien Vievard, Nour Skaf, Vincent Deo, Nemanja Jovanovic, Frantz Martinache, Motohide Tamura, N. Jeremy Kasdin, and Benjamin A. Mazin

Published
2022
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9. SCExAO/CHARIS Near-infrared Integral Field Spectroscopy of the HD 15115 Debris Disk

Author

Kellen Lawson, Thayne Currie, John P. Wisniewski, Motohide Tamura, Glenn Schneider, Jean-Charles Augereau, Timothy D. Brandt, Olivier Guyon, N. Jeremy Kasdin, Tyler D. Groff, Julien Lozi, Jeffrey Chilcote, Klaus Hodapp, Nemanja Jovanovic, Frantz Martinache, Nour Skaf, Eiji Akiyama, Thomas Henning, Gillian R. Knapp, Jungmi Kwon, Satoshi Mayama, Michael W. McElwain, Michael L. Sitko, Ruben Asensio-Torres, Taichi Uyama, and Kevin Wagner

Subjects
Astronomy, Astrophysics
Abstract

We present new, near-infrared (1.1–2.4 μm) high-contrast imaging of the debris disk around HD 15115 with the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). The SCExAO/CHARIS resolves the disk down to ρ ∼ 0."2 (r(proj) ∼ 10 au), a factor of ∼3–5 smaller than previous recent studies. We derive a disk position angle of PA ∼ 279.°4–280.°5 and an inclination of i ∼ 85.°3–86.2.°. While recent SPHERE/IRDIS imagery of the system could suggest a significantly misaligned two-ring disk geometry, CHARIS imagery does not reveal conclusive evidence for this hypothesis. Moreover, optimizing models of both one- and two-ring geometries using differential evolution, we find that a single ring having a Hong-like scattering phase function matches the data equally well within the CHARIS field of view (ρ ≲ 1''). The disk's asymmetry, well evidenced at larger separations, is also recovered; the west side of the disk appears, on average, around 0.4 mag brighter across the CHARIS bandpass between 0farcs25 and 1''. Comparing Space Telescope Imaging Spectrograph (STIS) 50CCD optical photometry (2000–10500 Å) with CHARIS near-infrared photometry, we find a red (STIS/50CCD−CHARIS broadband) color for both sides of the disk throughout the 0farcs4–1'' region of overlap, in contrast to the blue color reported at similar wavelengths for regions exterior to ∼2''. Further, this color may suggest a smaller minimum grain size than previously estimated at larger separations. Finally, we provide constraints on planetary companions and discuss possible mechanisms for the observed inner disk flux asymmetry and color.

Published
2020
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10. No Clear, Direct Evidence for Multiple Protoplanets Orbiting LkCa 15: LkCa 15 bcd are Likely Inner Disk Signals

Author

Thayne Currie, Christian Marois, Lucas Cieza, Gijs D. Mulders, Kellen Lawson, Claudio Caceres, Dary Rodriguez-Ruiz, John Wisniewski, Olivier Guyon, Timothy D. Brandt, N. Jeremy Kasdin, Tyler D Groff, Julien Lozi, Jeffrey Chilcote, Klaus Hodapp, Nemanja Jovanovic, Frantz Martinache, Nour Skaf, Wladimir Lyra, Motohide Tamura, Ruben Asensio-Torres, Ruobing Dong, Carol Grady, Benjamin Gerard, Misato Fukagawa, Derek Hand, Masahiko Hayashi, Thomas Henning, Tomoyuki Kudo, Masayuki Kuzuhara, Jungmi Kwon, Michael W Mcelwain, and Taichi Uyama

Subjects
Astrophysics
Abstract

Two studies utilizing sparse aperture-masking (SAM) interferometry and Hα differential imaging have reported multiple Jovian companions around the young solar-mass star, LkCa 15 (LkCa 15 bcd): thefirst claimed direct detection of infant, newly formed planets (“protoplanets”). We present new near-infrared direct imaging/spectroscopy from the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) integral field spectrograph and multi-epoch thermal infrared imaging from Keck/ NIRC2 of LkCa 15 at high Strehl ratios. These data provide the first direct imaging look at the same wavelengths and in the same locations where previous studies identified the LkCa 15 protoplanets,and thus offer the first decisive test of their existence.The data do not reveal these planets. Instead,we resolve extended emission tracing adust disk with a brightness and location comparable to that claimed for LkCa 15 bcd. Forward-models attributing this signal to orbiting planets are inconsistent with the combined SCExAO/CHARIS and Keck/NIRC2 data. An inner disk provides a more compelling explanation for the SAM detections and perhaps also the claimed Hα detection of LkCa 15 b. We conclude that there is currently no clear, direct evidence for multiple protoplanets orbiting LkCa 15, although the system likely contains at least one unseen Jovian companion. To identify Jovian companions around LkCa 15 from future observations, the inner disk should be detected and its effect modeled, removed, and shown to be distinguishable from planets. Protoplanet candidates identified from similar systems should likewise be clearly distinguished from disk emission through modeling.

