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JOHN R. THORSTENSEN Address
CURRICULUM VITAE: JOHN R. THORSTENSEN Address: Department of Physics and Astronomy Dartmouth College 6127 Wilder Laboratory Hanover, NH 03755-3528; (603)-646-2869 [email protected] Undergraduate Studies: Haverford College, B. A. 1974 Astronomy and Physics double major, High Honors in both. Graduate Studies: Ph. D., 1980, University of California, Berkeley Astronomy Department Dissertation : \Optical Studies of Faint Blue X-ray Stars" Graduate Advisor: Professor C. Stuart Bowyer Employment History: Department of Physics and Astronomy, Dartmouth College: { Professor, July 1991 { present { Associate Professor, July 1986 { July 1991 { Assistant Professor, September 1980 { June 1986 Research Assistant, Space Sciences Lab., U.C. Berkeley, 1975 { 1980. Summer Student, National Radio Astronomy Observatory, 1974. Summer Student, Bartol Research Foundation, 1973. Consultant, IBM Corporation, 1973. (STARMAP program). Honors and Awards: Phi Beta Kappa, 1974. National Science Foundation Graduate Fellow, 1974 { 1977. Dorothea Klumpke Roberts Award of the Berkeley Astronomy Dept., 1978. Professional Societies: American Astronomical Society Astronomical Society of the Pacific International Astronomical Union Lifetime Publication List * \Can Collapsed Stars Close the Universe?" Thorstensen, J. R., and Partridge, R. B. 1975, Ap. J., 200, 527. \Optical Identification of Nova Scuti 1975." Raff, M. I., and Thorstensen, J. 1975, P. A. S. P., 87, 593. \Photometry of Slow X-ray Pulsars II: The 13.9 Minute Period of X Persei." Margon, B., Thorstensen, J., Bowyer, S., Mason, K. O., White, N. E., Sanford, P. W., Parkes, G., Stone, R. P. S., and Bailey, J. 1977, Ap. J., 218, 504. \A Spectrophotometric Survey of the A 0535+26 Field." Margon, B., Thorstensen, J., Nelson, J., Chanan, G., and Bowyer, S. -
Stellar Tidal Streams As Cosmological Diagnostics: Comparing Data and Simulations at Low Galactic Scales
RUPRECHT-KARLS-UNIVERSITÄT HEIDELBERG DOCTORAL THESIS Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Author: Referees: Gustavo MORALES Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL Astronomisches Rechen-Institut Heidelberg Graduate School of Fundamental Physics Department of Physics and Astronomy 14th May, 2018 ii DISSERTATION submitted to the Combined Faculties of the Natural Sciences and Mathematics of the Ruperto-Carola-University of Heidelberg, Germany for the degree of DOCTOR OF NATURAL SCIENCES Put forward by GUSTAVO MORALES born in Copiapo ORAL EXAMINATION ON JULY 26, 2018 iii Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Referees: Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL iv NOTE: Some parts of the written contents of this thesis have been adapted from a paper submitted as a co-authored scientific publication to the Astronomy & Astrophysics Journal: Morales et al. (2018). v NOTE: Some parts of this thesis have been adapted from a paper accepted for publi- cation in the Astronomy & Astrophysics Journal: Morales, G. et al. (2018). “Systematic search for tidal features around nearby galaxies: I. Enhanced SDSS imaging of the Local Volume". arXiv:1804.03330. DOI: 10.1051/0004-6361/201732271 vii Abstract In hierarchical models of galaxy formation, stellar tidal streams are expected around most galaxies. Although these features may provide useful diagnostics of the LCDM model, their observational properties remain poorly constrained. Statistical analysis of the counts and properties of such features is of interest for a direct comparison against results from numeri- cal simulations. In this work, we aim to study systematically the frequency of occurrence and other observational properties of tidal features around nearby galaxies. -
Dark Matter: the Evidence from Astronomy, Astrophysics and Cosmology Matts Roos University of Helsinki [email protected]
