Recurring Planetary Debris Transits and Circumstellar Gas Around White Dwarf ZTF J0328–1219
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Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born. -
Early Observations of the Interstellar Comet 2I/Borisov
geosciences Article Early Observations of the Interstellar Comet 2I/Borisov Chien-Hsiu Lee NSF’s National Optical-Infrared Astronomy Research Laboratory, Tucson, AZ 85719, USA; [email protected]; Tel.: +1-520-318-8368 Received: 26 November 2019; Accepted: 11 December 2019; Published: 17 December 2019 Abstract: 2I/Borisov is the second ever interstellar object (ISO). It is very different from the first ISO ’Oumuamua by showing cometary activities, and hence provides a unique opportunity to study comets that are formed around other stars. Here we present early imaging and spectroscopic follow-ups to study its properties, which reveal an (up to) 5.9 km comet with an extended coma and a short tail. Our spectroscopic data do not reveal any emission lines between 4000–9000 Angstrom; nevertheless, we are able to put an upper limit on the flux of the C2 emission line, suggesting modest cometary activities at early epochs. These properties are similar to comets in the solar system, and suggest that 2I/Borisov—while from another star—is not too different from its solar siblings. Keywords: comets: general; comets: individual (2I/Borisov); solar system: formation 1. Introduction 2I/Borisov was first seen by Gennady Borisov on 30 August 2019. As more observations were conducted in the next few days, there was growing evidence that this might be an interstellar object (ISO), especially its large orbital eccentricity. However, the first astrometric measurements do not have enough timespan and are not of same quality, hence the high eccentricity is yet to be confirmed. This had all changed by 11 September; where more than 100 astrometric measurements over 12 days, Ref [1] pinned down the orbit elements of 2I/Borisov, with an eccentricity of 3.15 ± 0.13, hence confirming the interstellar nature. -
Lifetimes of Interstellar Dust from Cosmic Ray Exposure Ages of Presolar Silicon Carbide
Lifetimes of interstellar dust from cosmic ray exposure ages of presolar silicon carbide Philipp R. Hecka,b,c,1, Jennika Greera,b,c, Levke Kööpa,b,c, Reto Trappitschd, Frank Gyngarde,f, Henner Busemanng, Colin Madeng, Janaína N. Ávilah, Andrew M. Davisa,b,c,i, and Rainer Wielerg aRobert A. Pritzker Center for Meteoritics and Polar Studies, The Field Museum of Natural History, Chicago, IL 60605; bChicago Center for Cosmochemistry, The University of Chicago, Chicago, IL 60637; cDepartment of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637; dNuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550; ePhysics Department, Washington University, St. Louis, MO 63130; fCenter for NanoImaging, Harvard Medical School, Cambridge, MA 02139; gInstitute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland; hResearch School of Earth Sciences, The Australian National University, Canberra, ACT 2601, Australia; and iEnrico Fermi Institute, The University of Chicago, Chicago, IL 60637 Edited by Mark H. Thiemens, University of California San Diego, La Jolla, CA, and approved December 17, 2019 (received for review March 15, 2019) We determined interstellar cosmic ray exposure ages of 40 large ago. These grains are identified as presolar by their large isotopic presolar silicon carbide grains extracted from the Murchison CM2 anomalies that exclude an origin in the Solar System (13, 14). meteorite. Our ages, based on cosmogenic Ne-21, range from 3.9 ± Presolar stardust grains are the oldest known solid samples 1.6 Ma to ∼3 ± 2 Ga before the start of the Solar System ∼4.6 Ga available for study in the laboratory, represent the small fraction ago. -
Make a Comet Materials: Students Should First Line Their Mixing Bowls with Trash Bags
Build Your Own Comet Prep Time: 30 minutes Grades: 6-8 Lesson Time: 55 minutes Essential Questions: • What is a comet composed of? • What gives a comet its tail? • What makes a comet different from other Near-Earth Objects (NEOs)? Objectives: • Create a physical representation of a comet and its properties. • Observe distinguishable factors between comets and other NEOs. Standards: • MS – PS1-4: Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed. • CCSS.ELA-LITERACY.RST.6-8.3 - Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks. Teacher Prep: • Materials per comet: o 5 lbs. dry ice, ice chest, paper cups, towels, small container (for scooping), wooden or plastic mixing spoon, trash bag, mixing bowl, heavy work gloves, 1 tablespoon or less of starch, 1 tablespoon or less of dark corn syrup (or soda), 1 tablespoon or less of vinegar, 1 tablespoon or less of rubbing alcohol, large beaker, water, 1 c dirt/sand, 1 L of water. • Additional materials: o Hammer or mallet, paper cups, towels, flashlight, hair dryer. • Most of the dry ice needs to be in a fine powder before the students arrive, so use the hammer to do this ahead of time. There should be about 50-60% fine powder in order to hold the comet together. It is best to separate the dry ice ahead of time with towels. • This can also be done as a class demonstration. Teacher Notes/Background: • This lesson was adapted from NASA’s Make Your Own Comet activity. -
