VLT/SPHERE Multiwavelength High-contrast Imaging of the HD 115600 Debris Disk: New Constraints on the Dust Geometry and the Presence of Young Giant Planets

Young and dynamically active planetary systems can form disks of debris that are easier to image than the planets themselves. The morphology and evolution of these disks can help to infer the properties of the putative planets responsible for generating and shaping the debris structures. We present integral field spectroscopy and dual-band imaging from VLT/SPHERE (1.0─1.7 μm) of the debris disk around the young F2V/F3V star HD 115600. We aim to (1) characterize the geometry and composition of the debris ring, (2) search for thermal emission of young giant planets, and (3) in the absence of detected planets, to refine the inferred properties of plausible planets around HD 115600 to prepare future attempts to detect them. Using a different dust scattering model (ZODIPIC) than in the discovery paper to model the disk geometry, we find a 0 = 46 ± 2 au for the disk’s central radius and offsets ∆α, ∆δ = −1.0 ± 0.5, 0.5 ± 0.5 au. This offset is smaller than previously found, suggesting that unseen planets of lower masses could be sculpting the disk. Spectroscopy of the disk in Y-J bands with SPHERE shows reddish color, which becomes neutral or slightly blue in H-band seen with GPI, broadly consistent with a mixed bulk disk composition of processed organics and water ice. While our observed field contains numerous background objects at wide separations, no exoplanet has been directly observed to a mass sensitivity limit of 2 − 3(5 − 7) M J between a projected separation of 40 and 200 au for hot (cold)-start models

Gemini Planet Imager observational calibrations XV: instrument calibrations after six years on sky

The Gemini Planet Imager (GPI) is a high-contrast adaptive optics instrument designed to detect and characterize substellar companions and circumstellar debris disks around nearby young stars using infrared integral field spectroscopy and polarimetry. GPI has been in routine operations at Gemini South for the past six years. Because precise astrometry and photometry of exoplanets is critical to GPI's science, we undertook extensive efforts both in-lab and on-sky to refine the astrometric and photometric calibration of the instrument. We describe revisions to the GPI Data Reduction Pipeline (DRP) that account for these revised calibrations, and that fix several issues identified over the previous six years, including some subtle issues affecting astrometric calibrations caused by a drift of the instrument’s clock. These calibrations are critical for the interpretation of observations obtained with GPI, and for a comparison with measurements from other high-contrast imaging instruments

Gemini Planet Imager observational calibrations XV: instrument calibrations after six years on sky

The Gemini Planet Imager (GPI) is a high-contrast adaptive optics instrument designed to detect and characterize substellar companions and circumstellar debris disks around nearby young stars using infrared integral field spectroscopy and polarimetry. GPI has been in routine operations at Gemini South for the past six years. Because precise astrometry and photometry of exoplanets is critical to GPI's science, we undertook extensive efforts both in-lab and on-sky to refine the astrometric and photometric calibration of the instrument. We describe revisions to the GPI Data Reduction Pipeline (DRP) that account for these revised calibrations, and that fix several issues identified over the previous six years, including some subtle issues affecting astrometric calibrations caused by a drift of the instrument’s clock. These calibrations are critical for the interpretation of observations obtained with GPI, and for a comparison with measurements from other high-contrast imaging instruments

Surveying Nearby Brown Dwarfs with HGCA: Direct Imaging Discovery of a Faint, High-Mass Brown Dwarf Orbiting HD 176535 A

Brown dwarfs with well-measured masses, ages and luminosities provide direct benchmark tests of substellar formation and evolutionary models. We report the first results from a direct imaging survey aiming to find and characterize substellar companions to nearby accelerating stars with the assistance of the Hipparcos-Gaia Catalog of Accelerations (HGCA). In this paper, we present a joint high-contrast imaging and astrometric discovery of a substellar companion to HD 176535 A, a K3.5V main-sequence star aged approximately $3.59_{-1.15}^{+0.87}$ Gyrs at a distance of $36.99 \pm 0.03$ pc. In advance of our high-contrast imaging observations, we combined precision HARPS RVs and HGCA astrometry to predict the potential companion's location and mass. We thereafter acquired two nights of KeckAO/NIRC2 direct imaging observations in the $L'$ band, which revealed a companion with a contrast of $\Delta L'_p = 9.20\pm0.06$ mag at a projected separation of $\approx$0.\!\!''35 ($\approx$13 AU) from the host star. We revise our orbital fit by incorporating our dual-epoch relative astrometry using the open-source MCMC orbit fitting code $\tt orvara$. HD 176535 B is a new benchmark dwarf useful for constraining the evolutionary and atmospheric models of high-mass brown dwarfs. We found a luminosity of $\rm log(L_{bol}/L_{\odot}) = -5.26\pm0.06$ and a model-dependent effective temperature of $980 \pm 35$ K for HD 176535 B. Our dynamical mass suggests that some substellar evolutionary models may be underestimating luminosity for high-mass T dwarfs. Given its angular separation and luminosity, HD 176535 B would make a promising candidate for Aperture Masking Interferometry with JWST and GRAVITY/KPIC, and further spectroscopic characterization with instruments like the CHARIS/SCExAO/Subaru integral field spectrograph