Dark Matter: The evidence from astronomy, astrophysics and cosmology Matts Roos University of Helsinki [email protected] Dark matter has been introduced to explain many independent gravitational effects at different astronomical scales, even at cosmological scales. This review describes more than ten such effects. It is intended for an audience with little or no knowledge of astrophysics or cosmology. ContentsContents I. Stars near the Galactic disk II. Virially bound systems III. Rotation curves of spiral galaxies IV. Small galaxy groups emitting X-rays V. Mass to luminosity ratios VI. Mass autocorrelation functions VII. Strong and weak lensing VIII. Cosmic Microwave Background IX. Baryonic acoustic oscillations X. Galaxy formation in purely baryonic matter XI. Large Scale Structures simulated XII. Dark matter from overall fits XIII. Merging galaxy clusters XIV. Conclusions II StarsStars nearnear thethe GalacticGalactic diskdisk ? J. H. Oort in 1932 analyzed vertical motions of stars near the Galactic disk and calculated the vertical acceleration of matter. ? Their density and velocity dispersion define the temperature of a ”star atmosphere” bound by a gravitational potential. ? This contradicted grossly the expectations: the density due to known stars was not sufficient: the Galaxy should rapidly be losing stars. ? This was the first indication for the possible existence of dark matter in the Galaxy. ? He determined the mass of the Milky Way: 1011 solar masses, today understood to be mainly in the halo, not in the disk. ? But dark -
Abstracts Book
CONFERENCE BOOK TASC2 & SEISMOLOGY OF KASC9 THE SUN AND THE / Workshop SPACEINN & DISTANT STARS HELAS8 2016 /USING TODAY’S / Conference SUCCE SSES TO 11–15 July PREPARE THE Angra do Heroísmo Terceira, Açores FUTURE Portugal ORGANIZERS SPONSORS SEISMOLOGY OF THE SUN AND THE DISTANT STARS 2016 USING TODAY’S SUCCESSES TO PREPARE THE FUTURE Scientific Rationale For the last 30 years, since the meeting on Seismology of the Sun and the Distant Stars held in Cambridge, in 1985, the range of seismic data and associated science results obtained has far exceeded the expectations of the community. The continuous observation of the Sun has secured major advances in the understanding of the physics of the stellar interiors and has allowed us to build and prepare the tools to look at other stars. Several ground facilities and space missions have completed the picture by adding the necessary data to study stars across the HR diagram with a level of detail that was in no way foreseen in 1985. In spite of the great science successes, astero- and helioseismic data still contain many secrets waiting to be uncovered. The opportunity to use the existing data and tools to clarify major questions of stellar physics (mixing, rotation, convection, and magnetic activity are just a few examples) still needs to be further explored. The combination of data from different instruments and for different targets also holds the promise that further advances are indeed imminent. At the same time we also need to prepare the future, as major space missions and ground facilities are being built in order to collect more and better data to expand and consolidate the detailed seismic view of the stellar population in our galaxy. -
Naming the Extrasolar Planets
Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named. -
August 13 2016 7:00Pm at the Herrett Center for Arts & Science College of Southern Idaho
Snake River Skies The Newsletter of the Magic Valley Astronomical Society www.mvastro.org Membership Meeting President’s Message Saturday, August 13th 2016 7:00pm at the Herrett Center for Arts & Science College of Southern Idaho. Public Star Party Follows at the Colleagues, Centennial Observatory Club Officers It's that time of year: The City of Rocks Star Party. Set for Friday, Aug. 5th, and Saturday, Aug. 6th, the event is the gem of the MVAS year. As we've done every Robert Mayer, President year, we will hold solar viewing at the Smoky Mountain Campground, followed by a [email protected] potluck there at the campground. Again, MVAS will provide the main course and 208-312-1203 beverages. Paul McClain, Vice President After the potluck, the party moves over to the corral by the bunkhouse over at [email protected] Castle Rocks, with deep sky viewing beginning sometime after 9 p.m. This is a chance to dig into some of the darkest skies in the west. Gary Leavitt, Secretary [email protected] Some members have already reserved campsites, but for those who are thinking of 208-731-7476 dropping by at the last minute, we have room for you at the bunkhouse, and would love to have to come by. Jim Tubbs, Treasurer / ALCOR [email protected] The following Saturday will be the regular MVAS meeting. Please check E-mail or 208-404-2999 Facebook for updates on our guest speaker that day. David Olsen, Newsletter Editor Until then, clear views, [email protected] Robert Mayer Rick Widmer, Webmaster [email protected] Magic Valley Astronomical Society is a member of the Astronomical League M-51 imaged by Rick Widmer & Ken Thomason Herrett Telescope Shotwell Camera https://herrett.csi.edu/astronomy/observatory/City_of_Rocks_Star_Party_2016.asp Calendars for August Sun Mon Tue Wed Thu Fri Sat 1 2 3 4 5 6 New Moon City Rocks City Rocks Lunation 1158 Castle Rocks Castle Rocks Star Party Star Party Almo, ID Almo, ID 7 8 9 10 11 12 13 MVAS General Mtg. -