Comet Section Observing Guide
Comet Section Observing Guide 1 The British Astronomical Association Comet Section www.britastro.org/comet BAA Comet Section Observing Guide Front cover image: C/1995 O1 (Hale-Bopp) by Geoffrey Johnstone on 1997 April 10. Back cover image: C/2011 W3 (Lovejoy) by Lester Barnes on 2011 December 23. © The British Astronomical Association 2018 2018 December (rev 4) 2 CONTENTS 1 Foreword .................................................................................................................................. 6 2 An introduction to comets ......................................................................................................... 7 2.1 Anatomy and origins ............................................................................................................................ 7 2.2 Naming .............................................................................................................................................. 12 2.3 Comet orbits ...................................................................................................................................... 13 2.4 Orbit evolution .................................................................................................................................... 15 2.5 Magnitudes ........................................................................................................................................ 18 3 Basic visual observation ........................................................................................................ -
The Comet's Tale
THE COMET’S TALE Newsletter of the Comet Section of the British Astronomical Association Volume 5, No 1 (Issue 9), 1998 May A May Day in February! Comet Section Meeting, Institute of Astronomy, Cambridge, 1998 February 14 The day started early for me, or attention and there were displays to correct Guide Star magnitudes perhaps I should say the previous of the latest comet light curves in the same field. If you haven’t day finished late as I was up till and photographs of comet Hale- got access to this catalogue then nearly 3am. This wasn’t because Bopp taken by Michael Hendrie you can always give a field sketch the sky was clear or a Valentine’s and Glynn Marsh. showing the stars you have used Ball, but because I’d been reffing in the magnitude estimate and I an ice hockey match at The formal session started after will make the reduction. From Peterborough! Despite this I was lunch, and I opened the talks with these magnitude estimates I can at the IOA to welcome the first some comments on visual build up a light curve which arrivals and to get things set up observation. Detailed instructions shows the variation in activity for the day, which was more are given in the Section guide, so between different comets. Hale- reminiscent of May than here I concentrated on what is Bopp has demonstrated that February. The University now done with the observations and comets can stray up to a offers an undergraduate why it is important to be accurate magnitude from the mean curve, astronomy course and lectures are and objective when making them. -
Initial Characterization of Interstellar Comet 2I/Borisov
Initial characterization of interstellar comet 2I/Borisov Piotr Guzik1*, Michał Drahus1*, Krzysztof Rusek2, Wacław Waniak1, Giacomo Cannizzaro3,4, Inés Pastor-Marazuela5,6 1 Astronomical Observatory, Jagiellonian University, Kraków, Poland 2 AGH University of Science and Technology, Kraków, Poland 3 SRON, Netherlands Institute for Space Research, Utrecht, the Netherlands 4 Department of Astrophysics/IMAPP, Radboud University, Nijmegen, the Netherlands 5 Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, the Netherlands 6 ASTRON, Netherlands Institute for Radio Astronomy, Dwingeloo, the Netherlands * These authors contributed equally to this work; email: [email protected], [email protected] Interstellar comets penetrating through the Solar System had been anticipated for decades1,2. The discovery of asteroidal-looking ‘Oumuamua3,4 was thus a huge surprise and a puzzle. Furthermore, the physical properties of the ‘first scout’ turned out to be impossible to reconcile