EDEN Survey: Small Transiting Planet Detection Limits and Constraints on the Occurrence Rates for Late M Dwarfs within 15 pc

Earth-sized exoplanets that transit nearby, late spectral type red dwarfs will be prime targets for atmospheric characterization in the coming decade. Such systems, however, are difficult to find via wide-field transit surveys like Kepler or TESS. Consequently, the presence of such transiting planets is unexplored and the occurrence rates of short-period Earth-sized planets around late M dwarfs remain poorly constrained. Here, we present the deepest photometric monitoring campaign of 22 nearby late M dwarf stars, using data from over 500 nights on seven 1-2 meter class telescopes. Our survey includes all known single quiescent northern late M dwarfs within 15 pc. We use transit-injection-and-recovery tests to quantify the completeness of our survey, successfully identify most ($>80\%$) transiting short-period (0.5-1 d) super-Earths ($R > 1.9 R_\oplus$), and are sensitive ($\sim50\%$) to transiting Earth-sized planets ($1.0-1.2 R_\oplus$). Our high sensitivity to transits with a near-zero false positive rate demonstrates an efficient survey strategy. Our survey does not yield a transiting planet detection, yet it provides the most sensitive upper limits on transiting planets orbiting our target stars. Finally, we explore multiple hypotheses about the occurrence rates of short-period planets (from Earth-sized planets to giant planets) around late M dwarfs. We show, for example, that giant planets at short periods ($<1$ day) are uncommon around our target stars. Our dataset provides some insight into occurrence rates of short-period planets around TRAPPIST-1-like stars, and our results can help test planetary formation and system evolution models, as well as guide future observations of nearby late M dwarfs.Comment: 27 pages, 11 figure

The development of HISPEC for Keck and MODHIS for TMT: science cases and predicted sensitivities

HISPEC is a new, high-resolution near-infrared spectrograph being designed for the W.M. Keck II telescope. By offering single-shot, R=100,000 between 0.98 - 2.5 um, HISPEC will enable spectroscopy of transiting and non-transiting exoplanets in close orbits, direct high-contrast detection and spectroscopy of spatially separated substellar companions, and exoplanet dynamical mass and orbit measurements using precision radial velocity monitoring calibrated with a suite of state-of-the-art absolute and relative wavelength references. MODHIS is the counterpart to HISPEC for the Thirty Meter Telescope and is being developed in parallel with similar scientific goals. In this proceeding, we provide a brief overview of the current design of both instruments, and the requirements for the two spectrographs as guided by the scientific goals for each. We then outline the current science case for HISPEC and MODHIS, with focuses on the science enabled for exoplanet discovery and characterization. We also provide updated sensitivity curves for both instruments, in terms of both signal-to-noise ratio and predicted radial velocity precision.Comment: 25 pages, 9 figures. To appear in the Proceedings of SPIE: Techniques and Instrumentation for Detection of Exoplanets XI, vol. 12680 (2023

Managing Infrastructural and Service Demands in New Economic Spaces: The New Territorial Politics of Collective Provision