Magnetism, Dynamo Action and the Solar-Stellar Connection
Living Rev. Sol. Phys. (2017) 14:4 DOI 10.1007/s41116-017-0007-8 REVIEW ARTICLE Magnetism, dynamo action and the solar-stellar connection Allan Sacha Brun1 · Matthew K. Browning2 Received: 23 August 2016 / Accepted: 28 July 2017 © The Author(s) 2017. This article is an open access publication Abstract The Sun and other stars are magnetic: magnetism pervades their interiors and affects their evolution in a variety of ways. In the Sun, both the fields themselves and their influence on other phenomena can be uncovered in exquisite detail, but these observations sample only a moment in a single star’s life. By turning to observa- tions of other stars, and to theory and simulation, we may infer other aspects of the magnetism—e.g., its dependence on stellar age, mass, or rotation rate—that would be invisible from close study of the Sun alone. Here, we review observations and theory of magnetism in the Sun and other stars, with a partial focus on the “Solar-stellar connec- tion”: i.e., ways in which studies of other stars have influenced our understanding of the Sun and vice versa. We briefly review techniques by which magnetic fields can be measured (or their presence otherwise inferred) in stars, and then highlight some key observational findings uncovered by such measurements, focusing (in many cases) on those that offer particularly direct constraints on theories of how the fields are built and maintained. We turn then to a discussion of how the fields arise in different objects: first, we summarize some essential elements of convection and dynamo theory, includ- ing a very brief discussion of mean-field theory and related concepts. -
You Every Step of The
with you Every Step of the Way 2016 ANNUAL REPORT $3.5M From the President TOTAL I am pleased to report that your Alumni Association is stronger and more focused than ever! As a result, we have had a greater impact on the Academy experience SUPPORT for our cadets, supporting their academic, athletic and leadership needs — every step of the way — throughout the entire Academy. TO CGA In the following pages, you will read the stories of five cadets whose lives have IN 2016 been touched by your generosity. Their stories are reflective of the impact of your support on all aspects of cadet life. From providing access to the best coaches, equipment and off-campus competitions that unite our cadets as teams and leaders, to investments in educational programs that build confidence and hone the necessary skills of command — it’s clear in the stories and smiles within, that your Alumni Association continues to define the Long Blue Line. This year, we chose to convey our financial success through the voices of these young men and women, but from the Alumni Association board and staff, let me be the voice of gratitude. Because of the generosity of donors to the Alumni Association, in 2016 we surpassed all previous support to the Academy — providing more than $3.5 million in fulfillment of our mission and goals. Nearly 5,000 donors helped us reach this total, 38% of which were alumni donors. Additionally, 35% of the donations received were given in support to the CGA Today! Fund, our area of greatest need. -
Arxiv:2105.11583V2 [Astro-Ph.EP] 2 Jul 2021 Keck-HIRES, APF-Levy, and Lick-Hamilton Spectrographs
