Schuyler Grace Wolff

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• Beichman, C., Bryden, G., Llop-Sayson, J., Ygouf, M., Greenbaum, A., Leisenring, J., Gaspar, A., Krist, J., Rieke, G., Wolff, S., Su, K., Hodapp, K., Meyer, M., Kelly, D., Boyer, M., Johnstone, D., Horner, S., & Rieke, M. (2025). Searching for Planets Orbiting Vega with the James Webb Space Telescope. Astronomical Journal, 169(Issue 1). doi:10.3847/1538-3881/ad890d
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  The most prominent of the IRAS debris disk systems, α Lyrae (Vega), at a distance of 7.7 pc, has been observed by both the NIRCam and MIRI instruments on the James Webb Space Telescope. This paper describes NIRCam coronagraphic observations, which have achieved F444W contrast levels of 3 × 10−7 at 1″ (7.7 au), 1 × 10−7 at 2″ (15 au), and a few × 10−8 beyond 5″ (38 au), corresponding to masses of
• Llop-Sayson, J., Beichman, C., Bryden, G., Ygouf, M., Gaspar, A., Thompson, W., Sanghi, A., Mawet, D., Meshkat, T., Greenbaum, A. Z., Leisenring, J., Wolff, S., Rieke, M., & Rieke, G. (2025). Searching for Planets Orbiting ϵ Eridani with JWST/NIRCam. Astronomical Journal, 170(Issue 4). doi:10.3847/1538-3881/adf727
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  We present observations of ϵ Eridani with the JWST/NIRCam coronagraph aimed at imaging planets orbiting within this system. In particular, these observations targeted (1) the Jupiter-like planet, first detected orbiting at 3.5 au with radial velocity observations, and (2) the planet postulated to be responsible for carving the edges of ϵ Eridani’s outer ring, expected to orbit at 40-50 au. However, no point sources were detected at a statistically significant level. We report new, improved upper limits at 4 μm: ∼1 × 10−6 contrast at 1″, and ∼2 × 10−8 beyond 5″. The latter contrast limit precludes Saturn-mass planets at separations >16 au given current models. We also report upper limits for ϵ Eridani’s disk emission at 4 μm. While the radial surface brightness profile shows no evidence of emission, we detect a 1σ surface brightness signal on the east side of the system, consistent with forward scattering emission expected for ϵ Eridani’s disk inclination. Finally, we evaluate the performance of the 3-roll observation strategy, which was first employed in these observations: the gains in contrast are modest, with 20%-30% improvements with respect to the conventional two-roll strategy.
• Ray, S., Sallum, S., Hinkley, S., Sivaramkrishnan, A., Cooper, R., Kammerer, J., Greebaum, A. Z., Thatte, D., Stolker, T., Lazzoni, C., Tokovinin, A., Furio, M. d., Factor, S., Meyer, M., Stone, J. M., Carter, A., Biller, B., Skemer, A., Suárez, G., , Leisenring, J. M., et al. (2025). The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. III. Aperture Masking Interferometric Observations of the Star HIP 65426 at 3.8 μm. Astrophysical Journal Letters, 983(Issue 1). doi:10.3847/2041-8213/adaeb7
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  We present aperture masking interferometry (AMI) observations of the star HIP 65426 at 3.8 μm, as part of the JWST Direct Imaging Early Release Science program, obtained using the Near Infrared Imager and Slitless Spectrograph instrument. This mode provides access to very small inner working angles (even separations slightly below the Michelson limit of 0.5λ/D for an interferometer), which are inaccessible with the classical inner working angles of the JWST coronagraphs. When combined with JWST’s unprecedented infrared sensitivity, this mode has the potential to probe a new portion of parameter space across a wide array of astronomical observations. Using this mode, we are able to achieve a 5σ contrast of ΔmF380M ∼ 7.62 ± 0.13 mag relative to the host star at separations ​​​​​≳0 . ″ 07, and the contrast deteriorates steeply at separations ≲0 . ″ 07. However, we detect no additional companions interior to the known companion HIP 65426b (at separation ∼0 . ″ 82 or 8 7 − 31 + 108 au ). Our observations thus rule out companions more massive than 10-12 MJup at separations ∼10-20 au from HIP 65426, a region out of reach of ground- or space-based coronagraphic imaging. These observations confirm that the AMI mode on JWST is sensitive to planetary mass companions at close-in separations (≳0 . ″ 07), even for thousands of more distant stars at ∼100 pc, in addition to the stars in the nearby young moving groups and associations, as stated in previous works. This result will allow the planning and successful execution of future observations to probe the inner regions of nearby stellar systems, opening an essentially unexplored parameter space.
