N. Jeremy Kasdin

Abstract We present the discovery of a superjovian planet around the young A5 star HIP 54515, detected using precision astrometry from the Hipparcos Gaia Catalogue of Accelerations and high-contrast imaging with SCExAO/CHARIS from the recently commenced OASIS program. SCExAO/CHARIS detects HIP 54515 b in five epochs 0 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>.</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>″</mml:mi> </mml:mrow> </mml:mover> </mml:math> 145–0 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>.</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>″</mml:mi> </mml:mrow> </mml:mover> </mml:math> 192 from the star (∼3–4 λ / D at 1.65 μ m), exhibiting clockwise orbital motion. HIP 54515 b lies near the M/L transition with a luminosity of log( L / L ⊙ ) ∼−3.52 ± 0.03. Dynamical modeling constrains its mass and mass ratio to be <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>17.7</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>4.9</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>7.6</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> M Jup and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>0.0090</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.0024</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.0036</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> and favors a ∼25 au semimajor axis. HIP 54515 b adds to a growing list of superjovian planets with moderate eccentricities ( e ≈ 0.4). Now, the third planet discovered from surveys combining high-contrast extreme adaptive optics imaging with precision astrometry, HIP 54515 b, should help improve empirical constraints on the luminosity evolution and eccentricity distribution of the most massive planets. It may also provide a key technical test of the Roman Space Telescope Coronagraph Instrument’s performance in the low stellar flux, small angular separation limit, and a demonstration of its ability to yield constrainable planet spectral properties.

Abstract We present the OASIS survey program discovery of a substellar companion orbiting the young A1V star HIP 71618, detected using precision astrometry from Gaia and Hipparcos and high-contrast imaging with SCExAO/CHARIS and Keck/NIRC2. Atmospheric modeling favors a spectral type of M5–M8 and a temperature of ∼2700 ± 100 K. Dynamical modeling constrains HIP 71618 B’s mass to be <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>60</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>21</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>27</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> M Jup or <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>65</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>29</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>54</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> M Jup , depending on the adopted companion mass prior. It has a nearly-edge-on 11 au orbit with high eccentricity. HIP 71618 B will be located within the Roman Coronagraph’s dark-hole region during the instrument’s technological demonstration phase. A high-signal-to-noise-ratio detection of HIP 71618 B at 575 nm would demonstrate a 5 σ contrast of 10 −7 or better. The system is also located within or very close to the Roman Coronagraph’s Continuous Viewing Zone—near multiple candidate reference stars for dark-hole digging—and its primary is bright ( V ≈ 5). The suitability of HIP 71618 as a potential Roman Coronagraph target for demonstrating the instrument’s core requirement (TTR5) should motivate the timely deep vetting of candidate reference stars.

We present the OASIS survey program discovery of a substellar companion orbiting the young A1V star HIP 71618, detected using precision astrometry from Gaia and Hipparcos and high-contrast imaging with SCExAO/CHARIS and Keck/NIRC2. Atmospheric modeling favors a spectral type of M5--M8 and a temperature of $\sim$2700 $\pm$ 100 $K$. Dynamical modeling constrains HIP 71618 B's mass to be ${60}_{-21}^{+27}$ $M_{\rm Jup}$ or ${65}_{-29}^{+54}$ $M_{\rm Jup}$, depending on the adopted companion mass prior. It has a nearly edge-on, 11 au-orbit with a high eccentricity. HIP 71618 B will be located within Roman Coronagraph's dark hole region during the instrument's technological demonstration phase. A high signal-to-noise ratio detection of HIP 71618 B at 575 nm would demonstrate a 5-$σ$ contrast of 10$^{-7}$ or better. The system is also located within or very close to Roman's Continuous Viewing Zone -- near multiple candidate reference stars for dark-hole digging -- and its primary is bright ($V$ $\approx$ 5). The suitability of HIP 71618 as one potential Roman Coronagraph target for demonstrating the instrument's core requirement (TTR5) should motivate the timely, deep vetting of candidate reference stars.

