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9 results on '"Lynne Hillenbrand"'

1. An Expanding Accretion Disk and a Warm Disk Wind as Seen in the Spectral Evolution of HBC 722

Author

Adolfo Carvalho, Lynne Hillenbrand, Jerome Seebeck, and Kevin Covey

Subjects
FU Orionis stars, Young stellar objects, Infrared sources, Stellar accretion disks, Pre-main sequence stars, Optical bursts, Astrophysics, QB460-466
Abstract

We present a comprehensive analysis of the post-outburst evolution of the FU Ori object HBC 722 in optical/near-infrared (NIR) photometry and spectroscopy. Using a modified viscous accretion disk model, we fit the outburst epoch spectral energy distribution to determine the physical parameters of the disk, including ${\dot{M}}_{\mathrm{acc}}={10}^{-4.0}\ {M}_{\odot }$ yr ^−1 , R _inner = 3.65 R _⊙ , i = 79°, and a maximum disk temperature of ${T}_{\max }=5700$ K. We then use a decade of optical/NIR spectra to demonstrate a changing accretion rate drives the visible-range photometric variation, while the NIR shows the outer radius of the active accretion disk expands outward as the outburst progresses. We also identify the major components of the disk system: a plane-parallel disk atmosphere in Keplerian rotation and a two-part warm disk wind that is collimated near the star and wide-angle at larger radii. The wind is traced by classic wind lines, and appears as a narrow, low-velocity, deep absorption component in several atomic lines spanning the visible spectrum and in the CO 2.29 μ m band. We compare the wind lines to those computed from wind models for other FU Ori systems and rapidly accreting young stellar disks and find a 4000–6000 K wind can explain the observed line profiles. Fitting the progenitor spectrum, we find M _* = 0.2 M _⊙ and ${\dot{M}}_{\mathrm{progenitor}}=7.8\times {10}^{-8}\ {M}_{\odot }\ {\mathrm{yr}}^{-1}$ . Finally, we discuss HBC 722 relative to V960 Mon, another FU Ori object we have previously studied in detail.

Published
2024
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2. Disk Cooling and Wind Lines as Seen in the Spectral Line Evolution of V960 Mon

Author

Adolfo Carvalho, Lynne Hillenbrand, and Jerome Seebeck

Subjects
FU Orionis stars, Stellar accretion disks, High resolution spectroscopy, Young stellar objects, Stellar winds, Optical bursts, Astrophysics, QB460-466
Abstract

We follow up our photometric study of the postoutburst evolution of the FU Ori object V960 Mon with a complementary spectroscopic study at high dispersion that uses time series spectra from the Keck/HIgh Resolution Echelle Spectrograph. Consistent with the photometric results reported in Carvalho et al., we find that the spectral evolution of V960 Mon corresponds to a decrease in the temperature of the inner disk, driven by a combination of a decreasing accretion rate and an increasing inner disk radius. We also find that although the majority of the absorption lines are well matched by our accretion disk model spectrum, there are several strong absorption line families and a few emission lines that are not captured by the model. By subtracting the accretion disk model from the data at each epoch, we isolate the wind and outflow components of the system. The residuals show both broad and highly blueshifted profiles, as well as narrow and only slightly blueshifted profiles, with some lines displaying both types of features.

Published
2023
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3. Closing gaps to our origins: EUVO: the ultraviolet-visible window into the Universe

Author

Ana I Gómez de Castro, Martin A. Barstow, Frederic Baudin, Stefano Benetti, Jean Claude Bouret, Noah Brosch, Ada Canet, Domitilla de Martino, Giulio del Zanna, Chris Evans, Kevin France, Miriam García, Boris Gaensicke, Lynne Hillenbrand, Eric Josselin, Carolina Kehrig, Laurent Lamy, Jon Lapington, Alain Lecavelier des Etangs, Giampiero Naletto, Yael Nazé, Coralie Neiner, Jonathan Nichols, Marina Orio, Isabella Pagano, Céline Peroux, Gregor Rauw, Steven Shore, Gagik Tovmassian, Asif ud-Doula, Ministerio de Ciencia e Innovación (España), CSIC - Unidad de Recursos de Información Científica para la Investigación (URICI), Gómez de Castro, AI [0000-0002-3598-9643], Apollo - University of Cambridge Repository, and ESP

Subjects
stars, Ultraviolet, general, galaxies, ISM, solar system, Instrumentation, miscellaneous, telescopes, Ultraviolet: ISM, Astronomy and Astrophysics, Ultraviolet: solar system, Ultraviolet: stars, Instrumentation: telescopes, Space and Planetary Science, Ultraviolet: galaxies, Ultraviolet: general, Instrumentation: miscellaneous, QB
Abstract