• Tazaki, R., Ménard, F., Duchêne, G., Villenave, M., Ribas, Á., Stapelfeldt, K. R., Perrin, M. D., Pinte, C., Wolff, S. G., Padgett, D. L., Ma, J., Martinien, L., & Roumesy, M. (2025). JWST Imaging of Edge-on Protoplanetary Disks. IV. Mid-infrared Dust Scattering in the HH 30 Disk. Astrophysical Journal, 980(Issue 1). doi:10.3847/1538-4357/ad9c6f
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  We present near- and mid-infrared (IR) broadband imaging observations of the edge-on protoplanetary disk around HH 30 with the James Webb Space Telescope/Near Infrared Camera and the Mid-Infrared Instrument (MIRI). We combine these observations with archival optical/near-IR scattered light images obtained with the Hubble Space Telescope and a millimeter-wavelength dust continuum image obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) with the highest spatial resolution ever obtained for this target. Our multiwavelength images clearly reveal the vertical and radial segregation of micron-sized and submillimeter-sized grains in the disk. In the near- and mid-IR, the images capture not only bireflection nebulae separated by a dark lane but also diverse dynamical processes occurring in the HH 30 disk, such as spiral- and tail-like structures, a conical outflow, and a collimated jet. In contrast, the ALMA image reveals a flat dust disk in the disk midplane. By performing radiative transfer simulations, we show that grains of about 3 μm in radius or larger are fully vertically mixed to explain the observed mid-IR scattered light flux and its morphology, whereas millimeter-sized grains are settled into a layer with a scale height of ≳1 au at 100 au from the central star. We also find a tension in the disk inclination angle inferred from optical/near-IR and millimeter observations, with the latter being closer to exactly edge-on. Finally, we report the first detection of the proper motion of an emission knot associated with the mid-IR collimated jet detected by combining two epochs of our MIRI 12.8 μm observations.
• Wolff, S. G., Gáspár, A., Rieke, G., Leisenring, J. M., Sefilian, A. A., Ygouf, M., & Llop-Sayson, J. (2025). JWST/MIRI Imaging of the Warm Dust Component of the ϵ Eridani Debris Disk. Astronomical Journal, 170(Issue 4). doi:10.3847/1538-3881/adfcd6
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  We present JWST/MIRI observations of the debris disk surrounding the nearby solar analog ϵ Eridani obtained as part of the Archetypal Debris Disk Good Time Observation program. Multiwavelength images from 15, 18, 21, and 25.5 μm show a smooth dust distribution with no evidence of sculpting by massive planets outside of 5 au. Maps of the color temperature and opacity constrain the dust properties, while radiative transfer modeling of a warm dust component traces the interaction between the debris disk and ϵ Eridani b (∼3.5 au). Dynamical and collisional modeling further shows that the disk morphology is dominated by dust produced in the outer planetesimal belt (∼70 au) moving inward via stellar wind drag. We confirm the presence of a disk interior to the ϵ Eri b orbit first detected from mid-IR interferometry. Drag-dominated inner disk regions have also been observed around Vega and Fomalhaut, hinting at the diversity of asteroid belt analogs.
• Xie, C., Chen, C. H., Lisse, C. M., Hines, D. C., Beck, T., Betti, S. K., Pinilla-Alonso, N., Ingebretsen, C., Worthen, K., Gáspár, A., Wolff, S. G., Bolin, B. T., Pueyo, L., Perrin, M. D., Stansberry, J. A., & Leisenring, J. M. (2025). Water ice in the debris disk around HD 181327. Nature, 641(Issue 8063). doi:10.1038/s41586-025-08920-4
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  Debris disks are exoplanetary systems that contain planets, minor bodies (asteroids, Kuiper belt objects, comets and so on) and micrometre-sized debris dust1. Because water ice is the most common frozen volatile, it plays an essential role in the formation of planets2,3 and minor bodies. Although water ice has been commonly found in Kuiper belt objects and comets in the Solar System4, no definitive evidence for water ice in debris disks has been obtained to date1. Here we report the discovery of water ice in the HD 181327 debris disk using the near-infrared spectrograph onboard the James Webb Space Telescope. We detected the solid-state broad absorption feature of water ice at 3 µm including a distinct Fresnel peak at 3.1 µm, which is indicative of large, crystalline water-ice particles. Gradients in the water-ice feature as a function of stellocentric distance reveal a dynamic environment in which water ice is destroyed and replenished. We estimated the water-ice mass fractions as ranging from 0.1% at approximately 85 au to 21% at approximately 113 au, indicating the presence of a water-ice reservoir in the HD 181327 disk beyond the snow line. The icy bodies that release water ice in HD 181327 are probably the extra-solar counterparts of water-ice-rich Kuiper belt objects in our Solar System.