We present the discovery of a superjovian planet around the young A5 star HIP 54515, detected using precision astrometry from the Hipparcos Gaia Catalogue of Accelerations and high-contrast imaging with SCExAO/CHARIS from the recently-commenced OASIS program. SCExAO/CHARIS detects HIP 54515 b in five epochs 0\farcs{}145--0\farcs{}192 from the star ($\sim$3--4 $λ$/D at 1.65 $μm$), exhibiting clockwise orbital motion. HIP 54515 b lies near the M/L transition with a luminosity of log(L/L$_{\rm \odot}$) $\sim$ -3.52 $\pm$ 0.03. Dynamical modeling constrains its mass and mass ratio to be ${17.7}_{-4.9}^{+7.6}$ $M_{\rm Jup}$ and ${0.0090}_{-0.0024}^{+0.0036}$ and favors a $\sim$25 au semimajor axis. HIP 54515 b adds to a growing list of superjovian planets with moderate eccentricities (e $\approx$ 0.4). Now the third planet discovered from surveys combining high-contrast extreme adaptive optics imaging with precision astrometry, HIP 54515 b should help improve empirical constraints on the luminosity evolution and eccentricity distribution of the most massive planets. It may also provide a key technical test of the Roman Space Telescope Coronagraph Instrument's performance in the low stellar flux, small angular separation limit and a demonstration of its ability to yield constrainable planet spectral properties.

Over the past two decades, thousands of confirmed exoplanets have been detected. The next major challenge is to characterize these other worlds and their stellar systems. Much information on the composition and formation of exoplanets and circumstellar debris disks can only be achieved via direct imaging. Direct imaging is challenging because of the small angular separations (<1 arcsec) and high star-to-planet flux ratios such as ∼109 for a Jupiter analog or ∼1010 for an Earth analog in the visible. Atmospheric turbulence prohibits reaching such high flux ratios on the ground, so observations must be made above the Earth’s atmosphere. The Nancy Grace Roman Space Telescope (Roman), planned to launch in late 2026, will be the first space-based observatory to demonstrate high-contrast imaging with active wavefront control using its Coronagraph Instrument. The instrument’s main purpose is to mature the various technologies needed for a future flagship mission to image and characterize Earth-like exoplanets. These technologies include two high-actuator-count deformable mirrors, photon-counting detectors, two complementary wavefront sensing and control loops, and two different coronagraph types. We describe the complete set of flight masks in the Roman Coronagraph Instrument, their intended combinations, and how they were laid out, fabricated, and measured.

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 = <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>47.5</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>4.7</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>2.5</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> o ) and dynamical mass ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>52.8</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2.4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>2.6</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> 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.

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 &lt; 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 &gt; 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.

With the commencement of the development of the Habitable Worlds Observatory, it is imperative that the community has an understanding of (1) the stability requirements for the observatory to inform the design and (2) the gains expected from post-processing to inform observing scenarios and science yield estimates. We demonstrate that a previously developed, photon-efficient dark zone maintenance (DZM) algorithm that corrects quasi-static wavefront error drifts using only science images is compatible with traditional post-processing techniques. Further, we augment the DZM algorithm to estimate the coherent and incoherent light separately and introduce three novel post-processing techniques that leverage the concurrent estimation of coherent and incoherent light. With the DZM algorithm implemented on the High-contrast imager for Complex Aperture Telescopes testbed at the Space Telescope Science Institute, artificial drifts are injected as a random walk on a set of deformable mirrors and are corrected with DZM. We present an injected fake planet recovered in post-processing using a variety of techniques, such as angular differential imaging (ADI), and three additional techniques: incoherent accumulated imaging, software-based coherent differential imaging, and coherent reference differential imaging. All post-processing techniques can recover an injected planet at the same contrast level as the dark zone background contrast (∼8×10−8), and the ADI technique is shown to recover a 4×10−8 planet in a 8×10−8 dark zone. For a space-based observatory, this would mean that, if the instrument can reach a contrast level, we can maintain it and recover a planet that is undetectable in a single frame.

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 ($λ_{\rm o}$ = 1.1--2.4 $μm$) over angular separations of $ρ$ $\approx$ 0.13" to 1.1" ($\sim$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 $ρ$ $&lt;$ 0.3" out to larger distances clockwise from the protoplanet AB Aur b, coincident with the ALMA-detected $CO$ gas spiral. While AB Aur b is detectable in complementary total intensity data, it is a non-detection in polarized light at $λ$ $&gt;$ 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 $\sim$ 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.

