Planetary System Dynamics Mathematics Tripos Part III / Part III Astrophysics
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RADIAL VELOCITIES in the ZODIACAL DUST CLOUD
A SURVEY OF RADIAL VELOCITIES in the ZODIACAL DUST CLOUD Brian Harold May Astrophysics Group Department of Physics Imperial College London Thesis submitted for the Degree of Doctor of Philosophy to Imperial College of Science, Technology and Medicine London · 2007 · 2 Abstract This thesis documents the building of a pressure-scanned Fabry-Perot Spectrometer, equipped with a photomultiplier and pulse-counting electronics, and its deployment at the Observatorio del Teide at Izaña in Tenerife, at an altitude of 7,700 feet (2567 m), for the purpose of recording high-resolution spectra of the Zodiacal Light. The aim was to achieve the first systematic mapping of the MgI absorption line in the Night Sky, as a function of position in heliocentric coordinates, covering especially the plane of the ecliptic, for a wide variety of elongations from the Sun. More than 250 scans of both morning and evening Zodiacal Light were obtained, in two observing periods – September-October 1971, and April 1972. The scans, as expected, showed profiles modified by components variously Doppler-shifted with respect to the unshifted shape seen in daylight. Unexpectedly, MgI emission was also discovered. These observations covered for the first time a span of elongations from 25º East, through 180º (the Gegenschein), to 27º West, and recorded average shifts of up to six tenths of an angstrom, corresponding to a maximum radial velocity relative to the Earth of about 40 km/s. The set of spectra obtained is in this thesis compared with predictions made from a number of different models of a dust cloud, assuming various distributions of dust density as a function of position and particle size, and differing assumptions about their speed and direction. -
Curriculum Vitae - 24 March 2020
Dr. Eric E. Mamajek Curriculum Vitae - 24 March 2020 Jet Propulsion Laboratory Phone: (818) 354-2153 4800 Oak Grove Drive FAX: (818) 393-4950 MS 321-162 [email protected] Pasadena, CA 91109-8099 https://science.jpl.nasa.gov/people/Mamajek/ Positions 2020- Discipline Program Manager - Exoplanets, Astro. & Physics Directorate, JPL/Caltech 2016- Deputy Program Chief Scientist, NASA Exoplanet Exploration Program, JPL/Caltech 2017- Professor of Physics & Astronomy (Research), University of Rochester 2016-2017 Visiting Professor, Physics & Astronomy, University of Rochester 2016 Professor, Physics & Astronomy, University of Rochester 2013-2016 Associate Professor, Physics & Astronomy, University of Rochester 2011-2012 Associate Astronomer, NOAO, Cerro Tololo Inter-American Observatory 2008-2013 Assistant Professor, Physics & Astronomy, University of Rochester (on leave 2011-2012) 2004-2008 Clay Postdoctoral Fellow, Harvard-Smithsonian Center for Astrophysics 2000-2004 Graduate Research Assistant, University of Arizona, Astronomy 1999-2000 Graduate Teaching Assistant, University of Arizona, Astronomy 1998-1999 J. William Fulbright Fellow, Australia, ADFA/UNSW School of Physics Languages English (native), Spanish (advanced) Education 2004 Ph.D. The University of Arizona, Astronomy 2001 M.S. The University of Arizona, Astronomy 2000 M.Sc. The University of New South Wales, ADFA, Physics 1998 B.S. The Pennsylvania State University, Astronomy & Astrophysics, Physics 1993 H.S. Bethel Park High School Research Interests Formation and Evolution -
Chapter 16 the Sun and Stars
Chapter 16 The Sun and Stars Stargazing is an awe-inspiring way to enjoy the night sky, but humans can learn only so much about stars from our position on Earth. The Hubble Space Telescope is a school-bus-size telescope that orbits Earth every 97 minutes at an altitude of 353 miles and a speed of about 17,500 miles per hour. The Hubble Space Telescope (HST) transmits images and data from space to computers on Earth. In fact, HST sends enough data back to Earth each week to fill 3,600 feet of books on a shelf. Scientists store the data on special disks. In January 2006, HST captured images of the Orion Nebula, a huge area where stars are being formed. HST’s detailed images revealed over 3,000 stars that were never seen before. Information from the Hubble will help scientists understand more about how stars form. In this chapter, you will learn all about the star of our solar system, the sun, and about the characteristics of other stars. 1. Why do stars shine? 2. What kinds of stars are there? 3. How are stars formed, and do any other stars have planets? 16.1 The Sun and the Stars What are stars? Where did they come from? How long do they last? During most of the star - an enormous hot ball of gas day, we see only one star, the sun, which is 150 million kilometers away. On a clear held together by gravity which night, about 6,000 stars can be seen without a telescope. -
A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?