• Crotts, K. A., Crotts, K., Matthews, B. C., Matthews, B., Duchêne, G., Esposito, T., Espósito, T. M., Dong, R., Hom, J., Oppenheimer, R., Oppenheimer, B. R., Rice, M., Wolff, S., Chen, C., Ó, C. R., Kalas, P., Lewis, B., Lewis, B. C., Weinberger, A. J., , Weinberger, A., et al. (2024). A Uniform Analysis of Debris Disks with the Gemini Planet Imager. I. An Empirical Search for Perturbations from Planetary Companions in Polarized Light Images. Astrophysical Journal, 961(2). doi:10.3847/1538-4357/ad0e69
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  The Gemini Planet Imager (GPI) has excelled in imaging debris disks in the near-infrared. The GPI Exoplanet Survey imaged 24 debris disks in polarized H-band light, while other programs observed half of these disks in polarized J and/or K1 bands. Using these data, we present a uniform analysis of the morphology of each disk to find asymmetries suggestive of perturbations, particularly those due to planet-disk interactions. The multiwavelength surface brightness, disk color, and geometry permit the identification of any asymmetries such as warps or disk offsets from the central star. We find that 19 of the disks in this sample exhibit asymmetries in surface brightness, disk color, disk geometry, or a combination of the three, suggesting that for this sample, perturbations, as seen in scattered light, are common. The relationship between these perturbations and potential planets in the system is discussed. We also explore correlations among stellar temperatures, ages, disk properties, and observed perturbations. We find significant trends between the vertical aspect ratio and the stellar temperature, disk radial extent, and the dust grain size distribution power law, q. We also confirm a trend between the disk color and stellar effective temperature, where the disk becomes increasingly red/neutral with increasing temperature. Such results have important implications for the evolution of debris disk systems around stars of various spectral types.
• Cugno, G., Leisenring, J., Wagner, K., Mullin, C., Dong, R., Greene, T., Johnstone, D., Meyer, M., Wolff, S., Beichman, C., Boyer, M., Horner, S., Hodapp, K., Kelly, D., McCarthy, D., Roellig, T., Rieke, G., Rieke, M., Stansberry, J., & Young, E. (2024). JWST/NIRCam Imaging of Young Stellar Objects. II. Deep Constraints on Giant Planets and a Planet Candidate Outside of the Spiral Disk Around SAO 206462. Astronomical Journal, 167(4). doi:10.3847/1538-3881/ad1ffc
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  We present JWST/NIRCam F187N, F200W, F405N, and F410M direct imaging data of the disk surrounding SAO 206462. Previous images show a very structured disk, with a pair of spiral arms thought to be launched by one or more external perturbers. The spiral features are visible in three of the four filters, with the nondetection in F410M due to the large detector saturation radius. We detect with a signal-to-noise ratio of 4.4 a companion candidate that, if on a coplanar circular orbit, would orbit SAO 206462 at a separation of ∼300 au, 2.25σ away from the predicted separation for the driver of the eastern spiral. No other companion candidates were detected. At the location predicted by simulations of both spirals generated by a single massive companion, the NIRCam data exclude objects more massive than ∼2.2 M J assuming the BEX evolutionary models. In terms of temperatures, the data are sensitive to objects with T eff ∼ 650-850 K, when assuming planets emit like blackbodies (R p between 1 and 3R J). From these results, we conclude that if the spirals are driven by gas giants, these must be either cold or embedded in circumplanetary material. In addition, the NIRCam data provide tight constraints on ongoing accretion processes. In the low extinction scenario we are sensitive to mass accretion rates of the order M ̇ ∼ 10 − 9 M J yr−1. Thanks to the longer wavelengths used to search for emission lines, we reach unprecedented sensitivities to processes with M ̇ ∼ 10 − 7 M J yr−1 even toward highly extincted environments (A V ≈ 50 mag).