We summarize the current best polychromatic (∼10% to 20% bandwidth) contrast performance demonstrated in the laboratory by different starlight suppression approaches and systems designed to directly characterize exoplanets around nearby stars. We present results obtained by internal coronagraph and external starshade experimental testbeds using entrance apertures equivalent to off-axis or on-axis telescopes, either monolithic or segmented. For a given angular separation and spectral bandwidth, the performance of each starlight suppression system is characterized by the values of “raw” contrast (before image processing), off-axis (exoplanet) core throughput, and post-calibration contrast (the final 1-sigma detection limit of off-axis point sources, after image processing). Together, the first two parameters set the minimum exposure time required for observations of exoplanets at a given signal-to-noise, i.e., assuming perfect subtraction of background residuals down to the photon noise limit. In practice, residual starlight speckle fluctuations during the exposure will not be perfectly estimated nor subtracted, resulting in a finite post-calibrated contrast and exoplanet detection limit whatever the exposure time. To place the current laboratory results in the perspective of the future Habitable Worlds Observatory (HWO) mission, we simulate visible observations of a fiducial Earth/Sun twin system at 12 pc, assuming a 6 m (inscribed diameter) collecting aperture and a realistic end-to-end optical throughput. The exposure times required for broadband exo-Earth detection (20% bandwidth around λ=0.55 μm) and visible spectroscopic observations (R=70) are then computed assuming various levels of starlight suppression performance, including the values currently demonstrated in the laboratory. Using spectroscopic exposure time as a simple metric, our results point to key starlight suppression system design performance improvements and trades to be conducted in support of HWO’s exoplanet science capabilities. These trades may be explored via numerical studies, lab experiments, and high-contrast space-based observations and demonstrations.

Kernel phase interferometry is a data analysis technique that allows for the detection of moderate contrast asymmetries below &lambda;/<i>d</i> in high-Strehl images. The technique is of particular interest within the area of planet formation, where the asymmetries around a young star can be from disk features or protoplanet candidates. Here we examine the performance achieved by a kernel phase interferometry program using the SCExAO/CHARIS integral field spectrograph on the Subaru telescope. We investigate the quality of the kernel phases as a function of the Strehl ratio of the observations. We also find that all but the highest quality observations are limited by random, as opposed to systematic errors. Finally we conduct a preliminary analysis of observations of V1247 Orionis, where we tentatively detect the presence of a previously identified companion candidate.

With the commencement of the development of the Habitable Worlds Observatory, it is imperative that the community has an understanding of (1) the stability requirements for the observatory to inform the design and (2) the gains expected from post-processing to inform observing scenarios and science yield estimates. We demonstrate that a previously developed, photon-efficient dark-zone maintenance (DZM) algorithm, that corrects quasi-static wavefront error drifts by using only science images, is compatible with traditional post-processing techniques. Further, we augment the DZM algorithm to estimate the coherent and incoherent light separately and introduce three novel post-processing techniques that leverage the concurrent estimation of coherent and incoherent light. With the DZM algorithm implemented on the High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed at the Space Telescope Science Institute (STScI), artificial drifts are injected as a random walk on a set of deformable mirrors (DMs) and are corrected with DZM. An injected fake planet is recovered in post-processing using a variety of techniques, such as angular differential imaging (ADI), and three novel techniques presented in this paper: incoherent accumulated imaging (IAI), software-based coherent differential imaging (CDI), and coherent reference differential imaging (CoRDI). All post-processing techniques can recover an injected planet at the same contrast level as the dark-zone background contrast (∼ 8 &times; 10⁻⁸), and the ADI technique is shown to recover a 4 &times; 10⁻⁸ planet in a 8 &times; 10⁻⁸ dark zone. For a space-based observatory, this would mean that if the instrument can reach a contrast level, we can maintain it and recover a planet that is undetectable in a single frame.

In preparation for the operational phase of the Nancy Grace Roman Space Telescope, NASA has created the Coronagraph Community Participation Program (CPP) to prepare for and execute Coronagraph Instrument technology demonstration observations. The CPP is composed of 7 small, US-based teams, selected competitively via the Nancy Grace Roman Space Telescope Research and Support Participation Opportunity, members of the Roman Project Team, and international partner teams from ESA, JAXA, CNES, and the Max Planck Institute for Astronomy. The primary goals of the CPP are to prepare simulation tools, target databases, and data reduction software for the execution of the Coronagraph Instrument observation phase. Here, we present the current status of the CPP and its working groups, along with plans for future CPP activities up through Roman’s launch. We also discuss plans to potentially enable future commissioning of currently-unsupported modes.