Published
2019
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11. Direct Imaging and Astrometric Detection of a Gas Giant Planet Orbiting an Accelerating Star

Author

Thayne Currie, G. Mirek Brandt, Timothy D. Brandt, Brianna Lacy, Adam Burrows, Olivier Guyon, Motohide Tamura, Ranger Y. Liu, Sabina Sagynbayeva, Taylor Tobin, Jeffrey Chilcote, Tyler Groff, Christian Marois, William Thompson, Simon J. Murphy, Masayuki Kuzuhara, Kellen Lawson, Julien Lozi, Vincent Deo, Sebastien Vievard, Nour Skaf, Taichi Uyama, Nemanja Jovanovic, Frantz Martinache, N. Jeremy Kasdin, Tomoyuki Kudo, Michael McElwain, Markus Janson, John Wisniewski, Klaus Hodapp, Jun Nishikawa, Krzysztof Hełminiak, Jungmi Kwon, and Masahiko Hayashi

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Multidisciplinary, Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract

Direct imaging of gas giant exoplanets provides key information on planetary atmospheres and the architectures of planetary systems. However, few planets have been detected in blind surveys used to achieve imaging detections. Using Gaia and Hipparcos astrometry we identified dynamical evidence for a gas giant planet around the nearby star HIP 99770 and then confirmed this planet by direct imaging with the Subaru Coronagraphic Extreme Adaptive Optics Project. HIP 99770 b orbits 17 astronomical units from its host star, with an insolation comparable to Jupiter's and a dynamical mass of 13.9--16.1 Jupiter masses. Its planet-to-star mass ratio (7--8$\times$10$^{-3}$) is comparable to that other directly-imaged planets. The planet's atmosphere resembles an older, less-cloudy analogue of the atmospheres of previously-imaged exoplanets around HR 8799., Authors' version of revised paper, published in Science on April 14, 2023 (passed independent peer review/was recommended for publication in Science by external referees on July 5, 2022). First joint direct imaging + astrometric discovery of an exoplanet. 49 pages, 18 figures, 6 tables

Published
2022

12. Controlling petals using fringes: discontinuous wavefront sensing through sparse aperture interferometry at Subaru/SCExAO

Author

Vincent Deo, Sébastien Vievard, Nick Cvetojevic, Kyohoon Ahn, Elsa Huby, Olivier Guyon, Sylvestre Lacour, Julien Lozi, Frantz Martinache, Barnaby Norris, Nour Skaf, and Peter G. Tuthill

Subjects
FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

Low wind and petaling effects, caused by the discontinuous apertures of telescopes, are poorly corrected -- if at all -- by commonly used workhorse wavefront sensors (WFSs). Wavefront petaling breaks the coherence of the point spread function core, splitting it into several side lobes, dramatically shutting off scientific throughput. We demonstrate the re-purposing of non-redundant sparse aperture masking (SAM) interferometers into low-order WFSs complementing the high-order pyramid WFS, on the SCExAO experimental platform at Subaru Telescope. The SAM far-field interferograms formed from a 7-hole mask are used for direct retrieval of petaling aberrations, which are almost invisible to the main AO loop. We implement a visible light dual-band SAM mode, using two disjoint 25 nm wide channels, that we recombine to overcome the one-lambda ambiguity of fringe-tracking techniques. This enables a control over petaling with sufficient capture range yet without conflicting with coronagraphic modes in the near-infrared. We present on-sky engineering results demonstrating that the design is able to measure petaling well beyond the range of a single-wavelength equivalent design., Proc. SPIE 12185 (Adaptive Optics Systems VIII), 285-297

Published
2022

13. High Contrast Imaging at the Photon Noise Limit with WFS-based PSF Calibration

Author

Olivier Guyon, Barnaby Norris, Marc-Antoine Martinod, Kyohoon Ahn, Vincent Deo, Nour Skaf, Julien Lozi, Sebastien Vievard, Sebastiaan Haffert, Thayne Currie, Jared Males, Alison Wong, and Peter Tuthill

Subjects
FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

Speckle Noise is the dominant source of error in high contrast imaging with adaptive optics system. We discuss the potential for wavefront sensing telemetry to calibrate speckle noise with sufficient precision and accuracy so that it can be removed in post-processing of science images acquired by high contrast imaging instruments. In such a self-calibrating system, exoplanet detection would be limited by photon noise and be significantly more robust and efficient than in current systems. We show initial laboratory and on-sky tests, demonstrating over short timescale that residual speckle noise is indeed calibrated to an accuracy exceeding readout and photon noise in the high contrast region. We discuss immplications for the design of space and ground high-contrast imaging systems., 12 pages, 7 figures, To appear in SPIE Proceedings of Astronomical Telescopes + Instrumentation, 2022. arXiv admin note: text overlap with arXiv:2109.13958