• Hom, J., Patience, J., Chen, C. H., Duchêne, G., Mazoyer, J., Millar-Blanchaer, M. A., Esposito, T. M., Kalas, P., Crotts, K. A., Gonzales, E. C., Kolokolova, L., Lewis, B. L., Matthews, B. C., Rice, M., Weinberger, A. J., Wilner, D. J., Wolff, S. G., Bruzzone, S., Choquet, E., , Debes, J., et al. (2024). A uniform analysis of debris discs with the Gemini Planet Imager II: constraints on dust density distribution using empirically informed scattering phase functions. Monthly Notices of the Royal Astronomical Society, 528(4), 6959-6984. doi:10.1093/mnras/stae368
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  Spatially resolved images of debris discs are necessary to determine disc morphological properties and the scattering phase function (SPF) thatantifies the brightness of scattered light as a function of phase angle. Current high-contrast imaging instruments have successfully resolved several dozens of debris discs around other stars, but few studies have investigated trends in the scattered-light, resolved population of debris discs in a uniform and consistent manner. We have combined Karhunen-Loeve Image Projection (KLIP) with radiative-transfer disc forward modelling in order to obtain the highest-quality image reductions and constrain disc morphological properties of eight debris discs imaged by the Gemini Planet Imager at H -band with a consistent and uniformly applied approach. In describing the scattering properties of our models, we assume a common SPF informed from solar system dust scattering measurements and apply it to all systems. We identify a diverse range of dust density properties among the sample, including critical radius, radial width, and vertical width. We also identify radially narrow and vertically extended discs that may have resulted from substellar companion perturbations, along with a tentative positive trend in disc eccentricity with relative disc width. We also find that using a common SPF can achieve reasonable model fits for discs that are axisymmetric and asymmetric when fitting models to each side of the disc independently, suggesting that scattering behaviour from debris discs may be similar to Solar system dust.
• Martinien, L., Tazaki, R., Perrin, M., Stapelfeldt, K., Pinte, C., Wolff, S., Grady, C., Dominik, C., Roumesy, M., Ma, J., Ginski, C., Benisty, M., Hines, D., Schneider, G., Duchêne, G., & Ménard, F. (2024). The grazing-angle icy protoplanetary disk PDS 453. Astronomy and Astrophysics, 692. doi:10.1051/0004-6361/202451475
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  Context. Observations of highly inclined protoplanetary disks provide a different point of view, in particular, they provide a more direct access to the vertical disk structure when compared to less steeply inclined more pole-on disks. Aims. PDS 453 is a rare highly inclined disk where the stellar photosphere is seen at grazing incidence on the disk surface. Our goal is take advantage of this geometry to constrain the structure and composition of this protoplanetary disk. In particular, it shows a 3.1 μm water-ice band in absorption that can be uniquely related to the disk. Methods. We observed the system in polarized intensity with the VLT/SPHERE instrument, as well as in polarized light and total intensity using the HST/NICMOS camera. Infrared archival photometry and a spectrum showing the water-ice band were used to model the spectral energy distribution under the Mie scattering theory. Based on these data, we fit a model using the radiative transfer code MCFOST to retrieve the geometry and dust and ice content of the disk. Results. PDS 453 has the typical morphology of a highly inclined system with two reflection nebulae in which the disk partially attenuates the stellar light. The upper nebula is brighter than the lower nebula and shows a curved surface brightness profile in polarized intensity. This indicates a ring-like structure. With an inclinationof 80° estimated from models, the line of sight crosses the disk surface, and a combination of absorption and scattering by ice-rich dust grains produces the water-ice band. Conclusions. PDS 453 is seen at high inclination and is composed of a mixture of silicate dust and water ice. The radial structure of the disk includes a significant jump in density and scale height at a radius of 70 au that produces a ring-like image. The depth of the 3.1 μm water-ice band depends on the amount of water ice, until it saturates when the optical thickness along the line of sight becomes too large. Therefore, quantifying the exact amount of water from absorption bands in edge-on disks requires a detailed analysis of the disk structure and tailored radiative transfer modeling. Further observations with JWST and ALMA will allow us to refine our understanding of the structure and content of this interesting system.
• Mullin, C., Dong, R., Leisenring, J., Cugno, G., Greene, T., Johnstone, D., Meyer, M., Wagner, K., Wolff, S., Boyer, M., Horner, S., Hodapp, K., McCarthy, D., Rieke, G., Rieke, M., & Young, E. (2024). JWST/NIRCam Imaging of Young Stellar Objects. III. Detailed Imaging of the Nebular Environment around the HL Tau Disk. Astronomical Journal, 167(4). doi:10.3847/1538-3881/ad2de9
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  As part of the James Webb Space Telescope (JWST) Guaranteed Time Observation program “Direct Imaging of YSOs” (program ID 1179), we use JWST NIRCam’s direct imaging mode in F187N, F200W, F405N, and F410M to perform high-contrast observations of the circumstellar structures surrounding the protostar HL Tau. The data reveal the known stellar envelope, outflow cavity, and streamers, but do not detect any companion candidates. We detect scattered light from an inflowing spiral streamer previously detected in HCO+ by the Atacama Large Millimeter/submillimeter Array, and part of the structure connected to the c-shaped outflow cavity. For detection limits in planet mass we use BEX evolutionary tracks when M p < 2 M J and AMES-COND evolutionary tracks otherwise, assuming a planet age of 1 Myr (youngest available age). Inside the disk region, due to extended envelope emission, our point-source sensitivities are ∼5 mJy (37 M J) at 40 au in F187N and ∼0.37 mJy (5.2 M J) at 140 au in F405N. Outside the disk region, the deepest limits we can reach are ∼0.01 mJy (0.75 M J) at a projected separation ∼ 525 au.
