Surface Layer Independent Model Fitting by Phase Matching
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Hydrodynamical Simulations of Convection-Related Stellar Micro-Variability II
A&A 506, 167–173 (2009) Astronomy DOI: 10.1051/0004-6361/200911930 & c ESO 2009 Astrophysics The CoRoT space mission: early results Special feature Hydrodynamical simulations of convection-related stellar micro-variability II. The enigmatic granulation background of the CoRoT target HD 49933 H.-G. Ludwig1,, R. Samadi2,M.Steffen3, T. Appourchaux4 ,F.Baudin4, K. Belkacem5, P. Boumier2, M.-J. Goupil2, and E. Michel2 1 GEPI, Observatoire de Paris, CNRS, Univ. Paris 7, 92195 Meudon Cedex, France e-mail: [email protected] 2 LESIA, Observatoire de Paris, CNRS (UMR 8109), Univ. Paris 6, Univ. Paris 7, 92195 Meudon Cedex, France 3 Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany 4 Institut d’Astrophysique Spatiale, Univ. Paris 11, CNRS (UMR 8617), 91405 Orsay, France 5 Institut d’Astrophysique et de Géophysique de l’Université de Liège, Allée du 6 Août 17, 4000 Liège, Belgium Received 23 February 2009 / Accepted 17 April 2009 ABSTRACT Context. Local-box hydrodynamical model atmospheres provide statistical information about a star’s emergent radiation field which allows one to predict the level of its granulation-related micro-variability. Space-based photometry is now sufficiently accurate to test model predictions. Aims. We aim to model the photometric granulation background of HD 49933 as well as the Sun, and compare the predictions to the measurements obtained by the CoRoT and SOHO satellite missions. Methods. We construct hydrodynamical model atmospheres representing HD 49933 and the Sun, and use a previously developed scaling technique to obtain the observable disk-integrated brightness fluctuations. We further performed exploratory magneto- hydrodynamical simulations to gauge the impact of small scale magnetic fields on the synthetic light-curves. -
Communications in Asteroseismology
Communications in Asteroseismology Volume 156 November/December, 2008 Communications in Asteroseismology Editor-in-Chief: Michel Breger, [email protected] Editorial Assistant: Daniela Klotz, [email protected] Layout & Production Manager: Paul Beck, [email protected] Language Editor: Natalie Sas, [email protected] Institut f¨ur Astronomie der Universit¨at Wien T¨urkenschanzstraße 17, A - 1180 Wien, Austria http://www.univie.ac.at/tops/CoAst/ [email protected] Editorial Board: Conny Aerts, Gerald Handler, Don Kurtz, Jaymie Matthews, Ennio Poretti Cover Illustration The Milky Way behind the dome of the 40-inch telescope at the Siding Spring Observatory, Australia. Data from this telescope is used in a paper by Handler & Shobbrook in this issue (see page 18). (Photo kindly provided by R. R. Shobbrook) British Library Cataloguing in Publication data. A Catalogue record for this book is available from the British Library. All rights reserved ISBN 978-3-7001-6539-2 ISSN 1021-2043 Copyright c 2008 by Austrian Academy of Sciences Vienna Austrian Academy of Sciences Press A-1011 Wien, Postfach 471, Postgasse 7/4 Tel. +43-1-515 81/DW 3402-3406, +43-1-512 9050 Fax +43-1-515 81/DW 3400 http://verlag.oeaw.ac.at, e-mail: [email protected] Comm. in Asteroseismology Vol. 156, 2008 Introductory Remarks The summer of 2008 was a densely packed season with a number of excellent astero- seismological conferences. CoAst will publish the proceedings of the Wroclaw, Liege and Vienna (JENAM) meetings. In fact, the proceedings of the HELAS Wroclaw conference is mailed to you together with this regular issue. -
Arxiv:1202.1422V2 [Astro-Ph.SR] 17 Feb 2012 Dtdb .Bgi,M Eei,E Ihl&C Moutou C
Transiting planets, vibrating stars & their connection nd Proceedings of the 2 CoRoT symposium (14 - 17 June 2011, Marseille) Edited by A. Baglin, M. Deleuil, E. Michel & C. Moutou Some CoRoT highlights - A grip on stellar physics and beyond E. Michel1, A. Baglin1 and the CoRoT Team 1 LESIA, Observatoire de Paris, CNRS UMR 8109, Univ. Pierre et Marie Curie, Univ. Paris Diderot, pl. J. Janssen, 92195 Meudon, France [[email protected]] Abstract. About 2 years ago, back in 2009, the first CoRoT Symposium was the occasion to present and discuss unprecedented data revealing the behaviour of stars at the micro- magnitude level. Since then, the observations have been going on, the target sample has enriched and the work of analysis of these data keeps producing first rank results. These analyses are providing the material to address open questions of stellar structure and evolution and to test the so many physical processes at work in stars. Based on this material, an increasing number of interpretation studies is being published, addressing various key aspects: the extension of mixed cores, the structure of near surface convective zones, magnetic activity, mass loss, ... Definitive conclusions will require cross-comparison of results on a larger ground (still being built), but it is already possible at the time of this Second CoRoT Symposium, to show how the various existing results take place in a general framework and contribute to complete our initial scientific objectives. A few results already reveal the potential interest in considering stars and planets globally, as it is stressed in several talks at this symposium. -