Published
2022

14. Images of Embedded Jovian Planet Formation At A Wide Separation Around AB Aurigae

Author

Thayne Currie, Kellen Lawson, Glenn Schneider, Wladimir Lyra, John Wisniewski, Carol Grady, Olivier Guyon, Motohide Tamura, Takayuki Kotani, Hajime Kawahara, Timothy Brandt, Taichi Uyama, Takayuki Muto, Ruobing Dong, Tomoyuki Kudo, Jun Hashimoto, Misato Fukagawa, Kevin Wagner, Julien Lozi, Jeffrey Chilcote, Taylor Tobin, Tyler Groff, Kimberly Ward-Duong, William Januszewski, Barnaby Norris, Peter Tuthill, Nienke van der Marel, Michael Sitko, Vincent Deo, Sebastien Vievard, Nemanja Jovanovic, Frantz Martinache, and Nour Skaf

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Direct images of protoplanets embedded in disks around infant stars provide the key to understanding the formation of gas giant planets like Jupiter. Using the Subaru Telescope and Hubble Space Telescope, we find evidence for a jovian protoplanet around AB Aurigae orbiting at a wide projected separation (93 au), likely responsible for multiple planet-induced features in the disk. Its emission is reproducible as reprocessed radiation from an embedded protoplanet. We also identify two structures located at 430-580 au that are candidate sites of planet formation. These data reveal planet formation in the embedded phase and a protoplanet discovery at wide, > 50 au separations characteristic of most imaged exoplanets. With at least one clump-like protoplanet and multiple spiral arms, the AB Aur system may also provide the evidence for a long-considered alternative to the canonical model for Jupiter's formation: disk (gravitational) instability., Author's personal version: 19 pages, 5 Figures, 1 Table; 32 Supplementary pages, 18 Supplementary Figures, 1 Supplementary Table; Accepted for Publication in Nature Astronomy. Published version: https://www.nature.com/articles/s41550-022-01634-x

Published
2022

15. Multiband Imaging of the HD 36546 Debris Disk: A Refined View from SCExAO/CHARIS*

Author

Kellen Lawson, Thayne Currie, John P. Wisniewski, Motohide Tamura, Jean-Charles Augereau, Timothy D. Brandt, Olivier Guyon, N. Jeremy Kasdin, Tyler D. Groff, Julien Lozi, Vincent Deo, Sebastien Vievard, Jeffrey Chilcote, Nemanja Jovanovic, Frantz Martinache, Nour Skaf, Thomas Henning, Gillian Knapp, Jungmi Kwon, Michael W. McElwain, Tae-Soo Pyo, Michael L. Sitko, Taichi Uyama, Kevin Wagner, Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France, National Astronomical Observatory of Japan (NAOJ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), University of California [Santa Barbara] (UCSB), University of California, Princeton University, NASA Goddard Space Flight Center (GSFC), National Astronomical Observatory of Japan, Subaru Telescope, 650 North A‘ohoku Place, Hilo, HI 96720, United States, University of Notre Dame [Indiana] (UND), California Institute of Technology (CALTECH), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, ISAS/JAXA, and NASA

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), 010309 optics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, FOS: Physical sciences, Astronomy and Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 01 natural sciences, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the first multi-wavelength (near-infrared; $1.1 - 2.4$ $\mu m$) imaging of HD 36546's debris disk, using the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). As a 3-10 Myr old star, HD 36546 presents a rare opportunity to study a debris disk at very early stages. SCExAO/CHARIS imagery resolves the disk over angular separations of $\rho \sim 0.25" - 1.0"$ (projected separations of $\rm{r_{proj}} \sim 25 - 101$ $\rm{au}$) and enables the first spectrophotometric analysis of the disk. The disk's brightness appears symmetric between its eastern and western extents and it exhibits slightly blue near-infrared colors on average (e.g. $J-K =-0.4\pm0.1$) $-$ suggesting copious sub-micron sized or highly porous grains. Through detailed modeling adopting a Hong scattering phase function (SPF), instead of the more common Henyey-Greenstein function, and using the differential evolution optimization algorithm, we provide an updated schematic of HD 36546's disk. The disk has a shallow radial dust density profile ($\alpha_{in} \approx 1.0$ and $\alpha_{out} \approx -1.5$), a fiducial radius of $r_0 \approx 82.7$ au, an inclination of $i \approx 79.1^\circ$, and a position angle of $\rm PA \approx 80.1^\circ$. Through spine tracing, we find a spine that is consistent with our modeling, but also with a "swept-back wing" geometry. Finally, we provide constraints on companions, including limiting a companion responsible for a marginal Hipparcos-Gaia acceleration to a projected separation of $\lesssim 0.2''$ and to a minimum mass of $\lesssim 11$ $\rm M_{Jup}$., Comment: 23 pages, 19 figures; corrected an error in the abstract, added a reference in Section 2

Published
2021
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16. ARES V: No evidence for molecular absorption in the HST WFC3 spectrum of GJ 1132 b