with Solar System objects4–6, challenging our view of interstellar minor bodies7,8. Here, we report the identification and early characterization of a new interstellar object, which has an evidently cometary appearance. The body was discovered by Gennady Borisov on 30 August 2019 UT and subsequently identified as hyperbolic by our data mining code in publicly available astrometric data. The initial orbital solution implies a very high hyperbolic excess speed of ~32 km s−1, consistent with ‘Oumuamua9 and theoretical predictions2,7. Images taken on 10 and 13 September 2019 UT with the William Herschel Telescope and Gemini North Telescope show an extended coma and a faint, broad tail. We measure a slightly reddish colour with a g′–r′ colour index of 0.66 ± 0.01 mag, compatible with Solar System comets. -
Academic Zodiac & RTRRT Publications
Oh, look: it's full of stars! http://lulu.com/astrology The Happiness Formula is 22:16. First published by Klaudio Zic Publications, 2011 http://stores.lulu.com/astrology Copyright © 2011 By Klaudio Zic. All Rights Reserved. No part of this material may be reproduced or transmitted in any form or by any means, electronic or otherwise, for commercial purposes or otherwise, without the written permission of the Author. The names of dedicated publications are normally given in italics. Academic Zodiac & RTRRT Publications Copyright © 2011 by Klaudio Zic, all rights reserved. http://www.lulu.com/astrology Is there a happiness formula? If there is one, we believe we have found it. From time immemorial, we have been told to tell the truth in order to be happy forever after; well, here it is: your own true horoscope according to the original zodiac. If you were looking for truth, the search ends here: you have found the Academic Zodiac. Your true stars will help your original mind out of its frozen niche. A bit dusty after years of hibernation, your original self bursts open within a world of infinite possibilities. You can create and recreate events much as you can discreate the unwanted ones forever. Buss the slumbering princess, kiss the frog & prince charming and welcome to your enchanted kingdom full of goodies and birthright charms. Academic Zodiac & RTRRT Publications How does one find an appropriate publication? The publication of your own choice is found by searching the lulu.com site for relevant results. The helpful site inkmesh.com is particularly useful in determining price range, e.g. -
Astronomy Astrophysics
A&A 432, 515–529 (2005) Astronomy DOI: 10.1051/0004-6361:20040331 & c ESO 2005 Astrophysics PAH charge state distribution and DIB carriers: Implications from the line of sight toward HD 147889, R. Ruiterkamp1,N.L.J.Cox2,M.Spaans3, L. Kaper2,B.H.Foing4,F.Salama5, and P. Ehrenfreund2 1 Leiden Observatory, PO Box 9513, 2300 RA Leiden, The Netherlands e-mail: [email protected] 2 Institute Anton Pannekoek, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands 3 Kapteyn Astronomical Institute, PO Box 800, 9700 AV Groningen, The Netherlands 4 ESA Research and Scientific Support Department, PO Box 299, 2200 AG Noordwijk, The Netherlands 5 Space Science Division, NASA Ames Research Center, Mail Stop 245-6, Moffett Field, California 94035, USA Received 25 February 2004 / Accepted 29 September 2004 Abstract. We have computed physical parameters such as density, degree of ionization and temperature, constrained by a large observational data set on atomic and molecular species, for the line of sight toward the single cloud HD 147889. Diffuse interstellar bands (DIBs) produced along this line of sight are well documented and can be used to test the PAH hypothesis. To this effect, the charge state fractions of different polycyclic aromatic hydrocarbons (PAHs) are calculated in HD 147889 as a function of depth for the derived density, electron abundance and temperature profile. As input for the construction of these charge state distributions, the microscopic properties of the PAHs, e.g., ionization potential and electron affinity, are determined for a series of symmetry groups. The combination of a physical model for the chemical and thermal balance of the gas toward HD 147889 with a detailed treatment of the PAH charge state distribution, and laboratory and theoretical data on specific PAHs, allow us to compute electronic spectra of gas phase PAH molecules and to draw conclusions about the required properties of PAHs as DIB carriers. -
Physical Processes in the Interstellar Medium