Jonas A. E. G., While A. H. and Gibbs D. C. Managing infrastructural and service demands in new economic spaces: the new territorial politics of collective provision, Regional Studies. Research on the geography of urban and regional economic development in the United States and Europe often emphasizes the contribution of supply-side entrepreneurial local policies to the development and competitiveness of new economic spaces (NES) in and around city-regions. Such policies include public-private partnerships and new forms of regional governance. As hitherto successful NES mature, a newer set of struggles has emerged in particular cities and regions having important clusters of new economic activities. These involve new demands for collective provision of infrastructure, workforce housing, and services. Using evidence from Greater Boston in Massachusetts, United States, and the Cambridge city-region in the UK, the paper proposes a set of concepts with which to investigate the new territorial politics of collective provision. This politics is an increasingly significant yet under-theorized aspect of the social regulation and competitiveness of NES. [image omitted] Jonas A. E. G., While A. H. et Gibbs D. C. Maitriser la demande d'equipement et de services dans les nouvelles espaces economiques: la nouvelle politique territoriale visant la prestation collective, Regional Studies. La recherche sur la geographie du developpement economique urbano-regional aux Etats-Unis et en Europe souligne souvent la contribution des politiques locales entrepreneuriales de l'offre au developpement et a la competitivite des nouvelles espaces economiques au sein et autour des cites-regions. De telles politiques incluent des partenariats publics-prives et de nouvelles formes de gouvernance regionale. Au fur et a mesure que les nouvelles espaces economiques reussies murissent, un nouvel ensemble de conflits a fait le jour dans certaines grandes villes et regions qui ont d'importantes grappes de nouvelles activites economiques. Celles-la comportent de nouvelles demandes de prestation d'equipement, de logement social et de services collective. A partir des donnees pour Greater Boston, aux E-U, et pour la cite-region de Cambridge, au R-U, cet article propose un ensemble de concepts a l'aide duquel on peut examiner la nouvelle politique territoriale de prestation collective. Cette politique est un aspect de plus en plus important, pourtant insuffisamment theorise, de la reglementation sociale et de la competitivite des nouvelles espaces economiques. Nouvelles espaces economiques Prestation collective Etat Etats-Unis Europe Jonas A. E. G., While A. H. und Gibbs D. C. Verwaltung der Nachfrage nach Infrastruktur und Dienstleistungen in neuen Wirtschaftsraumen: die neue Territorialpolitik der kollektiven Beschaffung, Regional Studies. Bei der Erforschung der Geografie der urbanen und regionalen Wirtschaftsentwicklung in den USA und Europa wird oft der Beitrag der lokalen Unternehmenspolitik auf der Angebotsseite zur Entwicklung und Wettbewerbsfahigkeit von neuen Wirtschaftsraumen in Stadtregionen und ihrer Umgebung betont. Beispiele hierfur sind offentlich-private Partnerschaften und neue Formen der Regionalregierung. Wahrend bisher erfolgreiche neue Wirtschaftsraume reifen, haben sich in bestimmten Stadten und Regionen, die uber wichtige Cluster neuer Wirtschaftstatigkeiten verfugen, neuere Arten von Bemuhungen herausgebildet. Hierzu gehort eine neue Nachfrage nach einer kollektiven Bereitstellung von Infrastruktur, Arbeitnehmer-Unterkunften und Dienstleistungen. Anhand von Belegen aus dem Grossraum Boston in den USA sowie aus der Stadtregion Cambridge in Grossbritannien schlagen wir in diesem Beitrag verschiedene Konzepte zur Untersuchung der neuen Territorialpolitik kollektiver Beschaffung vor. Diese Politik stellt einen immer wichtigeren, aber zu wenig theoretisierten Aspekt der gesellschaftlichen Regelung und Wettbewerbsfahigkeit von neuen Wirtschaftsraumen dar. Neue Wirtschaftsraume Kollektive Beschaffung Staat USA Europa Jonas A. E. G., While A. H. y Gibbs D. C. Gestion de las demandas de infraestructura y servicios en los nuevos espacios economicos: las nuevas politicas territoriales de dotacion colectiva, Regional Studies. En el estudio sobre geografia del desarrollo economico urbano y regional en los Estados Unidos y Europa se suele recalcar la contribucion de las politicas locales empresariales de suministro para el desarrollo y la competitividad de los nuevos espacios economicos en las regiones metropolitanas y alrededores. Estas politicas incluyen sociedades publicas-privadas y nuevas formas de gobierno regional. Mientras maduran los nuevos espacios economicos, hasta ahora con gran exito, se han desarrollado nuevos esfuerzos en determinadas ciudades y regiones que disponen de importantes aglomeraciones de nuevas actividades economicas. Esto implica nuevas demandas de una dotacion colectiva de infraestructura, viviendas para los trabajadores y servicios. Mediante los ejemplos del Greater Boston en los Estados Unidos y la region metropolitana de Cambridge en el Reino Unido, en este articulo proponemos una serie de conceptos con los que analizamos las nuevas politicas territoriales de dotacion colectiva. Estas politicas representan un aspecto cada vez mas importante, aunque todavia poco teorizado, de la regulacion social y la competitividad de los nuevos espacios economicos. Nuevos espacios economicos Dotacion colectiva El Estado EE.UU EuropaNew economic spaces, Collective provision, The state, USA, Europe,

The new urban politics as a politics of carbon control

The new urban politics (NUP) literature has helped to draw attention to a new generation of entrepreneurial urban regimes involved in the competition to attract investment to cities. Interurban competition often had negative environmental consequences for the urban living place. Yet knowledge of the environment was not very central to understanding the NUP. Entrepreneurial urban regimes today are struggling to deal with climate change and reductions in greenhouse gas emissions. Carbon reduction strategies could have profound implications for interurban competition and the politics of urban development. This paper explores the rise of a distinctive low-carbon urban polity-carbon control-and examines its potential ramifications for a new environmental politics of urban development (NEPUD). The NEPUD signals the growing centrality of carbon control in discourses, strategies and struggles around urban development. Using examples from cities in the US and Europe, the paper examines how these new environmental policy considerations are being mainstreamed in urban development politics. Alongside competitiveness, the management of carbon emissions represents a new yet at the same time contestable mode of calculation in urban governance