Author

Jeroen Bouwman, Benjamin Charnay, Quentin Changeat, William Pluriel, Pierre Drossart, Amélie Gressier, Niall Whiteford, Tiziano Zingales, Mario Morvan, Ahmed Al-Refaie, Jean-Philippe Beaulieu, Sam Wright, Michelle Fabienne Bieger, Jérémy Leconte, Nour Skaf, Mathilde Poveda, Kai Hou Yip, Giuseppe Morello, Darius Modirrousta-Galian, Ingo Waldmann, Billy Edwards, Doriann Blain, Yassin Jaziri, Flavien Kiefer, Robin Baeyens, Gloria Guilluy, Olivia Venot, Lorenzo V. Mugnai, Dipartimento di Fisica [Roma La Sapienza], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), Dipartimento di Fisica e Chimica [Palermo] (DiFC), Università degli studi di Palermo - University of Palermo, Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Instituto de Astrofisica de Canarias (IAC), Institute of Astronomy [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Fisica [Torino], Università degli studi di Torino = University of Turin (UNITO), INAF - Osservatorio Astrofisico di Torino (OATo), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Maison de la Simulation (MDLS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Subaru Telescope, National Astronomical Observatory of Japan (NAOJ), Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Centre for Exoplanet Science, School of Physical Sciences [Hobart], University of Tasmania [Hobart, Australia] (UTAS), European Union’s Horizon 2020 research and innovation program under the Marie SkłodowskaCurie grant agreement No. 895525., ANR-16-CE31-0005,e-PYTHEAS,Etude des hydrocarbures en émission et absorption dasn les exoplanètes à haute température(2016), European Project: 776403,EXOPLANET, European Project: 757858,ATMO, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Università degli studi di Torino (UNITO), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)

Subjects
010504 meteorology & atmospheric sciences, HD 3167C, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], STELLAR ATMOSPHERE MODELS, FOS: Physical sciences, SUPER-EARTH, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Spectral line, 55 CNC E, Atmosphere, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, TRANSMISSION SPECTRUM, KEPLER PLANETS, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, PLANETARY SYSTEM, HOT, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Science & Technology, Secondary atmosphere, EXOMOL LINE LISTS, ERROR-CORRECTION, James Webb Space Telescope, Astronomy and Astrophysics, Exoplanet, Grism, 13. Climate action, Space and Planetary Science, Exoplanet atmospheres, Astronomy data analysis, Hubble Space Telescope, Exoplanets, Physical Sciences, Astrophysics::Earth and Planetary Astrophysics, Wide Field Camera 3, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present a study on the spatially scanned spectroscopic observations of the transit of GJ 1132 b, a warm ($\sim$500 K) Super-Earth (1.13 R$_\oplus$) that was obtained with the G141 grism (1.125 - 1.650 $\mu$m) of the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope. We used the publicly available Iraclis pipeline to extract the planetary transmission spectra from the five visits and produce a precise transmission spectrum. We analysed the spectrum using the TauREx3 atmospheric retrieval code with which we show that the measurements do not contain molecular signatures in the investigated wavelength range and are best-fit with a flat-line model. Our results suggest that the planet does not have a clear primordial, hydrogen-dominated atmosphere. Instead, GJ 1132 b could have a cloudy hydrogen-dominated envelope, a very enriched secondary atmosphere, be airless, or have a tenuous atmosphere that has not been detected. Due to the narrow wavelength coverage of WFC3, these scenarios cannot be distinguished yet but the James Webb Space Telescope may be capable of detecting atmospheric features, although several observations may be required to provide useful constraints., Comment: 17 pages, 11 figures. Accepted for publication in AJ

Published
2021
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17. ARES IV: Probing the Atmospheres of the Two Warm Small Planets HD 106315c and HD 3167c with the HST/WFC3 Camera