• Petrus, S., Whiteford, N., Patapis, P., Biller, B., Skemer, A., Hinkley, S., Palma-Bifani, P., Morley, C., Tremblin, P., Charnay, B., Vos, J., Wang, J., Stone, J., Bonnefoy, M., Chauvin, G., Miles, B., Carter, A., Lueber, A., Helling, C., , Sutlieff, B., et al. (2024). The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. V. Do Self-consistent Atmospheric Models Represent JWST Spectra? A Showcase with VHS 1256-1257 b. Astrophysical Journal Letters, 966(1). doi:10.3847/2041-8213/ad3e7c
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  The unprecedented medium-resolution (R λ ∼ 1500-3500) near- and mid-infrared (1-18 μm) spectrum provided by JWST for the young (140 ± 20 Myr) low-mass (12-20 M Jup) L-T transition (L7) companion VHS 1256 b gives access to a catalog of molecular absorptions. In this study, we present a comprehensive analysis of this data set utilizing a forward-modeling approach applying our Bayesian framework, ForMoSA. We explore five distinct atmospheric models to assess their performance in estimating key atmospheric parameters: T eff, log(g), [M/H], C/O, γ, f sed, and R. Our findings reveal that each parameter’s estimate is significantly influenced by factors such as the wavelength range considered and the model chosen for the fit. This is attributed to systematic errors in the models and their challenges in accurately replicating the complex atmospheric structure of VHS 1256 b, notably the complexity of its clouds and dust distribution. To propagate the impact of these systematic uncertainties on our atmospheric property estimates, we introduce innovative fitting methodologies based on independent fits performed on different spectral windows. We finally derived a T eff consistent with the spectral type of the target, considering its young age, which is confirmed by our estimate of log(g). Despite the exceptional data quality, attaining robust estimates for chemical abundances [M/H] and C/O, often employed as indicators of formation history, remains challenging. Nevertheless, the pioneering case of JWST’s data for VHS 1256 b has paved the way for future acquisitions of substellar spectra that will be systematically analyzed to directly compare the properties of these objects and correct the systematics in the models.
• Sallum, S., Ray, S., Kammerer, J., Sivaramakrishnan, A., Cooper, R., Greebaum, A., Thatte, D., De Furio, M., Factor, S., Meyer, M., Stone, J., Carter, A., Biller, B., Hinkley, S., Skemer, A., Leisenring, J., Perrin, M., Kraus, A., Absil, O., , Balmer, W., et al. (2024). The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. IV. NIRISS Aperture Masking Interferometry Performance and Lessons Learned. Astrophysical Journal Letters, 963(1). doi:10.3847/2041-8213/ad21fb
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  We present a performance analysis for the aperture masking interferometry (AMI) mode on board the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). Thanks to self-calibrating observables, AMI accesses inner working angles down to and even within the classical diffraction limit. The scientific potential of this mode has recently been demonstrated by the Early Release Science (ERS) 1386 program with a deep search for close-in companions in the HIP 65426 exoplanetary system. As part of ERS 1386, we use the same data set to explore the random, static, and calibration errors of NIRISS AMI observables. We compare the observed noise properties and achievable contrast to theoretical predictions. We explore possible sources of calibration errors and show that differences in charge migration between the observations of HIP 65426 and point-spread function calibration stars can account for the achieved contrast curves. Lastly, we use self-calibration tests to demonstrate that with adequate calibration NIRISS F380M AMI can reach contrast levels of ~9-10 mag at ≥λ/D. These tests lead us to observation planning recommendations and strongly motivate future studies aimed at producing sophisticated calibration strategies taking these systematic effects into account. This will unlock the unprecedented capabilities of JWST/NIRISS AMI, with sensitivity to significantly colder, lower-mass exoplanets than lower-contrast ground-based AMI setups, at orbital separations inaccessible to JWST coronagraphy.