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Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 2052 Statistical Methods in Quantitative Spectroscopy of Solar-Type Stars ALVIN GAVEL ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-513-1237-8 UPPSALA URN urn:nbn:se:uu:diva-446479 2021 Dissertation presented at Uppsala University to be publicly examined on Zoom, Friday, 10 September 2021 at 13:00 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Dr. Coryn Bailer-Jones (Max Planck Institute for Astronomy). Online defence: https://uu-se.zoom.us/my/alvinzoomroom Abstract Gavel, A. 2021. Statistical Methods in Quantitative Spectroscopy of Solar-Type Stars. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 2052. 115 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-1237-8. Galactic archaeology is the research field that attempts to reconstruct the history of the Milky Way, using primarily the tools of astrometric studies and chemical studies. The latter in turn uses stellar spectroscopy. Thanks to technological advances, the field of stellar spectroscopy now has access to much larger amounts of observational data than it used to. At the same time, also thanks to technological advances, the field able to use increasingly more sophisticated modelling. This opens up for the possibility of attacking research problems in Galactic archaeology that were previously intractable. However, it also creates a problem: Access to greater amounts of data means that the random errors in studies will tend to shrink, while the systematic errors tend to stay of the same size. -
HD 203608, a Quiet Asteroseismic Target in the Old Galactic Disk B
HD 203608, a quiet asteroseismic target in the old galactic disk B. Mosser, S. Deheuvels, E. Michel, F. Thévenin, M.A. Dupret, R. Samadi, C. Barban, M.J. Goupil To cite this version: B. Mosser, S. Deheuvels, E. Michel, F. Thévenin, M.A. Dupret, et al.. HD 203608, a quiet asteroseismic target in the old galactic disk. Astronomy and Astrophysics - A&A, EDP Sciences, 2008, 488, pp.635- 642. 10.1051/0004-6361:200810011. hal-00382990 HAL Id: hal-00382990 https://hal.archives-ouvertes.fr/hal-00382990 Submitted on 28 Apr 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A&A 488, 635–642 (2008) Astronomy DOI: 10.1051/0004-6361:200810011 & c ESO 2008 Astrophysics HD 203608, a quiet asteroseismic target in the old galactic disk, B. Mosser1, S. Deheuvels1,E.Michel1,F.Thévenin2,M.A.Dupret1,R.Samadi1,C.Barban1, and M. J. Goupil1 1 LESIA, CNRS, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, 92195 Meudon Cedex, France e-mail: [email protected] 2 Laboratoire Cassiopée, Université de Nice Sophia Antipolis, Observatoire de la Côte d’Azur, CNRS, BP 4229, 06304 Nice Cedex 4, France Received 19 April 2008 / Accepted 10 June 2008 ABSTRACT Context. -
The Corot Observations A
The CoRoT Legacy Book c The authors, 2016 DOI: 10.1051/978-2-7598-1876-1.c021 II.1 The CoRoT observations A. Baglin1, S. Chaintreuil1, and O. Vandermarcq2 1 LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universites,´ UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cite,´ 5 place Jules Janssen, 92195 Meudon, France 2 CNES, Centre spatial de Toulouse, 18 avenue Edouard Belin, 31 401 Toulouse Cedex 9, France This chapter explains how it has been possible to propose Calls for AP proposals are sent as soon as the field of a reasonable mission, taking into account the scientific ob- a run is approximately chosen. They contain either general jectives and the mission constraints. scientific studies or specific targets. It shows how the scientific specifications have been The necessity to observe at the same time, for long dura- translated in the observation programme and its successive tions, bright targets devoted to the seismology programme, runs. and faint ones for the exoplanet finding objective have lead It describes the observations from all aspects: selection to difficult compromises on the instrument, the satellite and criteria (scientific and operational), tools, implementation, the mission profile. global results and specific results. A preliminary proposal for a nominal mission of 2.5 yr A particular focus is made on evolution, showing how was built before the mission, but has been adjusted during scientists and engineers in charge of the operations at CNES the flight before each observing period, taking into account and in the laboratories have adapted the major principles the previous results. -
Convective Boundary Mixing in Low-And Intermediate-Mass Stars I. Core Properties from Pressure-Mode Asteroseismology