Author

Sam Wright, Emmanuel Marcq, Adam Yassin Jaziri, Amélie Gressier, Quentin Changeat, Doriann Blain, Michelle Fabienne Bieger, Alexandre Santerne, Jérémy Leconte, Ahmed Al-Refaie, Darius Modirrousta-Galian, Alessandro Sozzetti, Tiziano Tsingales, William Pluriel, Pierre Drossart, Jean-Philippe Beaulieu, Gloria Guilluy, Kai Hou Yip, Niall Whiteford, Olivia Venot, Lorenzo V. Mugnai, Ingo Waldmann, Mario Morvan, Robin Baeyens, Flavien Kiefer, Billy Edwards, Angelos Tsiaras, Mathilde Poveda, Nour Skaf, Benjamin Charnay, Dipartimento di Fisica [Torino], Università degli studi di Torino = University of Turin (UNITO), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Palermo (OAPa), Dipartimento di Fisica e Chimica [Palermo] (DiFC), Università degli studi di Palermo - University of Palermo, Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Dipartimento di Fisica [Roma La Sapienza], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Maison de la Simulation (MDLS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Centre for Exoplanet Science, School of Physical Sciences [Hobart], University of Tasmania [Hobart, Australia] (UTAS), ANR-16-CE31-0005,e-PYTHEAS,Etude des hydrocarbures en émission et absorption dasn les exoplanètes à haute température(2016), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Università degli studi di Torino (UNITO), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Paris (UP)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
astronomy data analysis, Exoplanets, Exoplanet atmospheres, Hubble Space Telescope, EXOPLANET, 010504 meteorology & atmospheric sciences, Infrared, MODELS, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, 7. Clean energy, Atmosphere, METHANE, Planet, Hubble space telescope, 0103 physical sciences, PHOTOMETRY, Absorption (logic), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, SPECTRUM, Science & Technology, SPECTROSCOPY, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Radius, FRAMEWORK, Exoplanet, LINE LISTS, TRANSITING PLANET, 13. Climate action, Space and Planetary Science, Physical Sciences, Wide Field Camera 3, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present an atmospheric characterization study of two medium sized planets bracketing the radius of Neptune: HD 106315 c (R$_{\rm{P}}$=4.98 $\pm$ 0.23 R$_{\oplus}$) and HD 3167 c (R$_{\rm{P}}$=2.740$_{-0.100}^{+0.106}$ R$_{\oplus}$). We analyse spatially scanned spectroscopic observations obtained with the G141 grism (1.125 - 1.650 $\mu$m) of the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope. We use the publicly available Iraclis pipeline and TauREx3 atmospheric retrieval code and we detect water vapor in the atmosphere of both planets with an abundance of $\log_{10}[\mathrm{H_2O}]=-2.1^{+0.7}_{-1.3}$ ($\sim$5.68$\sigma$) and $\log_{10}[\mathrm{H_2O}]=-4.1^{+0.9}_{-0.9}$ ($\sim$3.17$\sigma$) for HD 106315 c and HD 3167 c, respectively. The transmission spectrum of HD 106315 c shows also a possible evidence of ammonia absorption ($\log_{10}[\mathrm {NH_3}]=-4.3^{+0.7}_{-2.0}$, $\sim$1.97$\sigma$ -even if it is not significant-), whilst carbon dioxide absorption features may be present in the atmosphere of HD 3167 c in the $\sim$1.1-1.6~$\mu$m wavelength range ($\log_{10}[\mathrm{CO_{2}}]= -2.4^{+0.7}_{-1.0}$, $\sim$3.28$\sigma$). However the CO$_2$ detection appears significant, it must be considered carefully and put into perspective. Indeed, CO$_2$ presence is not explained by 1D equilibrium chemistry models, and it could be due to possible systematics. The additional contribution of clouds, CO and CH$_4$ are discussed. HD 106315 c and HD 3167 c will be interesting targets for upcoming telescopes such as the James Webb Space Telescope (JWST) and the Atmospheric Remote-Sensing Infrared Exoplanet Large-Survey (Ariel)., Comment: Accepted for publication in AJ

Published
2021
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18. Focal plane wavefront sensing on SUBARU/SCExAO

Author

Aurélie Montmerle-Bonnefois, Frédéric Cassaing, Nemanja Jovanovic, Laurent M. Mugnier, Alison Wong, Vincent Deo, Frans Snik, Sébastien Vievard, Coline Lopez, Michael J. Wilby, Barnaby Norris, Steven P. Bos, Thayne Currie, Christoph U. Keller, Mamadou N'Diaye, Jean-François Sauvage, Nour Skaf, Frantz Martinache, Olivier Guyon, Masen Lamb, Ananya Sahoo, Kelsey Miller, Julien Lozi, National Astronomical Observatory of Japan (NAOJ), Astrobiology Center of Nins, DTIS, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, California Institute of Technology (CALTECH), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], DOTA, ONERA, Université Paris Saclay [Châtillon], Schreiber, Laura, Schmidt, Dirk, and Vernet, Elise

Subjects
High contrast imaging, LOW WIND EFFECT, FOS: Physical sciences, 01 natural sciences, 010309 optics, [SPI]Engineering Sciences [physics], Optics, Wind effect, 0103 physical sciences, Adaptive optics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Focal plane wavefront sensing, Physics, Wavefront, [PHYS]Physics [physics], [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, CORONOGRAPHY, Detector, Spiders, SCEXAO, Cardinal point, CORONAGRAPHY, Adaptive optics systems, business, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Focal plane wavefront sensing is an elegant solution for wavefront sensing since near-focal images of any source taken by a detector show distortions in the presence of aberrations. Non-Common Path Aberrations and the Low Wind Effect both have the ability to limit the achievable contrast of the finest coronagraphs coupled with the best extreme adaptive optics systems. To correct for these aberrations, the Subaru Coronagraphic Extreme Adaptive Optics instrument hosts many focal plane wavefront sensors using detectors as close to the science detector as possible. We present seven of them and compare their implementation and efficiency on SCExAO. This work will be critical for wavefront sensing on next generation of extremely large telescopes that might present similar limitations., Comment: SPIE proceeding : Astronomical Telescopes + Instrumentation 2020. arXiv admin note: text overlap with arXiv:1912.10179

Published
2020
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19. ARES. II. Characterizing the Hot Jupiters WASP-127 b, WASP-79 b, and WASP-62b with the Hubble Space Telescope