geosciences Review A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What? José A. Caballero Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain; [email protected] Received: 23 August 2018; Accepted: 10 September 2018; Published: 28 September 2018 Abstract: “Free-floating, non-deuterium-burning, substellar objects” are isolated bodies of a few Jupiter masses found in very young open clusters and associations, nearby young moving groups, and in the immediate vicinity of the Sun. They are neither brown dwarfs nor planets. In this paper, their nomenclature, history of discovery, sites of detection, formation mechanisms, and future directions of research are reviewed. Most free-floating, non-deuterium-burning, substellar objects share the same formation mechanism as low-mass stars and brown dwarfs, but there are still a few caveats, such as the value of the opacity mass limit, the minimum mass at which an isolated body can form via turbulent fragmentation from a cloud. The least massive free-floating substellar objects found to date have masses of about 0.004 Msol, but current and future surveys should aim at breaking this record. For that, we may need LSST, Euclid and WFIRST. Keywords: planetary systems; stars: brown dwarfs; stars: low mass; galaxy: solar neighborhood; galaxy: open clusters and associations 1. Introduction I can’t answer why (I’m not a gangstar) But I can tell you how (I’m not a flam star) We were born upside-down (I’m a star’s star) Born the wrong way ’round (I’m not a white star) I’m a blackstar, I’m not a gangstar I’m a blackstar, I’m a blackstar I’m not a pornstar, I’m not a wandering star I’m a blackstar, I’m a blackstar Blackstar, F (2016), David Bowie The tenth star of George van Biesbroeck’s catalogue of high, common, proper motion companions, vB 10, was from the end of the Second World War to the early 1980s, and had an entry on the least massive star known [1–3]. -
Astr-Astronomy 1
ASTR-ASTRONOMY 1 ASTR 1116. Introduction to Astronomy Lab, Special ASTR-ASTRONOMY 1 Credit (1) This lab-only listing exists only for students who may have transferred to ASTR 1115G. Introduction Astro (lec+lab) NMSU having taken a lecture-only introductory astronomy class, to allow 4 Credits (3+2P) them to complete the lab requirement to fulfill the general education This course surveys observations, theories, and methods of modern requirement. Consent of Instructor required. , at some other institution). astronomy. The course is predominantly for non-science majors, aiming Restricted to Las Cruces campus only. to provide a conceptual understanding of the universe and the basic Prerequisite(s): Must have passed Introduction to Astronomy lecture- physics that governs it. Due to the broad coverage of this course, the only. specific topics and concepts treated may vary. Commonly presented Learning Outcomes subjects include the general movements of the sky and history of 1. Course is used to complete lab portion only of ASTR 1115G or ASTR astronomy, followed by an introduction to basic physics concepts like 112 Newton’s and Kepler’s laws of motion. The course may also provide 2. Learning outcomes are the same as those for the lab portion of the modern details and facts about celestial bodies in our solar system, as respective course. well as differentiation between them – Terrestrial and Jovian planets, exoplanets, the practical meaning of “dwarf planets”, asteroids, comets, ASTR 1120G. The Planets and Kuiper Belt and Trans-Neptunian Objects. Beyond this we may study 4 Credits (3+2P) stars and galaxies, star clusters, nebulae, black holes, and clusters of Comparative study of the planets, moons, comets, and asteroids which galaxies. -
Kinematics of Planet-Host Stars and Their Relation to Dynamical Streams in the Solar Neighbourhood
A&A 461, 171–182 (2007) Astronomy DOI: 10.1051/0004-6361:20065872 & c ESO 2006 Astrophysics Kinematics of planet-host stars and their relation to dynamical streams in the solar neighbourhood A. Ecuvillon1,G.Israelian1, F. Pont2,N.C.Santos2,3,4, and M. Mayor2 1 Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain e-mail: [email protected] 2 Observatoire de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland 3 Centro de Astronomia e Astrofisica de Universidade de Lisboa, Observatorio Astronomico de Lisboa, Tapada de Ajuda, 1349-018 Lisboa, Portugal 4 Centro de Geofisica de Évora, Rua Romaõ Ramalho 59, 7000 Évora, Portugal Received 21 June 2006 / Accepted 28 August 2006 ABSTRACT We present a detailed study on the kinematics of metal-rich stars with and without planets, and their relation to the Hyades, Sirius and Hercules dynamical streams in the solar neighbourhood. Accurate kinematics have been derived for all the stars belonging to the CORALIE planet search survey. We used precise radial velocity measurements and CCF parameters from the CORALIE database, and parallaxes, photometry and proper motions from the HIPPARCOS and Tycho-2 catalogues. The location of stars with planets in the thin or thick discs has been analysed using both kinematic and chemical constraints. We compare the kinematic behaviour of known planet-host stars to the remaining targets belonging to the volume-limited sample, in particular to its metal-rich population. The high average metallicity of the Hyades stream is confirmed. The planet-host targets show a kinematic behaviour similar to that of the metal-rich comparison subsample, rather than to that of the comparison sample as a whole, thus supporting a primordial origin for the metal excess observed in stars with known planetary companions. -