Physical Processes in the Interstellar Medium Ralf S. Klessen and Simon C. O. Glover Abstract Interstellar space is filled with a dilute mixture of charged particles, atoms, molecules and dust grains, called the interstellar medium (ISM). Understand- ing its physical properties and dynamical behavior is of pivotal importance to many areas of astronomy and astrophysics. Galaxy formation and evolu- tion, the formation of stars, cosmic nucleosynthesis, the origin of large com- plex, prebiotic molecules and the abundance, structure and growth of dust grains which constitute the fundamental building blocks of planets, all these processes are intimately coupled to the physics of the interstellar medium. However, despite its importance, its structure and evolution is still not fully understood. Observations reveal that the interstellar medium is highly tur- bulent, consists of different chemical phases, and is characterized by complex structure on all resolvable spatial and temporal scales. Our current numerical and theoretical models describe it as a strongly coupled system that is far from equilibrium and where the different components are intricately linked to- gether by complex feedback loops. Describing the interstellar medium is truly a multi-scale and multi-physics problem. In these lecture notes we introduce the microphysics necessary to better understand the interstellar medium. We review the relations between large-scale and small-scale dynamics, we con- sider turbulence as one of the key drivers of galactic evolution, and we review the physical processes that lead to the formation of dense molecular clouds and that govern stellar birth in their interior. Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Straße 2, 69120 Heidelberg, Germany e-mail: [email protected], [email protected] 1 Contents Physical Processes in the Interstellar Medium ............... -
Laboratory Astrophysics: from Observations to Interpretation
April 14th – 19th 2019 Jesus College Cambridge UK IAU Symposium 350 Laboratory Astrophysics: From Observations to Interpretation Poster design by: D. Benoit, A. Dawes, E. Sciamma-O’Brien & H. Fraser Scientific Organizing Committee: Local Organizing Committee: Farid Salama (Chair) ★ P. Barklem ★ H. Fraser ★ T. Henning H. Fraser (Chair) ★ D. Benoit ★ R Coster ★ A. Dawes ★ S. Gärtner ★ C. Joblin ★ S. Kwok ★ H. Linnartz ★ L. Mashonkina ★ T. Millar ★ D. Heard ★ S. Ioppolo ★ N. Mason ★ A. Meijer★ P. Rimmer ★ ★ O. Shalabiea★ G. Vidali ★ F. Wa n g ★ G. Del-Zanna E. Sciamma-O’Brien ★ F. Salama ★ C. Wa lsh ★ G. Del-Zanna For more information and to contact us: www.astrochemistry.org.uk/IAU_S350 [email protected] @iaus350labastro 2 Abstract Book Scheduley Sunday 14th April . Pg. 2 Monday 15th April . Pg. 3 Tuesday 16th April . Pg. 4 Wednesday 17th April . Pg. 5 Thursday 18th April . Pg. 6 Friday 19th April . Pg. 7 List of Posters . .Pg. 8 Abstracts of Talks . .Pg. 12 Abstracts of Posters . Pg. 83 yPlenary talks (40') are indicated with `P', review talks (30') with `R', and invited talks (15') with `I'. Schedule Sunday 14th April 14:00 - 17:00 REGISTRATION 18:00 - 19:00 WELCOME RECEPTION 19:30 DINNER BAR OPEN UNTIL 23:00 Back to Table of Contents 2 Monday 15th April 09:00 { 10:00 REGISTRATION 09:00 WELCOME by F. Salama (Chair of SOC) SESSION 1 CHAIR: F. Salama 09:15 E. van Dishoeck (P) Laboratory astrophysics: key to understanding the Universe From Diffuse Clouds to Protostars: Outstanding Questions about the Evolution of 10:00 A. -
Detection of Exocometary CO Within the 440 Myr Old Fomalhaut Belt: a Similar CO+CO2 Ice Abundance in Exocomets and Solar System Comets
UCLA UCLA Previously Published Works Title Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO2 Ice Abundance in Exocomets and Solar System Comets Permalink https://escholarship.org/uc/item/1zf7t4qn Journal Astrophysical Journal, 842(1) ISSN 0004-637X Authors Matra, L MacGregor, MA Kalas, P et al. Publication Date 2017-06-10 DOI 10.3847/1538-4357/aa71b4 Peer reviewed eScholarship.org Powered by the California Digital Library University of California The Astrophysical Journal, 842:9 (15pp), 2017 June 10 https://doi.org/10.3847/1538-4357/aa71b4 © 2017. The American Astronomical Society. All rights reserved. Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO2 Ice Abundance in Exocomets and Solar System Comets L. Matrà1, M. A. MacGregor2, P. Kalas3,4, M. C. Wyatt1, G. M. Kennedy1, D. J. Wilner2, G. Duchene3,5, A. M. Hughes6, M. Pan7, A. Shannon1,8,9, M. Clampin10, M. P. Fitzgerald11, J. R. Graham3, W. S. Holland12, O. Panić13, and K. Y. L. Su14 1 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK; [email protected] 2 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 3 Astronomy Department, University of California, Berkeley CA 94720-3411, USA 4 SETI Institute, Mountain View, CA 94043, USA 5 Univ. Grenoble Alpes/CNRS, IPAG, F-38000 Grenoble, France 6 Department of Astronomy, Van Vleck Observatory, Wesleyan University, 96 Foss Hill Dr., Middletown, CT 06459, USA 7 MIT Department of Earth, Atmospheric, and