Author

William Pluriel, Jean-Philippe Beaulieu, Tiziano Zingales, Doriann Blain, Nour Skaf, Quentin Changeat, Sam Wright, Benjamin Charnay, Darius Modirrousta-Galian, Amélie Gressier, Adam Yassin Jaziri, Ahmed Al-Refaie, Robin Baeyens, Billy Edwards, Pierre Drossart, Mathilde Poveda, Ingo Waldmann, Michelle Fabienne Bieger, Jérémy Leconte, Niall Whiteford, Kai Hou Yip, Mario Morvan, Angelos Tsiaras, Flavien Kiefer, Gloria Guilluy, Olivia Venot, Lorenzo V. Mugnai, Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ECLIPSE 2020, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Paris (UP)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Maison de la Simulation (MDLS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Dipartimento di Fisica [Torino], Università degli studi di Torino (UNITO), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), INAF - Osservatorio Astronomico di Palermo (OAPa), Department of Physics [Roma La Sapienza], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Centre for Exoplanet Science, School of Physical Sciences [Hobart], University of Tasmania [Hobart, Australia] (UTAS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), Dipartimento di Fisica [Roma La Sapienza], and Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA)

Subjects
Exoplanet atmospheres (487), 010504 meteorology & atmospheric sciences, Gas giant, Exoplanet astronomy, MOLECULAR OPACITIES, Exoplanet atmospheres, Astronomy data analysis, Hubble Space Telescope, MODELS, Unified Astronomy Thesaurus concepts: Exoplanet astronomy (486), Astronomy & Astrophysics, 01 natural sciences, DWARF, Astronomy data analysis (1858), CHEMISTRY, Hubble space telescope, 0103 physical sciences, Hot Jupiter, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Science & Technology, SPECTROSCOPY, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy, Astronomy and Astrophysics, Hubble Space Telescope (761), EXOPLANETS, Grism, On board, 13. Climate action, Space and Planetary Science, Physical Sciences, ROTATION, Wide Field Camera 3, ATMOSPHERIC CIRCULATION, PLANETS
Abstract

International audience; This paper presents the atmospheric characterization of three large, gaseous planets: WASP-127 b, WASP-79 b, and WASP-62 b. We analyzed spectroscopic data obtained with the G141 grism (1.088-1.68 μm) of the Wide Field Camera 3 on board the Hubble Space Telescope using the Iraclis pipeline and the TauREx3 retrieval code, both of which are publicly available. For WASP-127 b, which is the least dense planet discovered so far and is located in the short-period Neptune desert, our retrieval results found strong water absorption corresponding to an abundance of log(H2O) = -2.71 +0.78−1.05 and absorption compatible with an iron hydride abundance of log(FeH) = −5.25+0.88−1.10, with an extended cloudy atmosphere. We also detected water vapor in the atmospheres of WASP-79 b and WASP-62 b, with best-fit models indicating the presence of iron hydride, too. We used the Atmospheric Detectability Index as well as Bayesian log evidence to quantify the strength of the detection and compared our results to the hot Jupiter population study by Tsiaras et al. While all the planets studied here are suitable targets for characterization with upcoming facilities such as the James Webb Space Telescope and Ariel, WASP-127 b is of particular interest due to its low density, and a thorough atmospheric study would develop our understanding of planet formation and migration. * ARES: Ariel Retrieval of Exoplanets School.

Published
2020
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20. ARES I: WASP-76 b, A Tale of Two HST Spectra

Author

Sam Wright, Angelos Tsiaras, Mario Morvan, Mathilde Poveda, Ahmed Al-Refaie, Pierre Drossart, Gloria Guilluy, Amélie Gressier, Olivia Venot, William Pluriel, Lorenzo V. Mugnai, Flavien Kiefer, Tiziano Zingales, Niall Whiteford, Robin Baeyens, Ingo Waldmann, Billy Edwards, Adam Yassin Jaziri, Jean-Philippe Beaulieu, Darius Modirrousta-Galian, Doriann Blain, Jake Taylor, Quentin Changeat, Nour Skaf, Benjamin Charnay, Michelle Fabienne Bieger, Jérémy Leconte, Kai Hou Yip, Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Dipartimento di Fisica [Torino], Università degli studi di Torino (UNITO), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), ECLIPSE 2020, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Palermo (OAPa), Dipartimento di Fisica e Chimica [Palermo] (DiFC), Università degli studi di Palermo - University of Palermo, Department of Physics [Roma La Sapienza], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Maison de la Simulation (MDLS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Centre for Exoplanet Science, School of Physical Sciences [Hobart], University of Tasmania [Hobart, Australia] (UTAS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Oxford, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), and Dipartimento di Fisica [Roma La Sapienza]