Kuiper Belt Dust Grains As a Source of Interplanetary Dust Particles
z( _R_:s124. 429-441) 11996) NASA-CR-2044q9 _RIIfI.E NO. 220 Kuiper Belt Dust Grains as a Source of Interplanetary Dust Particles JER-CHYI LzOU AND HERBERT A. ZOOK SN3, NASA Johnson Space Center, Houston, Texas 77058 E-mail: liou_'sn3.jsc.nasa.gov. AND STANLEYF. DERMOTT Department of Astronomy. University of Florida, Gainesuille, Florida 3261I Reccwed August 25. 1995: revised May 16. 1996 Solar System interplanetary space (e.g., Leinert and Grtin The recent discovery of the so-called Kuiper belt objects has 1990, Levasseur-Reeourd _" al. 1991 ). However, since the :,rompted the idea that these objects produce dust grains that discovery of the lirst Iran,-neptunian obiect (Jcw'ilt and :na_ contribute significantly to the interplanetary dust popula- Luu 1992. 1993) and the <ill ongoing discoveries of such uon. In this paper, the orbital evolution of dust grains, of objects (see Jewitt and Luu 1995 for an up-to-date sum- diameters 1 to 9 Jam, that originate in the region of the Kuiper mary), it has been proposed that small dust particles pro- belt is studied by means of direct numerical integration. Gravi- duced from these so-called "'Kuiper belt objects" may con- tational forces of the Sun and planets, solar radiation pressure, as well as Poynting-Robertson drag and solar wind drag are tribute significantly to the interplanetary dust population included. The interactions between charged dust grains and that constitutes the zodiacal cloud (e.g., Flynn 1994). They solar magnetic field are not considered in the model. Because may also be an important source of the interplanetary of the effects of drag forces, small dust grains will spiral toward dust particles (IDPs) collected in the stratosphere by high- the Sun once they are released from their large parent bodies. -
A Physically-Based Night Sky Model Henrik Wann Jensen1 Fredo´ Durand2 Michael M
To appear in the SIGGRAPH conference proceedings A Physically-Based Night Sky Model Henrik Wann Jensen1 Fredo´ Durand2 Michael M. Stark3 Simon Premozeˇ 3 Julie Dorsey2 Peter Shirley3 1Stanford University 2Massachusetts Institute of Technology 3University of Utah Abstract 1 Introduction This paper presents a physically-based model of the night sky for In this paper, we present a physically-based model of the night sky realistic image synthesis. We model both the direct appearance for image synthesis, and demonstrate it in the context of a Monte of the night sky and the illumination coming from the Moon, the Carlo ray tracer. Our model includes the appearance and illumi- stars, the zodiacal light, and the atmosphere. To accurately predict nation of all significant sources of natural light in the night sky, the appearance of night scenes we use physically-based astronomi- except for rare or unpredictable phenomena such as aurora, comets, cal data, both for position and radiometry. The Moon is simulated and novas. as a geometric model illuminated by the Sun, using recently mea- The ability to render accurately the appearance of and illumi- sured elevation and albedo maps, as well as a specialized BRDF. nation from the night sky has a wide range of existing and poten- For visible stars, we include the position, magnitude, and temper- tial applications, including film, planetarium shows, drive and flight ature of the star, while for the Milky Way and other nebulae we simulators, and games. In addition, the night sky as a natural phe- use a processed photograph. Zodiacal light due to scattering in the nomenon of substantial visual interest is worthy of study simply for dust covering the solar system, galactic light, and airglow due to its intrinsic beauty. -
Zodiacal Cloud Complexes
Earth Planets Space, 50, 465–471, 1998 Zodiacal Cloud Complexes Ingrid Mann MPI fur¨ Aeronomie, D-37191 Katlenburg-Lindau, Germany (Received October 7, 1997; Revised March 17, 1998; Accepted March 17, 1998) We discuss some aspects of the study of the Zodiacal cloud based on brightness observations. The discussion of optical properties as well as the spatial distribution of the dust cloud show that the description of the dust cloud as a homogeneous cloud is reasonable for the regions near the Earth orbit, but fails in the description of the dust in the inner solar system. The reasons for this are that different components of the dust cloud may have different types of orbital evolution depending on the parameters of their initial orbits. Also the collisional evolution of dust in the inner solar system may have some influence. As far as perspectives for future observations are concerned, the study of Doppler shifts of the Fraunhofer lines in the Zodiacal light will provide further knowledge about the orbital distribution of dust particles, as well as advanced infrared observations will help towards a better understanding of the outer solar system dust cloud beyond the asteroid belt. 1. Introduction properties per volume element. A common method of data Small bodies in our solar system cover a broad size range analysis applies forward calculations of the line of sight inte- from asteroids and comets to dust particles of micrometer gral under reasonable assumptions about particle properties size and below. Brightness observations do mainly cover a and spatial distribution. Detailed descriptions of the line of range of particles of 1 to 100 micron in size, i.e. -