The Nancy Grace Roman Space Telescope’s Coronagraph Instrument will for the first time demonstrate active wavefront sensing and control for a space-based coronagraph, and may image the first planet in reflected light. The Community Participation Program has been initiated to engage members of the broader scientific community in the preparation for its planned launch in late 2026/early 2027. Here we will present the on-going work of the Data Reduction and Simulations working group, one of the four working groups within the Community Participation Program. The working group is charged with the development of the data reduction and postprocessing pipeline for the on-sky data and the development of a simulation suite to aid in the preparation and planning of Roman Coronagraph observations.

We present follow-up SCExAO/CHARIS $H$ and $K$-band (R $\sim$ 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 $T_{\rm eff}$ = 1250 $K$, log(g) = 5, and $R$ = 0.97 $R_{\rm J}$ and 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_{\rm J}$) than derived from imaging data and \textit{Gaia} eDR3 astrometry data alone. HD 33632 Ab should be a prime target for multi-band imaging and spectroscopy with the \textit{James Webb Space Telescope} and the \textit{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.

Abstract Discovering new actively accreting protoplanets is crucial to answering open questions about planet formation. However, identifying such planets at orbital distances where they are expected to be abundant is extremely challenging, both due to the technical requirements and large distances to star-forming regions. Here we use the kernel phase interferometry (KPI) technique to search for companions around the ∼6 and ∼8 Myr old Herbig Ae stars MWC 758 and MWC 480. KPI is a data analysis technique that is sensitive to moderate asymmetries, arising from, e.g., a circumstellar disk or companions with contrasts of up to 6–8 mag, at separations down to and even below the classical Rayleigh diffraction limit (∼1.2 λ / D ). Using the high-spectral-resolution K -band mode of the SCExAO/CHARIS integral field spectrograph, we search for both excess Br- γ line emission and continuum emission from companions around MWC 480 and MWC 758. We are able to set limits on the presence of rapidly accreting protoplanets and brown dwarfs between 4 and 16 au, well interior to those of previous studies. In Br- γ , we set limits on excess line emission equivalent to accretion rates ranging from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>5</mml:mn> </mml:mrow> </mml:msup> <mml:msubsup> <mml:mi>M</mml:mi> <mml:mi>j</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> <mml:mi>.</mml:mi> <mml:msup> <mml:mi>yr</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>6</mml:mn> </mml:mrow> </mml:msup> <mml:msubsup> <mml:mi>M</mml:mi> <mml:mi>j</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> <mml:mi>.</mml:mi> <mml:msup> <mml:mi>yr</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> . Our achievable contrasts demonstrate that KPI using SCExAO/CHARIS is a promising technique to search for giant accreting protoplanets at smaller separations compared to conventional imaging.

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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>L</mml:mi> <mml:mo accent="false">′</mml:mo> </mml:math> photometry indicate that it is an L/T transition object. A comparison of the JHK + L <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo accent="false">′</mml:mo> </mml:math> 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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>23.8</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>6.1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>8.7</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> au, a dynamical companion mass of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>30</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>12</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>31</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> 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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>23.6</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>7.4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>9.1</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> 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.