Subjects
Brightness, 010504 meteorology & atmospheric sciences, Exoplanet atmospheres, Exoplanet atmospheric composition, Hubble Space Telescope, Astrophysics - Earth and Planetary Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Spectral line, Atmosphere, Jupiter, HAT-P-7B, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, MOLECULAR LINE LISTS, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, HOT, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Science & Technology, Astronomy and Astrophysics, ATMOSPHERE, GIANT EXOPLANET, Grism, RESOLUTION, Transmission (telecommunications), 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physical Sciences, INFERENCE, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Wide Field Camera 3, STARS
Abstract

We analyse the transmission and emission spectra of the ultra-hot Jupiter WASP-76b, observed with the G141 grism of the Hubble Space Telescope's Wide Field Camera 3 (WFC3). We reduce and fit the raw data for each observation using the open-source software Iraclis before performing a fully Bayesian retrieval using the publicly available analysis suite TauRex 3. Previous studies of the WFC3 transmission spectra of WASP-76 b found hints of titanium oxide (TiO) and vanadium oxide (VO) or non-grey clouds. Accounting for a fainter stellar companion to WASP-76, we reanalyse this data and show that removing the effects of this background star changes the slope of the spectrum, resulting in these visible absorbers no longer being detected, eliminating the need for a non-grey cloud model to adequately fit the data but maintaining the strong water feature previously seen. However, our analysis of the emission spectrum suggests the presence of TiO and an atmospheric thermal inversion, along with a significant amount of water. Given the brightness of the host star and the size of the atmospheric features, WASP-76 b is an excellent target for further characterisation with HST, or with future facilities, to better understand the nature of its atmosphere, to confirm the presence of TiO and to search for other optical absorbers., Accepted for publication in AJ

Published
2020
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21. Validating advanced wavefront control techniques on the SCExAO testbed/instrument

Author

Marc-Antoine Martinod, Nour Skaf, Damien Gratadour, Eduardo Bendek, Arnaud Sevin, Nemanja Jovanovic, Olivier Guyon, Jared R. Males, Sébastien Vievard, Mamadou N'Diaye, Vincent Deo, Hatem Ltaief, Tyler D. Groff, Eugene Pluzhnyk, Alison Wong, Thayne Currie, Ruslan Belikov, Kelsey Miller, Frans Snik, Takayuki Kotani, Ananya Sahoo, Barnaby Norris, Motohide Tamura, Tomoyuki Kudo, Julien Lozi, Coline Lopez, Michael P. Fitzgerald, Hajime Kawahara, Steven P. Bos, Benjamin A. Mazin, Frantz Martinache, Schreiber, L., Schmidt, D., Vernet, E., Schreiber, Laura, Schmidt, Dirk, and Vernet, Elise

Subjects
Hardware architecture, Scientific instrument, Wavefront, Software, business.industry, Computer science, Modular design, business, Sensor fusion, Adaptive optics, Computer hardware, Deformable mirror
Abstract

The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) serves both a science instrument in operation, and a prototyping platform for integrating and validating advanced wavefront control techniques. It provides a modular hardware and software environment optimized for flexible prototyping, reducing the time from concept formulation to on-sky operation and validation. This approach also enables external research group to deploy and test new hardware and algorithms. The hardware architecture allows for multiple subsystems to run concurrently, sharing starlight by means of dichroics. The multiplexing lends itself to running parallel experiments simultaneously, and developing sensor fusion approaches for increased wavefront sensing sensitivity and reliability. Thanks to a modular realtime control software architecture designed around the CACAO package, users can deploy WFS/C routines with full low-latency access to all cameras data streams. Algorithms can easily be shared with other cacao-based AO systems at Magellan (MagAO-X) and Keck. We highlight recent achievements and ongoing activities that are particularly relevant to the development of high contrast imaging instruments for future large ground-based telescopes (ELT, TMT, GMT) and space telescopes (HabEx, LUVOIR). These include predictive control and sensor fusion, PSF reconstruction from AO telemetry, integrated coronagraph/WFS development, focal plane speckle control with photon counting MKIDS camera, and fiber interferometry. We also describe upcoming upgrades to the WFS/C architecture: a new 64x64 actuator first stage DM, deployment of a beam switcher for concurrent operation of SCExAO with other science instruments, and the ULTIMATE upgrade including deployment of multiple LGS WFSs and an adaptive secondary mirror.

Published
2020

22. SCExAO, an instrument with a dual purpose: perform cutting-edge science and develop new technologies

Author

Naruhisa Takato, David S. Doelman, Jeremy Kasdin, Tyler D. Groff, Nour Skaf, Elsa Huby, Mamadou N'Diaye, Jeffrey Chilcote, Ben Mazin, Michael J. Ireland, Frantz Martinache, Nemanja Jovanovic, Thayne Currie, Christophe Clergeon, Hideki Takami, Prashant Pathak, Sean Goebel, Sébastien Vievard, Peter G. Tuthill, Barnaby Norris, Takayuki Kotani, Ananya Sahoo, Tomoyuki Kudo, Nick Cvetojevic, M. Hayashi, Alex B. Walter, Justin Knight, Frans Snik, Olivier Guyon, Hajime Kawahara, Yosuke Minowa, Julien Lozi, Sylvestre Lacour, Motohide Tamura, Subaru Telescope, National Astronomical Observatory of Japan (NAOJ), Wyant College of Optical Sciences [University of Arizona], University of Arizona, National Institutes of Natural Sciences [Tokyo] (NINS), California Institute of Technology (CALTECH), Institute for astronomy [Hilo, Hawaï], University of Hawai'i [Hilo], Graduate University for Advanced Studies [Hayama] (SOKENDAI), Macquarie University, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California [Santa Barbara] (UCSB), University of California, The University of Tokyo (UTokyo), Australian National University (ANU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center (GSFC), Stanford University, Princeton University, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France., Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Close, Laird M., Schreiber, Laura, Schmidt, Dirk, Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), and COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)