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visithttp://creativecommons.org/licenses/by/4.0/., This article reproduces the contents of the White Paper entitled by the same name submitted to the call issued by the European Space Agency soliciting ideas from the scientific community for the science themes that should be covered during the Voyage 2050 planning cycle. This contribution focus in the investigation of the emergence of life and the role that astronomy has to play in it. Three fundamental areas of activity are identified: [1] measuring the chemical enrichment of the Universe, [2] investigating planet formation and searching for exoplanets with signatures of life and, [3] determining the abundance of amino acids and the chemical routes to amino acid and protein growth in astronomical bodies. This proposal deals with the first two. The building blocks of life in the Universe began as primordial gas processed in stars and mixed at galactic scales. The mechanisms responsible for this development are not well-understood and have changed over the intervening 13 billion years. To follow the evolution of matter over cosmic time, it is necessary to study the strongest (resonance) transitions of the most abundant species in the Universe. Most of them are in the ultraviolet (UV; 950 Å - 3000 Å ) spectral range that is unobservable from the ground; the “missing” metals problem cannot be addressed without this access. Habitable planets grow in protostellar discs under ultraviolet irradiation, a by-product of the accretion process that drives the physical and chemical evolution of discs and young planetary systems. The electronic transitions of the most abundant molecules are pumped by this UV field that is the main oxidizing agent in the disc chemistry and provides unique diagnostics of the planet-forming environment that cannot be accessed from the ground. Knowledge of the variability of the UV radiation field is required for the astrochemical modelling of protoplanetary discs, to understand the formation of planetary atmospheres and the photochemistry of the precursors of life. Earth’s atmosphere is in constant interaction with the interplanetary medium and the solar UV radiation field. The exosphere of the Earth extends up to 35 planetary radii providing an amazing wealth of information on our planet’s winds and the atmospheric compounds. To access to it in other planetary systems, observation of the UV resonance transitions is required. The investigation for the emergence of life calls for the development of large astronomical facilities, including instrumentation in optical and UV wavelengths. In this contribution, the need to develop a large observatory in the optical and in the UV is revealed, in order to complete the scientific goals to investigate the origin of life, inaccessible through other frequencies in the electromagnetic spectrum. © 2022, The Author(s)., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

Published
2022

4. Building galaxies, stars, planets and the ingredients for life between the stars. The science behind the European Ultraviolet-Visible Observatory

Author

Ana I. Gómez de Castro, Thierry Appourchaux, Martin A. Barstow, Mathieu Barthelemy, Frederic Baudin, Stefano Benetti, Pere Blay, Noah Brosch, Emma Bunce, Domitilla de Martino, Jean-Michel Deharveng, Roger Ferlet, Kevin France, Miriam García, Boris Gänsicke, Cecile Gry, Lynne Hillenbrand, Eric Josselin, Carolina Kehrig, Laurent Lamy, Jon Lapington, Alain Lecavelier des Etangs, Frank LePetit, Javier López-Santiago, Bruno Milliard, Richard Monier, Giampiero Naletto, Yael Nazé, Coralie Neiner, Jonathan Nichols, Marina Orio, Isabella Pagano, Céline Peroux, Gregor Rauw, Steven Shore, Marco Spaans, Gagik Tovmassian, Asif ud-Doula, José Vilchez, Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), The Wise Observatory and The Raymond & Beverly Sackler School of Physics and Astronomy, Tel Aviv University [Tel Aviv], Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Center for Astrophysics and Space Astronomy [Boulder] (CASA), University of Colorado [Boulder], Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Groupe de Recherche en Astronomie et Astrophysique du Languedoc (GRAAL), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Centre de Recherche en Économie et Statistique (CREST), Ecole Nationale de la Statistique et de l'Analyse de l'Information [Bruz] (ENSAI)-École polytechnique (X)-École Nationale de la Statistique et de l'Administration Économique (ENSAE Paris)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Pennsylvania State University (Penn State), Penn State System, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Tel Aviv University (TAU), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Padova = University of Padua (Unipd), and Kapteyn Astronomical Institute

Subjects
Solar System, 7. Clean energy, Ultraviolet: solar system, Astrobiology, Instrumentation: telescopes, Observatory, Planet, Astrophysics::Solar and Stellar Astrophysics, Ultraviolet: general, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, Physics, [PHYS]Physics [physics], Ultraviolet: ISM, Planetary habitability, Astronomy and Astrophysics, Planetary system, Exoplanet, Galaxy, Ultraviolet: stars, 13. Climate action, Space and Planetary Science, Ultraviolet: galaxies, Extraterrestrial life, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Instrumentation: miscellaneous
Abstract