Draft version July 6, 2021 Typeset using LATEX twocolumn style in AASTeX63 The California Legacy Survey I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades Lee J. Rosenthal,1 Benjamin J. Fulton,1, 2 Lea A. Hirsch,3 Howard T. Isaacson,4 Andrew W. Howard,1 Cayla M. Dedrick,5, 6 Ilya A. Sherstyuk,1 Sarah C. Blunt,1, 7 Erik A. Petigura,8 Heather A. Knutson,9 Aida Behmard,9, 7 Ashley Chontos,10, 7 Justin R. Crepp,11 Ian J. M. Crossfield,12 Paul A. Dalba,13, 14 Debra A. Fischer,15 Gregory W. Henry,16 Stephen R. Kane,13 Molly Kosiarek,17, 7 Geoffrey W. Marcy,1, 7 Ryan A. Rubenzahl,1, 7 Lauren M. Weiss,10 and Jason T. Wright18, 19, 20 1Cahill Center for Astronomy & Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA 2IPAC-NASA Exoplanet Science Institute, Pasadena, CA 91125, USA 3Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA 4Department of Astronomy, University of California Berkeley, Berkeley, CA 94720, USA 5Cahill Center for Astronomy & Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA 6Department of Astronomy & Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA 7NSF Graduate Research Fellow 8Department of Physics & Astronomy, University of California Los Angeles, Los Angeles, CA 90095, USA 9Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA 10Institute for Astronomy, University of Hawai`i, -
Détection Et Modélisation De Binaires Sismiques Avec Kepler
Frédéric MARCADON Détection et modélisation de binaires sismiques avec Kepler Directeur de thèse : Thierry APPOURCHAUX Institut d’Astrophysique Spatiale Orsay – 20 mars 2018 Introduction à l’astérosismologie Astérosismologie avec K2 Intérêt des étoiles binaires Introduction générale Missions CoRoT et Kepler : détection d’exoplanètes par la méthode des transits et caractérisation des étoiles hôtes par l’astérosismologie. Astérosismologie : outil de diagnostic de la structure interne des étoiles et de détermination de leurs propriétés physiques (masse et âge). Observation des variations de luminosité des étoiles au cours du temps par photométrie (courbes de lumière). Frédéric MARCADON Détection et modélisation de binaires sismiques avec Kepler 1 / 36 Introduction à l’astérosismologie Astérosismologie avec K2 Intérêt des étoiles binaires Sommaire 1 Introduction à l’astérosismologie 2 Astérosismologie avec K2 3 Intérêt des étoiles binaires 4 Binaires sismiques avec Kepler 5 Analyse orbitale de HD 188753 6 Modélisation de HD 188753 7 Conclusions et perspectives Frédéric MARCADON Détection et modélisation de binaires sismiques avec Kepler 2 / 36 Introduction à l’astérosismologie Astérosismologie avec K2 Intérêt des étoiles binaires Sommaire 1 Introduction à l’astérosismologie 2 Astérosismologie avec K2 3 Intérêt des étoiles binaires 4 Binaires sismiques avec Kepler 5 Analyse orbitale de HD 188753 6 Modélisation de HD 188753 7 Conclusions et perspectives Frédéric MARCADON Détection et modélisation de binaires sismiques avec Kepler 2 / 36 Introduction à l’astérosismologie Astérosismologie avec K2 Intérêt des étoiles binaires Théorie des oscillations stellaires Astérosismologie : étude des oscillations des étoiles permettant de sonder leur structure interne. Différents types d’ondes se propageant à l’intérieur de l’étoile : les ondes acoustiques générées dans la zone convective et dont la force de rappel est la pression (modes p). -
A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short). -
March 21–25, 2016
FORTY-SEVENTH LUNAR AND PLANETARY SCIENCE CONFERENCE PROGRAM OF TECHNICAL SESSIONS MARCH 21–25, 2016 The Woodlands Waterway Marriott Hotel and Convention Center The Woodlands, Texas INSTITUTIONAL SUPPORT Universities Space Research Association Lunar and Planetary Institute National Aeronautics and Space Administration CONFERENCE CO-CHAIRS Stephen Mackwell, Lunar and Planetary Institute Eileen Stansbery, NASA Johnson Space Center PROGRAM COMMITTEE CHAIRS David Draper, NASA Johnson Space Center Walter Kiefer, Lunar and Planetary Institute PROGRAM COMMITTEE P. Doug Archer, NASA Johnson Space Center Nicolas LeCorvec, Lunar and Planetary Institute Katherine Bermingham, University of Maryland Yo Matsubara, Smithsonian Institute Janice Bishop, SETI and NASA Ames Research Center Francis McCubbin, NASA Johnson Space Center Jeremy Boyce, University of California, Los Angeles Andrew Needham, Carnegie Institution of Washington Lisa Danielson, NASA Johnson Space Center Lan-Anh Nguyen, NASA Johnson Space Center Deepak Dhingra, University of Idaho Paul Niles, NASA Johnson Space Center Stephen Elardo, Carnegie Institution of Washington Dorothy Oehler, NASA Johnson Space Center Marc Fries, NASA Johnson Space Center D. Alex Patthoff, Jet Propulsion Laboratory Cyrena Goodrich, Lunar and Planetary Institute Elizabeth Rampe, Aerodyne Industries, Jacobs JETS at John Gruener, NASA Johnson Space Center NASA Johnson Space Center Justin Hagerty, U.S. Geological Survey Carol Raymond, Jet Propulsion Laboratory Lindsay Hays, Jet Propulsion Laboratory Paul Schenk,