International audience

Abstract In Fall 2020, the University of San Francisco (USF) launches a new undergraduate Engineering program structured to integrate access, inclusion, and diversity, with specific emphasis on the representation of women and students from underrepresented populations. To do this, the programmatic structure emphasizes asset-based pedagogy, ongoing community engagement, and project-based learning throughout the undergraduate experience. Program Philosophy (Context) USF is committed to advancing social justice through intentional recruitment, retention, development, and support of diverse students, faculty, staff, and advisory board members. Rooted in the Jesuit approach to education, the Engineering Program exists within USF's broader culture which embraces a holistic approach to care for the mind, body, and spirit of each community member. Faculty members see it as their responsibility to know students on a personal level, facilitating a student's self-understanding that includes how their own background (and that of their peers) is part of their engineering toolkit. The goal of education is not only to impart intellectual knowledge or professional skills, but also to provide opportunities for personal formation and reflection, so that students grow as agents of change. We believe that this person-centered approach to program and curriculum design is essential to an Engineering program that is inclusive.This is parallel to the asset-based theory, which recognizes the cultural wealth that diverse student populations contribute to the field. Practice Development: Design phase and foundational principles Program structure was created with an explicit commitment to evidence-based approaches in pedagogical research and the personal experiences of successful engineers from underrepresented backgrounds. The curriculum is grounded in asset-based theory and project-based learning. Best practices were adopted from reports such as AAUW's Solving the Equation and the NAE's The Engineer of 2020: Visions of Engineering in the New Century. We held workshops with women and people of color who hold senior leadership and engineering positions. Questions focused on identifying what drew them to engineering and what was essential in helping them to persist and succeed. Faculty also attended a week-long workshop at Olin College aimed to promote project-based learning and transformative engineering education Key themes that emerged from these experiences included: the importance of mentoring and engineering community development, both during and after graduation; the role of interdisciplinary education in engineering problems; and the value of diverse ways of learning and doing. These inputs shaped a curricular framework that includes four pillars to be integrated across courses: a) Hands-on learning within the context of real-world problems, including project courses in all four years to help students connect theory to application; b) A focus on community-engagement, including a cultural immersion experience after the first year to provide students with an early opportunity to engage directly with communities; c) Building inter-and cross-disciplinary collaboration into student projects; and d) Explicitly conceptualizing students, projects, and teams outside of traditionally represented demographics and stereotypes. Practice Support: Resources and Representation Key structural elements were created to support these pillars, including a summer support experience ("Summer Zero") designed to ensure equitable access to program content and a MakerSpace designed with accessibility in mind. "Summer Zero" establishes early mentorship and community development, scaffolding first year students with resources. The primary goals are to support community bonding and habit-building through workshops, math, writing and a coding project. On its own, this would be a major undertaking. The phenomenon of the COVID-19 pandemic has increased this challenge, exposing many of the underlying social inequities that this program is intended to address, from unequal access to financial aid to the digital divide to housing insecurity. The Innovation Hive is a hands-on learning space (Makerspace) that is hosted by the Engineering Program and central to the project-based curriculum, while remaining open to any member of the university community. The design process for the Innovation Hive included focus groups with student leaders recommended to program staff by the USF Office of Student Disability Services. Student focus groups discussed equipment use and space layout to consider the range of abilities represented by students on campus. Additionally, we recognize that a diverse student body requires adequate representation throughout the process of engagement and education. Recruiting materials for the first year were developed to showcase our commitments to inclusivity; the promotional imagery centrally features students of color and non-binary students. Community engagement opportunities and consistent project-based learning create a more human-oriented engineering foundation. It is documented that supporting communities is a common reason for women and people from marginalized back grounds choose engineering. Our initial class is expected to be 44% women, 29% Hispanic, 11% Black, 21% Asian, 14% mixed-race, and 25% white, with all reported underrepresented minorities significantly above the national averages. We recognize, though, that the incoming class demographics is only the first piece of this puzzle. Faculty and staff recruitment is another way student-centered representation matters. Our initial team, composed of existing USF faculty, staff, and administrators is comprised of 47% women and 19% faculty of color from ten different departments and offices across campus. Our three initial faculty hires in Engineering have all been women. Additionally, invitations to our program advisory board have included leaders from diverse backgrounds and fields. Advisory board members represent technology firms, construction management, K-12 MakerSpace education, and government agencies. Board members are committed to supporting the program success as aligned with diversity and inclusion goals in mind. Process Improvement as Practice We understand that creating inclusion is a process that is never finished. In addition to the initial program development and recruitment efforts, the university and program are committed to an adaptive process that includes reflection and continuous improvement. Personal and professional development are necessary for faculty, staff, and administration. USF regularly hosts workshops, bringing in scholars in inclusion and equity such as Mica Estrada who presented her work (Spring 2020) evaluating effective retention techniques for students from underrepresented backgrounds. Learning communities are developed regularly, both campus-wide and within the new Engineering Program. Our Innovation Hive Faculty Director will be running a learning community on project-based learning, with conversations around how student engineering projects can support inclusive learning experiences. Additionally, topics such as trauma-informed pedagogy are provided for the university as a whole, and the engineering faculty are committed to learning and engaging in these steps to provide a better Engineering Program and learning environment.

The Nancy Grace Roman Space Telescope Coronagraph Instrument is a critical technology demonstrator for NASA’s Habitable Worlds Observatory. With a predicted visible-light flux ratio detection limit of 10⁻⁸ or better, it will be capable of reaching new areas of parameter space for both gas giant exoplanets and circumstellar disks. It is in the final stages of integration and test at the Jet Propulsion Laboratory, with an anticipated delivery to payload integration in the coming year. This paper will review the instrument systems, observing modes, potential observing applications, and overall progress toward instrument integration and test.