This contribution gathers the contents of the white paper submitted by the UV community to the Call issued by the European Space Agency in March 2013, for the definition of the L2 and L3 missions in the ESA science program. We outlined the key science that a large UV facility would make possible and the instrumentation to be implemented. The growth of luminous structures and the building blocks of life in the Universe began as primordial gas was processed in stars and mixed at galactic scales. The mechanisms responsible for this development are not well-understood and have changed over the intervening 13 billion years. To follow the evolution of matter over cosmic time, it is necessary to study the strongest (resonance) transitions of the most abundant species in the Universe. Most of them are in the ultraviolet (UV; 950 Å–3000 Å) spectral range that is unobservable from the ground. A versatile space observatory with UV sensitivity a factor of 50–100 greater than existing facilities will revolutionize our understanding of the Universe. Habitable planets grow in protostellar discs under ultraviolet irradiation, a by-product of the star-disk interaction that drives the physical and chemical evolution of discs and young planetary systems. The electronic transitions of the most abundant molecules are pumped by this UV field, providing unique diagnostics of the planet-forming environment that cannot be accessed from the ground. Earth’s atmosphere is in constant interaction with the interplanetary medium and the solar UV radiation field. A 50–100 times improvement in sensitivity would enable the observation of the key atmospheric ingredients of Earth-like exoplanets (carbon, oxygen, ozone), provide crucial input for models of biologically active worlds outside the solar system, and provide the phenomenological baseline to understand the Earth atmosphere in context.

Published
2014
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5. Worlds Beyond: A Strategy for the Detection and Characterization of Exoplanets Executive Summary of a Report of the ExoPlanet Task Force Astronomy and Astrophysics Advisory Committee Washington, DC June 23, 2008.

Author

Jonathan I. Lunine, Debra Fischer, H.B. Hammel, Thomas Henning, Lynne Hillenbrand, James Kasting, Greg Laughlin, Bruce Macintosh, Mark Marley, Gary Melnick, David Monet, Charley Noecker, Stan Peale, Andreas Quirrenbach, Sara Seager, and Joshua N. Winn

Published
2008
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6. CHARACTERIZATION OF THE COMPANION μ HER.

Author

Lewis C. Roberts Jr., Brian D. Mason, Jonathan Aguilar, Joseph Carson, Justin Crepp, Charles Beichman, Douglas Brenner, Rick Burruss, Eric Cady, Statia Luszcz-Cook, Richard Dekany, Lynne Hillenbrand, Sasha Hinkley, David King, Thomas G. Lockhart, Ricky Nilsson, Rebecca Oppenheimer, Ian R. Parry, Laurent Pueyo, and Emily L. Rice

Published
2016
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7. TESTS OF THE PLANETARY HYPOTHESIS FOR PTFO 8-8695b.

Author

Liang Yu, Joshua N. Winn, Saul Rappaport, Fei Dai, Amaury H. M. J. Triaud, Philip Muirhead, Michaël Gillon, Laetitia Delrez, Emmanuel Jehin, Monika Lendl, Simon Albrecht, Allyson Bieryla, Matthew J. Holman, Benjamin T. Montet, Lynne Hillenbrand, Andrew W. Howard, Chelsea X. Huang, Howard Isaacson, and Roberto Sanchis-Ojeda

Subjects
T Tauri stars, PLANETARY orbits, LIGHT curves, TIME series analysis, OCCULTATIONS (Astronomy)
Abstract

The T Tauri star PTFO 8-8695 exhibits periodic fading events that have been interpreted as the transits of a giant planet on a precessing orbit. Here we present three tests of the planet hypothesis. First, we sought evidence for the secular changes in light-curve morphology that are predicted to be a consequence of orbital precession. We observed 28 fading events spread over several years and did not see the expected changes. Instead, we found that the fading events are not strictly periodic. Second, we attempted to detect the planet's radiation, based on infrared observations spanning the predicted times of occultations. We ruled out a signal of the expected amplitude. Third, we attempted to detect the Rossiter–McLaughlin effect by performing high-resolution spectroscopy throughout a fading event. No effect was seen at the expected level, ruling out most (but not all) possible orientations for the hypothetical planetary orbit. Our spectroscopy also revealed strong, time-variable, high-velocity Hα and Ca H & K emission features. All these observations cast doubt on the planetary hypothesis, and suggest instead that the fading events represent starspots, eclipses by circumstellar dust, or occultations of an accretion hotspot. [ABSTRACT FROM AUTHOR]

Published
2015
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8. KNOW THE STAR, KNOW THE PLANET. V. CHARACTERIZATION OF THE STELLAR COMPANION TO THE EXOPLANET HOST STAR HD 177830.

Author

Lewis C. Roberts Jr., Rebecca Oppenheimer, Justin R. Crepp, Christoph Baranec, Charles Beichman, Douglas Brenner, Rick Burruss, Eric Cady, Statia Luszcz-Cook, Richard Dekany, Lynne Hillenbrand, Sasha Hinkley, David King, Thomas G. Lockhart, Ricky Nilsson, Ian R. Parry, Laurent Pueyo, Anand Sivaramakrishnan, Rémi Soummer, and Emily L. Rice

Published
2015
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