The Three-Dimensional Structure of the Zodiacal Dust Bands
ICARUS 127, 461±484 (1997) ARTICLE NO. IS975704 The Three-Dimensional Structure of the Zodiacal Dust Bands William T. Reach Universities Space Research Association and NASA Goddard Space Flight Center, Code 685, Greenbelt, Maryland 20771, and Institut d'Astrophysique Spatiale, BaÃtiment 121, Universite Paris XI, 91405 Orsay Cedex, France E-mail: [email protected] Bryan A. Franz General Sciences Corporation, NASA Goddard Space Flight Center, Code 970.1, Greenbelt, Maryland 20771 and Janet L. Weiland Hughes STX, NASA Goddard Space Flight Center, Code 685.9, Greenbelt, Maryland 20771 Received July 18, 1996; revised January 2, 1997 model, the dust is distributed among the asteroid family mem- Using observations of the infrared sky brightness by the bers with the same distributions of proper orbital inclination Cosmic Background Explorer (COBE)1 Diffuse Infrared Back- and semimajor axis but a random ascending node. In the mi- ground Experiment (DIRBE) and Infrared Astronomical Satel- grating model, particles are presumed to be under the in¯uence lite (IRAS), we have created maps of the surface brightness of Poynting±Robertson drag, so that they are distributed Fourier-®ltered to suppress the smallest (, 18) structures and throughout the inner Solar System. The migrating model is the large-scale background (.158). Dust bands associated with better able to match the parallactic variation of dust-band lati- the Themis, Koronis, and Eos families are readily evident. A tude as well as the 12- to 60-mm spectrum of the dust bands. dust band associated with the Maria family is also present. The The annual brightness variations can be explained only by the parallactic distances to the emitting regions of the Koronis, migrating model. -
The Quest for the Gegenschein Erwin Matys, Karoline Mrazek
The Quest for the Gegenschein Erwin Matys, Karoline Mrazek The sun’s counterglow — or gegenschein — is kind of a stargazers’ legend. Every amateur astronomer has heard about it, only a few of them have actually seen it, and even fewer were lucky enough to capture an image of this dim and ghostlike apparition. As a fellow observer put it: “The gegenschein is certainly not a GOTO-object.” Matter of fact, it isn’t an object at all. But let’s start from the beginning. What exactly is the gegenschein? It is widely known that the space between the planets isn’t empty. The plane of the solar system is filled with an enormous disk of small dust particles with sizes ranging from less than 1/1000 mm up to 1 mm. It is less commonly known that this interplanetary dust cloud is a highly dynamic structure. In contrast to conventional wisdom, it is not an aeon-old leftover from the solar system’s formation. This primordial dust is long gone. Today’s interplanetary dust is — in an astronomical sense of speaking — very young, only millions of years old. Most of the particles originate from quite recent incidents, like asteroid collisions. This is not the gegenschein. The picture shows the zodiacal light, which is closely related to the gegenschein. Here imaged from a rural site, the zodiacal light is a cone of light extending from the sun along the ecliptic, visible after dusk and before dawn. The gegenschein stems from the same dust cloud, but is much harder to detect or photograph. -
The Kuiper Belt: What We Know and What We Don’T
The Kuiper Belt: What We Know and What We Don’t David Jewitt, UCLA, September 2012 The best indication of the significance of the Kuiper belt lies in its multiple connections to other aspects of the Solar system. The dust in the Zodiacal cloud, the rocks in the meteor streams, the nuclei of comets, the Centaurs, perhaps also the irregular moons of the planets and the Trojans that lead and trail planets in their orbits, are all related to the parent population in the Kuiper belt. Further afield, the dusty debris disks of other stars are likely produced by collisional shattering of parent bodies in unseen Kuiper belts about them. Because of these many connections, Kuiper belt science has already had significant impact on the study of the contents, origin and evolution of the Solar system, and on understanding the Solar system in the context set by other stars. While we know much more than we used to, we still don’t know many things about the Kuiper belt. The Solar system formed from a flattened, rotating disk of gas and dust, itself produced by gravitational collapse from the interstellar medium. The explosion of a nearby massive star, a “supernova”, may have provided the initial compression causing the cloud to collapse, as suggested by the products of decay of short-lived radioactive elements (esp. 26Al) embedded in meteorites (Lee et al. 1977, Dauphas and Chaussidon 2011). Planets formed quickly in the dense inner portions of this disk but the process of growth in the rarefied outer regions was very slow.