• Stapelfeldt, K., Villenave, M., Wolff, S., Perrin, M., Pinte, C., Tazaki, R., Padgett, D., Duchêne, G., & Ménard, F. (2024). JWST Imaging of Edge-on Protoplanetary Disks. I. Fully Vertically Mixed 10 μm Grains in the Outer Regions of a 1000 au Disk. Astronomical Journal, 167(2). doi:10.3847/1538-3881/acf9a7
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  Scattered light imaging of protoplanetary disks provides key insights on the geometry and dust properties in the disk surface. Here, we present James Webb Space Telescope (JWST) 2-21 μm images of a 1000 au radius edge-on protoplanetary disk surrounding an 0.4 M ⊙ young star in Taurus, Two Micron All Sky Survey (2MASS) J04202144 + 2813491. These observations represent the longest wavelengths at which a protoplanetary disk is spatially resolved in scattered light. We combine these observations with Hubble Space Telescope optical images and Atacama Large Millimeter/submillimeter Array continuum and CO mapping. We find that the changes in the scattered light disk morphology are remarkably small across a factor of 30 in wavelength, indicating that dust in the disk surface layers is characterized by an almost gray opacity law. Using radiative transfer models, we conclude that grains up to ≳10 μm in size are fully coupled to the gas in this system, whereas grains ≳100 μm are strongly settled toward the midplane. Further analyses of these observations, and similar ones of other edge-on disks, will provide strong empirical constraints on disk dynamics and evolution and grain growth models. In addition, the 7.7 and 12. μm JWST images reveal an X-shaped feature located above the warm molecular layer traced by CO line emission. The highest elevations at which this feature is detectable roughly match the maximal extent of the disk in visible wavelength scattered light as well as of an unusual kinematic signature in CO. We propose that these phenomena could be related to a disk wind entraining small dust grains.
• Su, K. Y., Gáspár, A., Rieke, G. H., Malhotra, R., Matrá, L., Wolff, S. G., Leisenring, J. M., Beichman, C., & Ygouf, M. (2024). Imaging of the Vega Debris System Using JWST/MIRI. Astrophysical Journal, 977(Issue 2). doi:10.3847/1538-4357/ad8cde
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  We present images of the Vega planetary debris disk obtained at 15.5, 23, and 25.5 μm with the Mid-Infrared Instrument on JWST. The debris system is remarkably symmetric, smooth, and centered accurately on the star. There is a broad Kuiper-belt-analog ring at ∼80-170 au that coincides with the planetesimal belt detected with the Atacama Large Millimeter/submillimeter Array at 1.34 mm. The interior of the broad belt is filled with warm debris that shines most efficiently at mid-infrared, along with a shallow flux dip/gap at 60 au from the star. These qualitative characteristics argue against any Saturn-mass planets orbiting the star outside of about 10 au, assuming the unseen planet would be embedded in the very broad planetesimal disk from a few to hundreds of astronomical units. We find that the distribution of dust detected interior to the broad outer belt is consistent with grains being dragged inward by the Poynting-Robertson effect. Under the drag-dominated disk assumption, tighter constraints can be derived for planets in specific locations; for example, any planet shepherding the inner edge of the outer belt is likely to be less than six Earth masses. The disk surface brightness profile along with the available infrared photometry suggest a disk inner edge near ∼3−5 au, disconnected from the sub-astronomical-unit region that gives rise to the hot near-infrared excess. The gap between the hot, sub-astronomical-unit zone and the inner edge of the warm debris might be shepherded by a modest-mass, Neptune-size planet.
• Villenave, M., Stapelfeldt, K., Perrin, M., Pinte, C., Wolff, S., Tazaki, R., Padgett, D., Duchêne, G., & Ménard, F. (2024). JWST Imaging of Edge-on Protoplanetary Disks. III. Drastic Morphological Transformation Across the Mid-infrared in Oph163131. Astrophysical Journal, 975(2). doi:10.3847/1538-4357/ad7de0
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  We present JWST broadband images of the highly inclined protoplanetary disk SSTc2d J163131.2-242627 (Oph163131) from 2.0 to 21 μm. The images show a remarkable evolution in disk structure with wavelength, quite different from previous JWST observations of other edge-on disks. At 2.0 and 4.4 μm, Oph163131 shows two scattering surfaces separated by a dark lane, typical of highly inclined disks. Starting at 7.7 μm, however, (1) the two linear nebulosities flanking the dark lane disappear; (2) the brighter nebula tracing the disk upper surface transitions into a compact central source distinctly larger than the JWST point-spread function and whose intrinsic size increases with wavelength; and (3) patches of extended emission appear at low latitudes, and at surprisingly large radii nearly twice that of the scattered light seen with Hubble Space Telescope and NIRCam, and of the gas. We interpret the compact central source as thermal emission from the star and the inner disk that is not seen directly, but which instead is able to progressively propagate to greater distances at longer wavelengths. The lack of sharp-edged structures in the extended patchy emission argues against the presence of shocks and suggests photoexcitation or stochastic heating of material smoothly flowing away from the star along the disk surface. Finally, the dark lane thickness decreases significantly between 0.6 and 4.4 μm, which indicates that the surface layers of Oph163131 lack grains larger than 1 μm.