MNRAS 000,1{20 (2019) Preprint 18 February 2020 Compiled using MNRAS LATEX style file v3.0 Convective boundary mixing in low- and intermediate-mass stars I. Core properties from pressure-mode asteroseismology George C. Angelou,1;3? Earl P. Bellinger2, Saskia Hekker3;2, Alexey Mints3;4, Yvonne Elsworth5;2, Sarbani Basu6 and Achim Weiss1 1Max-Planck Institut fur¨ Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany 2Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark 3Max-Planck-Institut fur¨ Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 G¨ottingen, Germany 4Leibniz Institute for Astrophyics Potsdam (AIP), Ander Sternwarte 16, D-14482 Potsdam, Germany 5School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK 6Department of Astronomy, Yale University, New Haven, Connecticut, USA Accepted XXX. Received YYY; in original form ZZZ ABSTRACT Convective boundary mixing (CBM) is ubiquitous in stellar evolution. It is a necessary ingredient in the models in order to match observational constraints from clusters, binaries and single stars alike. We compute `effective overshoot' measures that reflect the extent of mixing and which can differ significantly from the input overshoot values set in the stellar evolution codes. We use constraints from pressure modes to infer the CBM properties of Kepler and CoRoT main-sequence and subgiant oscillators, as well as in two radial velocity targets (Procyon A and α Cen A). Collectively these targets allow us to identify how measurement precision, stellar spectral type, and overshoot implementation impact the asteroseismic solution. With these new measures we find that the `effective overshoot' for most stars is in line with physical expectations and calibrations from binaries and clusters. -
One Million Dollars
New In The Mountain Views: Sports are back! Page 14 Plus......On The Course with Bobby Eldridge SATURDAY SEPTEMBER 4, 2010 VOLUME 4 NO. 35 One Million Dollars A Taste of Sierra Madre The first festival showcasing the ‘flavor’ of this treasured foothill Village. A day of fine arts, great food, live music, and unique design on Sept 11, 2010 Schedule of Events 9:00 AM to Coolest Kitchen 1:00 PM Tours 10:00 AM Kersting Court Opening Ceremonies Gooden School Ensemble Student Fine Arts Awards Drama performance from St. Rita School Bethany Christian School Student musical performances 11:30 AM FOOD COURT in Kersting Court until 2 p.m. Noon Presentation of Grand Prizes for Student Art and Essay Contest Police & Fire Department Chili Cook off For the second time in less than a year, Happy’s Liquors in Sierra Madre Jandal Singh holds the kind of scratcher that held the winning numbers. Eric Byak Project Live Music has sold a winning lottery ticket. A lucky Sierra Madre resident, who According to Singh, Happy’s Liquors will recieve $10,000 from the shall remain nameless, won a million dollars by purchasing the lucky California Lottery for selling the winning ticket. 12:30 PM Chef Chris Allen ‘Scratcher’ at Happy’s. Happy’s Liquors is located on the corner of Sierra Madre Blvd. and Chocolate Truffle Demonstration In November, the store sold a winning Super Lotto ticket worth more Baldwin Avenue in Sierra Madre. Photo by S. Henderson than $191,000. 12:45 PM Cheryl Barnes & Dr. Phil Cabasso vocals and jazz City To Celebrate New Radio Station HEADLINERS CONCERT: The City of Sierra Madre will hold a ribbon cutting The Sierra Madre City ceremony to celebrate its new emergency radio station Council appropriated SME Auditorium at 141 W. -
Annual Report 2009 ESO
ESO European Organisation for Astronomical Research in the Southern Hemisphere Annual Report 2009 ESO European Organisation for Astronomical Research in the Southern Hemisphere Annual Report 2009 presented to the Council by the Director General Prof. Tim de Zeeuw The European Southern Observatory ESO, the European Southern Observa tory, is the foremost intergovernmental astronomy organisation in Europe. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Several other countries have expressed an interest in membership. Created in 1962, ESO carries out an am bitious programme focused on the de sign, construction and operation of power ful groundbased observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world View of the La Silla Observatory from the site of the One of the most exciting features of the class observing sites in the Atacama 3.6 metre telescope, which ESO operates together VLT is the option to use it as a giant opti with the New Technology Telescope, and the MPG/ Desert region of Chile: La Silla, Paranal ESO 2.2metre Telescope. La Silla also hosts national cal interferometer (VLT Interferometer or and Chajnantor. ESO’s first site is at telescopes, such as the Swiss 1.2metre Leonhard VLTI). This is done by combining the light La Silla, a 2400 m high mountain 600 km Euler Telescope and the Danish 1.54metre Teles cope. -
II.1 the Corot Observations A