Subjects
Infrared, Computer science, Segmented mirror, Polarimetry, FOS: Physical sciences, 7. Clean energy, 01 natural sciences, law.invention, 010309 optics, Telescope, Integral field spectrograph, Optics, law, 0103 physical sciences, Adaptive optics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Wavefront, [PHYS]Physics [physics], business.industry, Exoplanet, [SDU]Sciences of the Universe [physics], Subaru Telescope, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument is an extremely modular high-contrast instrument installed on the Subaru telescope in Hawaii. SCExAO has a dual purpose. Its position in the northern hemisphere on a 8-meter telescope makes it a prime instrument for the detection and characterization of exoplanets and stellar environments over a large portion of the sky. In addition, SCExAO's unique design makes it the ideal instrument to test innovative technologies and algorithms quickly in a laboratory setup and subsequently deploy them on-sky. SCExAO benefits from a first stage of wavefront correction with the facility adaptive optics AO188, and splits the 600-2400 nm spectrum towards a variety of modules, in visible and near infrared, optimized for a large range of science cases. The integral field spectrograph CHARIS, with its J, H or K-band high-resolution mode or its broadband low-resolution mode, makes SCExAO a prime instrument for exoplanet detection and characterization. Here we report on the recent developments and scientific results of the SCExAO instrument. Recent upgrades were performed on a number of modules, like the visible polarimetric module VAMPIRES, the high-performance infrared coronagraphs, various wavefront control algorithms, as well as the real-time controller of AO188. The newest addition is the 20k-pixel Microwave Kinetic Inductance Detector (MKIDS) Exoplanet Camera (MEC) that will allow for previously unexplored science and technology developments. MEC, coupled with novel photon-counting speckle control, brings SCExAO closer to the final design of future high-contrast instruments optimized for Giant Segmented Mirror Telescopes (GSMTs)., 12 pages, 9 figures, conference proceedings (SPIE Astronomical telescopes and instrumentation 2018)

Published
2018
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23. Laboratory and On-sky Validation of the Shaped Pupil Coronagraph’s Sensitivity to Low-order Aberrations With Active Wavefront Control.

Author

Thayne Currie, N. Jeremy Kasdin, Tyler D. Groff, Julien Lozi, Nemanja Jovanovic, Olivier Guyon, Timothy Brandt, Frantz Martinache, Jeffrey Chilcote, Nour Skaf, Jonas Kuhn, Prashant Pathak, and Tomoyuki Kudo

Subjects
CORONAGRAPHS, OPTICAL aberrations, WAVEFRONTS (Optics)
Abstract

We present early laboratory simulations and extensive on-sky tests validating of the performance of a shaped pupil coronagraph (SPC) behind an extreme-AO corrected beam of the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. In tests with the SCExAO internal source/wavefront error simulator, the normalized intensity profile for the SPC degrades more slowly than for the Lyot coronagraph as low-order aberrations reduce the Strehl ratio from extremely high values (S.R. ∼ 0.93–0.99) to those characteristic of current ground-based extreme AO systems (S.R. ∼ 0.74–0.93) and then slightly lower values down to S.R. ∼ 0.57. On-sky SCExAO data taken with the SPC and other coronagraphs for brown dwarf/planet-hosting stars HD 1160 and HR 8799 provide further evidence for the SPC’s robustness to low-order aberrations. From H-band Strehl ratios of 80% to 70%, the Lyot coronagraph’s performance versus that of the SPC may degrade even faster on sky than is seen in our internal source simulations. The 5-σ contrast also degrades faster (by a factor of two) for the Lyot than the SPC. The SPC we use was designed as a technology demonstrator only, with a contrast floor, throughput, and outer working angle poorly matched for SCExAO’s current AO performance and poorly tuned for imaging the HR 8799 planets. Nevertheless, we detect HR 8799 cde with SCExAO/CHARIS using the SPC in broadband mode, where the S/N for planet e is within 30% of that obtained using the vortex coronagraph. The shaped-pupil coronagraph is a promising design demonstrated to be robust in the presence of low-order aberrations and may be well-suited for future ground and space-based direct imaging observations, especially those focused on follow-up exoplanet characterization and technology demonstration of deep contrast within well-defined regions of the image plane. [ABSTRACT FROM AUTHOR]

Published
2018
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