The Nancy Grace Roman Space Telescope Coronagraph Instrument is a critical technology demonstrator for NASA's Habitable Worlds Observatory. With a predicted visible-light flux ratio detection limit of 1E-8 or better, it will be capable of reaching new areas of parameter space for both gas giant exoplanets and circumstellar disks. It is in the final stages of integration and test at the Jet Propulsion Laboratory, with an anticipated delivery to payload integration in the coming year. This paper will review the instrument systems, observing modes, potential observing applications, and overall progress toward instrument integration and test.

NASA is about to embark on an ambitious program to develop a Habitable Worlds Observatory (HWO) flagship mission to directly image approximately 25 potentially Earth-like planets and spectroscopically characterize them for signs of life, as recommended by the Astro2020 decadal survey. In addition, Astro2020 recommended a new approach for flagship formulation, which involves increasing the scope and depth of early, pre-phase A trades and technology maturation, as part of the new Great Observatories Maturation Program (GOMAP). The critical capability of the HWO mission is starlight suppression. To inform future architecture trades, it is necessary to survey a wide range of technologies, from the relatively mature ones such as the ones described in the LUVOIR and HabEx reports, to the relatively new and emerging ones, which may lead to breakthrough performance. In this paper, we present an interim update on a new effort, initiated by NASA’s Exoplanet Exploration Program (ExEP), to survey coronagraph design options for HWO. We present a preliminary summary of the survey, including: (1) a current list of coronagraph design options; (2) proposed evaluation criteria, such as expected mission yields and feasibility of maturing to TRL5 by 2029; and (3) tools and methods which we are using to quantify evaluations of different designs. While not charged to down-select or prioritize the different coronagraph designs, this survey is expected to be valuable in informing future mission teams of coronagraph design options. All interested coronagraph researchers are welcome to participate in this survey by contacting the first two authors of this paper.

Direct imaging of gas giant exoplanets provides information on their atmospheres and the architectures of planetary systems. However, few planets have been detected in blind surveys with direct imaging. Using astrometry from the Gaia and Hipparcos spacecraft, we identified dynamical evidence for a gas giant planet around the nearby star HIP 99770. We confirmed the detection of this planet with direct imaging using the Subaru Coronagraphic Extreme Adaptive Optics instrument. The planet, HIP 99770 b, orbits 17 astronomical units from its host star, receiving an amount of light similar to that reaching Jupiter. Its dynamical mass is 13.9 to 16.1 Jupiter masses. The planet-to-star mass ratio [(7 to 8) × 10 −3 ] is similar to that of other directly imaged planets. The planet’s atmospheric spectrum indicates an older, less cloudy analog of the previously imaged exoplanets around HR 8799.

Abstract Benchmark brown dwarf companions with well-determined ages and model-independent masses are powerful tools to test substellar evolutionary models and probe the formation of giant planets and brown dwarfs. Here, we report the independent discovery of HIP 21152 B, the first imaged brown dwarf companion in the Hyades, and conduct a comprehensive orbital and atmospheric characterization of the system. HIP 21152 was targeted in an ongoing high-contrast imaging campaign of stars exhibiting proper-motion changes between Hipparcos and Gaia, and was also recently identified by Bonavita et al. (2022) and Kuzuhara et al. (2022). Our Keck/NIRC2 and SCExAO/CHARIS imaging of HIP 21152 revealed a comoving companion at a separation of 0.″37 (16 au). We perform a joint orbit fit of all available relative astrometry and radial velocities together with the Hipparcos-Gaia proper motions, yielding a dynamical mass of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>24</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>6</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace width="0.25em"/> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>Jup</mml:mi> </mml:mrow> </mml:msub> </mml:math> , which is 1–2 σ lower than evolutionary model predictions. Hybrid grids that include the evolution of cloud properties best reproduce the dynamical mass. We also identify a comoving wide-separation (1837″ or 7.9 × 10 4 au) early-L dwarf with an inferred mass near the hydrogen-burning limit. Finally, we analyze the spectra and photometry of HIP 21152 B using the Saumon &amp; Marley (2008) atmospheric models and a suite of retrievals. The best-fit grid-based models have f sed = 2, indicating the presence of clouds, T eff = 1400 K, and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mi>g</mml:mi> <mml:mo>=</mml:mo> <mml:mn>4.5</mml:mn> <mml:mspace width="0.25em"/> <mml:mi>dex</mml:mi> </mml:math> . These results are consistent with the object’s spectral type of T0 ± 1. As the first benchmark brown dwarf companion in the Hyades, HIP 21152 B joins the small but growing number of substellar companions with well-determined ages and dynamical masses.