The CoRoT Legacy Book c The authors, 2016 DOI: 10.1051/978-2-7598-1876-1.c021 II.1 The CoRoT observations A. Baglin1, S. Chaintreuil1, and O. Vandermarcq2 1 LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universites,´ UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cite,´ 5 place Jules Janssen, 92195 Meudon, France 2 CNES, Centre spatial de Toulouse, 18 avenue Edouard Belin, 31 401 Toulouse Cedex 9, France This chapter explains how it has been possible to propose Calls for AP proposals are sent as soon as the field of a reasonable mission, taking into account the scientific ob- a run is approximately chosen. They contain either general jectives and the mission constraints. scientific studies or specific targets. It shows how the scientific specifications have been The necessity to observe at the same time, for long dura- translated in the observation programme and its successive tions, bright targets devoted to the seismology programme, runs. and faint ones for the exoplanet finding objective have lead It describes the observations from all aspects: selection to difficult compromises on the instrument, the satellite and criteria (scientific and operational), tools, implementation, the mission profile. global results and specific results. A preliminary proposal for a nominal mission of 2.5 yr A particular focus is made on evolution, showing how was built before the mission, but has been adjusted during scientists and engineers in charge of the operations at CNES the flight before each observing period, taking into account and in the laboratories have adapted the major principles the previous results. -
HAROLD ALISTER Mcalister
H.A. McAlister, Curriculum Vitae, Version July 2013 HAROLD ALISTER McALISTER PRESENT ADDRESS: Department of Physics and Astronomy 2453 Vivian Circle Georgia State University or Decatur, GA Atlanta, GA 30303 (404) 377-0327 V: (404) 413-5480 F: (404) 413-5481 [email protected] PERSONAL: Born 1 July 1949 at Chattanooga, TN; husband of Susan J. McAlister; father of Merritt Ellen McAlister PROFESSIONAL: EDUCATION: B.A. - Physics - Magna cum Laude - University of Tennessee at Chattanooga - 1971 M.A. - Astronomy - University of Virginia - 1974 Ph.D. - Astronomy - University of Virginia - 1975 POSITIONS HELD: The Girls Preparatory School Instructor of Physics 1970-71 Chattanooga, Tennessee University of Virginia Research Assistant 1971-75 Charlottesville, Virginia Kitt Peak National Observatory Research Associate 1975-77 Tucson, Arizona Georgia State University Assistant Professor 1977-82 Atlanta, Georgia Associate Professor 1982-87 Professor 1987-1998 Regents’ Professor 1998-2011 Regents’ Professor Emeritus 2011-present Director (and founder) of the Center for High Angular Resolution Astronomy 1985-present Mount Wilson Institute Director, Mount Wilson Observatory and Pasadena, California Chief Executive Officer, MWI 2003-present PROFESSIONAL SOCIETIES: American Astronomical Society, International Astronomical Union, Astronomical Society of the Pacific MISCELLANEOUS PROFESSIONAL SERVICE ACTIVITIES: Elected Vice-President of Commission 26 of the International Astronomical Union (IAU), November 1985. Elected President of IAU Commission 26 September 1987. Member of the NSF Astronomy Advisory Committee 1983-86. Member of the NSF Astronomy Oversight Committee 1984. Member of the NSF Presidential Young Investigators Awards Panel for Astronomical, Atmospheric, Earth and Ocean Sciences 1984-85. Member of the NSF panel charged with the distribution of excess Space Telescope charge coupled devices 1985. -
A Summary of the Different Classes of Stellar Pulsators
A Summary of the Different Classes of Stellar Pulsators A summary of all the classes of pulsating stars and their main properties as described in Chapter 2 is given in the tables below. This list originated from a combination of observational discoveries, measured stellar properties, and theoretical developments. Observers who found a new type of pulsator either named it after the prototype or gave the class a name according to the ob- served characteristics of the oscillations. Several pulsators, or even groups of pulsators, were afterwards found to originate from the same physical mech- anism and were thus merged into one and the same class. We sort this out here in Tables A.1 and A.2 in order to avoid further confusion on pulsating star nomenclature. The effective temperature and luminosity indicated in Tables A.1 and A.2 should be taken as rough indications only of the borders of instability strips. Often the theory is not sufficiently refined to consider these boundaries as final. Moreover, there is overlap between various classes where so-called hy- brid pulsators, whose oscillations are excited in two different layers and/or by two different mechanisms, occur. Finally, new discoveries are being made frequently, which then drive new theoretical developments possibly leading to new instability regions. The results from the future observing facilities as described in Chapter 8 will surely lead to new classes and/or subclasses with lower amplitudes compared to what is presently achievable. In the tables below, F stands for fundamental radial mode, FO for first radial overtone and S for strange mode oscillations.