• Villenave, M., Stapelfeldt, K., Wolff, S., Perrin, M., Pinte, C., Tazaki, R., Padgett, D., Duchêne, G., & Ménard, F. (2024). JWST Imaging of Edge-on Protoplanetary Disks. II. Appearance of Edge-on Disks with a Tilted Inner Region: Case Study of IRAS04302+2247. Astrophysical Journal, 961(1). doi:10.3847/1538-4357/ad0c4b
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  We present James Webb Space Telescope imaging from 2 to 21 μm of the edge-on protoplanetary disk around the embedded young star IRAS04302+2247. The structure of the source shows two reflection nebulae separated by a dark lane. The source extent is dominated by the extended filamentary envelope at ∼4.4 μm and shorter wavelengths, transitioning at 7.7 μm and longer wavelengths to more compact lobes of scattered light from the disk itself. The dark lane thickness does not vary significantly with wavelength, which we interpret as an indication for intermediate-sized (∼10 μm) grains in the upper layers of the disk. Intriguingly, we find that the brightest nebula of IRAS40302 switches side between 12.8 and 21 μm. We explore the effect of a tilted inner region on the general appearance of edge-on disks. We find that radiative transfer models of a disk including a tilted inner region can reproduce an inversion in the brightest nebula. In addition, for specific orientations, the model predicts strong lateral asymmetries, which can occur for more than half possible viewing azimuths. A large number of edge-on protoplanetary disks observed in scattered light show such lateral asymmetries (15/20), which suggests that a large fraction of protoplanetary disks might host a tilted inner region. Stellar spots may also induce lateral asymmetries, which are expected to vary over a significantly shorter timescale. Variability studies of edge-on disks would allow us to test the dominant scenario for the origin of these asymmetries.
• Wagner, K., Leisenring, J., Cugno, G., Mullin, C., Dong, R., Wolff, S., Greene, T., Johnstone, D., Meyer, M., Beichman, C., Boyer, M., Horner, S., Hodapp, K., Kelly, D., McCarthy, D., Roellig, T., Rieke, G., Rieke, M., Sitko, M., , Stansberry, J., et al. (2024). JWST/NIRCam Imaging of Young Stellar Objects. I. Constraints on Planets Exterior to the Spiral Disk Around MWC 758. Astronomical Journal, 167(4). doi:10.3847/1538-3881/ad11d5
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  MWC 758 is a young star hosting a spiral protoplanetary disk. The spirals are likely companion-driven, and two previously identified candidate companions have been identified—one at the end the Southern spiral arm at ∼0.″6, and one interior to the gap at ∼0.″1. With JWST/NIRCam, we provide new images of the disk and constraints on planets exterior to ∼1″. We detect the two-armed spiral disk, a known background star, and a spatially resolved background galaxy, but no clear companions. The candidates that have been reported are at separations that are not probed by our data with sensitivity sufficient to detect them−nevertheless, these observations place new limits on companions down to ∼2 M Jup at ∼150 au and ∼0.5 M Jup at ≳600 au. Owing to the unprecedented sensitivity of JWST and youth of the target, these are among the deepest mass-detection limits yet obtained through direct imaging observations, and provide new insights into the system’s dynamical nature.
• Wolff, S., Rieke, G., Leisenring, J., Su, K., Wilner, D., Ygouf, M., Ballering, N., Gáspár, A., & Matrà, L. (2024). Deep Search for a Scattered Light Dust Halo Around Vega with the Hubble Space Telescope. Astronomical Journal, 168(6). doi:10.3847/1538-3881/ad67cb
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  We present a provisory scattered-light detection of the Vega debris disk using deep Hubble Space Telescope (HST) coronagraphy (PID 16666). At only 7.7 pc, Vega is immensely important in debris disk studies both for its prominence and also because it allows the highest physical resolution among all debris systems relative to temperature zones around the star. We employ the STIS coronagraph's widest wedge position and classical reference differential imaging to achieve among the lowest surface-brightness sensitivities to date (∼4 mJy arcsec-2 ) at wide separations using 32 orbits in Cycle 29. We detect a halo extending from the inner edge of our effective inner working angle at 10 5 out to the photon noise floor at 30' (80-230 au). The face-on orientation of the system and the lack of a perfectly color-matched point-spread function star have posed significant challenges to the reductions, particularly regarding artifacts from the imperfect color matching. However, we find that a halo of small dust grains provides the best explanation for the observed signal. Unlike Fomalhaut (a close twin to Vega in luminosity, distance, and age), there is no clear distinction in scattered light between the parent planetesimal belt observed with the Atacama Large Millimeter/submillimeter Array and the extended dust halo. These HST observations complement JWST GTO Cycle 1 observations of the system with NIRCam and MIRI.
• Ygouf, M., Beichman, C., Llop-Sayson, J., Bryden, G., Leisenring, J., Krist, J., Rieke, M., Rieke, G., Wolff, S., Roellig, T., Su, K., Hainline, K., Hodapp, K., Greene, T., Meyer, M., Kelly, D., Misselt, K., Stansberry, J., Boyer, M., , Johnstone, D., et al. (2024). Searching for Planets Orbiting Fomalhaut with JWST/NIRCam. Astronomical Journal, 167(1). doi:10.3847/1538-3881/ad08c8
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  We report observations with the JWST/NIRCam coronagraph of the Fomalhaut (α PsA) system. This nearby A star hosts a complex debris disk system discovered by the IRAS satellite. Observations in F444W and F356W filters using the round 430R mask achieve a contrast ratio of ∼4 × 10−7 at 1″ and ∼4 × 10−8 outside of 3″. These observations reach a sensitivity limit of 0.7 mag (Vega) color. Whether this object is a background galaxy, brown dwarf, or a Jovian-mass planet in the Fomalhaut system will be determined by an approved Cycle 2 follow-up program. Finally, we set upper limits to any scattered light from the outer ring, placing a weak limit on the dust albedo at F356W and F444W.

Proceedings Publications

• Anche, R., Milani, K., Doelman, D., Hom, J., Millar-Blanchaer, M., Wolff, S., Douglas, E., Snik, F., & Ashcraft, J. (2024). High-contrast polarimetric observations of debris disks through the Roman Coronagraph Instrument. In Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave, 13092.
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  Polarimetric differential i maging o bservations p rovide t he h ighest c ontrast i mages o f c ircumstellar d isks i n addition to providing information on dust grain scattering properties. The upcoming Nancy Grace Roman Space Telescope Coronagraph is expected to measure the linear polarization fraction of disks greater than 0.3 with an uncertainty of 0.03. One of the critical problems with polarimetric observations is the polarization aberrations generated by the telescope and polarimetric optics, which introduce errors when measuring lower SNR polarized signals. A modeling pipeline was previously developed to simulate the polarization observations of higher SNR debris disks similar without accounting for polarization aberrations. Here, we present the simulated polarimetric disk images of fainter debris disks (∼0.1mJy/arcsec2) through the Roman telescope and the HLC and SPC coronagraphs, incorporating polarization aberrations, jitter, detector, and speckle noise. The Point Response Functions are generated using PROPER for each orthogonal polarization state to account for the polarization aberrations. Finally, we compare the recovered polarization fraction of the debris disk with the input to demonstrate the polarimetric capability of the Roman Coronagraph.
• Savransky, D., Bailey, V., Wolff, S., Millar-Blanchaer, M., Wang, J., Altinier, L., Anche, R., Baudoz, P., Biller, B., Blunt, S., Brandner, W., Brinjikji, M., Chavez, A., Choquet, E., Doelman, D., Girard, J., Greenbaum, A., Hasler, S., Hom, J., , Ingalls, J., et al. (2024). The Nancy Grace Roman Space Telescope Coronagraph Community Participation Program. In Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave, 13092.
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  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.
• Wolff, S., Wang, J., Stapelfeldt, K., Bailey, V., Savransky, D., Hom, J., Biller, B., Brandner, W., Anche, R., Blunt, S., Brinjikji, M., Girard, J., Krause, O., Li, Z., Livingston, J., Millar-Blanchaer, M., Noel, M., Pueyo, L., De Rosa, R., , Samland, M., et al. (2024). The Roman Coronagraph Community Participation Program: observation planning. In Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave, 13092.
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  The Coronagraph Instrument onboard the Nancy Grace Roman Space Telescope is an important stepping stone towards the characterization of habitable, rocky exoplanets. In a Observation Phase conducted during the first 18 months of the mission (expected to launch in late 2026), novel starlight suppression technology may enable direct imaging of a Jupiter analog in reflected light. Here we summarize the current activities of the Observation Planning working group formed as part of the Community Participation Program. This working group is responsible for target selection and observation planning of both science and calibration targets in the technology demonstration phase of the Roman Coronagraph. We will discuss the ongoing efforts to expand target and reference catalogs, and to model astrophysical targets (exoplanets and circumstellar disks) within the Coronagraph’s expected sensitivity. We will also present preparatory observations of high priority targets.