Comets, Asteroids and Zodiacal Light As Seen by ISO ∗
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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. -
Space in Central and Eastern Europe
EU 4+ SPACE IN CENTRAL AND EASTERN EUROPE OPPORTUNITIES AND CHALLENGES FOR THE EUROPEAN SPACE ENDEAVOUR Report 5, September 2007 Charlotte Mathieu, ESPI European Space Policy Institute Report 5, September 2007 1 Short Title: ESPI Report 5, September 2007 Editor, Publisher: ESPI European Space Policy Institute A-1030 Vienna, Schwarzenbergplatz 6 Austria http://www.espi.or.at Tel.: +43 1 718 11 18 - 0 Fax - 99 Copyright: ESPI, September 2007 This report was funded, in part, through a contract with the EUROPEAN SPACE AGENCY (ESA). Rights reserved - No part of this report may be reproduced or transmitted in any form or for any purpose without permission from ESPI. Citations and extracts to be published by other means are subject to mentioning “source: ESPI Report 5, September 2007. All rights reserved” and sample transmission to ESPI before publishing. Price: 11,00 EUR Printed by ESA/ESTEC Compilation, Layout and Design: M. A. Jakob/ESPI and Panthera.cc Report 5, September 2007 2 EU 4+ Executive Summary ....................................................................................... 5 Introduction…………………………………………………………………………………………7 Part I - The New EU Member States Introduction................................................................................................... 9 1. What is really at stake for Europe? ....................................................... 10 1.1. The European space community could benefit from a further cooperation with the ECS ................................................................. 10 1.2. However, their economic weight remains small in the European landscape and they still suffer from organisatorial and funding issues .... 11 1.2.1. Economic weight of the ECS in Europe ........................................... 11 1.2.2. Reality of their impact on competition ............................................ 11 1.2.3. Foreign policy issues ................................................................... 12 1.2.4. Internal challenges ..................................................................... 12 1.3. -
(704) Interamnia from Its Occultations and Lightcurves
International Journal of Astronomy and Astrophysics, 2014, 4, 91-118 Published Online March 2014 in SciRes. http://www.scirp.org/journal/ijaa http://dx.doi.org/10.4236/ijaa.2014.41010 A 3-D Shape Model of (704) Interamnia from Its Occultations and Lightcurves Isao Satō1*, Marc Buie2, Paul D. Maley3, Hiromi Hamanowa4, Akira Tsuchikawa5, David W. Dunham6 1Astronomical Society of Japan, Yamagata, Japan 2Southwest Research Institute, Boulder, USA 3International Occultation Timing Association, Houston, USA 4Hamanowa Astronomical Observatory, Fukushima, Japan 5Yanagida Astronomical Observatory, Ishikawa, Japan 6International Occultation Timing Association, Greenbelt, USA Email: *[email protected], [email protected], [email protected], [email protected], [email protected], [email protected] Received 9 November 2013; revised 9 December 2013; accepted 17 December 2013 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract A 3-D shape model of the sixth largest of the main belt asteroids, (704) Interamnia, is presented. The model is reproduced from its two stellar occultation observations and six lightcurves between 1969 and 2011. The first stellar occultation was the occultation of TYC 234500183 on 1996 De- cember 17 observed from 13 sites in the USA. An elliptical cross section of (344.6 ± 9.6 km) × (306.2 ± 9.1 km), for position angle P = 73.4 ± 12.5˚ was fitted. The lightcurve around the occulta- tion shows that the peak-to-peak amplitude was 0.04 mag. and the occultation phase was just be- fore the minimum. -
Surface Composition of Icy Asteroids and the Special Case of Ceres
Surface composition of icy asteroids and the special case of Ceres P. Vernazza (Laboratoire d’Astrophysique de Marseille) March 15, 2017 SOFIA Tele-Talk Examples of asteroids with Compositional links between asteroids and meteorites meteoritic analogues Falls Mass in the asteroid belt 6.2% 9.6% 80.0% 8.4% 1.9% 1.0% 1.1% 0.4% 2.5% 0.1% 1.5% 7.0% 4.6% 3.3% Total Total ~98% ~30% Vernazza & Beck 2016 ~2/3 of the mass of the asteroid belt seems absent from our meteorite collections 6 asteroid types, representing ~2/3 of the main belt mass (DeMeo & Carry 2013), are presently unconnected to meteorites. Asteroid spectral properties (DeMeo et al. 2009) Metamorphosed CI/CM chondrites as analogues of most B, C, Cb, Cg types? (1) Metamorphosed CI/CM chondrites as analogues of most B, C, Cb, Cg types? (2) This is very unlikely because: a) Metamorphosed CI/CM chondrites represent 0.2% of the falls whereas B, C, Cb and Cg type represent ~50% of the mass of the belt b) Metamorphosed CI/CM chondrites possess a significantly higher density (2.5-3 g/cm3) than those asteroid types (0.8-1.5 g/cm3) c) Metamorphosed CI/CM chondrites possess different spectral properties in the mid-infrared with respect to those asteroid types Why are most B, C, Cb, Cg, P and D types unsampled by our meteorite collections? The lack of samples for these objects within our collections may stem from the fact that they are volatile-rich as implied by their low density (0.8-2 g/cm3) and their comet-like activity in some cases. -
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. -
Accurate Positions of Pluto and Asteroids Observed in Bucharest During the Year 1932
ACCURATE POSITIONS OF PLUTO AND ASTEROIDS OBSERVED IN BUCHAREST DURING THE YEAR 1932 GHEORGHE BOCŞA, PETRE POPESCU, MIHAELA LICULESCU Astronomical Institute of the Romanian Academy Str. Cuţitul de Argint 5, 040557 Bucharest, Romania E-mail: [email protected] Abstract. The paper contains the observations of minor planets performed in Bucharest Astronomical Observatory in the year 1932 with the 380/6000 mm astrograph. Both Turner’s (constants) and Schlesinger’s (dependences) methods were used in the computation of the normal coordinates of the objects. Keywords: photographic astrometry – minor planets. 1. INTRODUCTION The article is a continuation of the complete investigation of Bucharest Wide-Field Plates Archive initiated in 2010; it contains the plates with asteroids observed in 1932. That year 185 plates were exposed and were stored in the archive, but were not reduced. After analysing them, 98 plates were detected to contain measurable minor planets. The first observed positions in this year were of planet Pluto. They were exposed on 1318cm plates, with 52 minutes exposure .The observations were performed by the famous Romanian astronomer Professor Gheorghe Demetrescu. The most difficult problem was the identification of the planet, the three plates obtained in 1932 having dozens of stars with up to 15 magnitudes. As all the observations were performed in the same month and the planet did not have a great proper motion, it was possible to superpose two plates and to identify Pluto. The values (O–C)α and (O–C)δ were calculated by M. Svechnikov from the Institute of Applied Astronomy in Sankt Petersburg on the basis of precise positions obtained in Bucharest, which we integrated in Pluto’s orbit. -
Lunar Occultations 2021
Milky Way, Whiteside, MO July 7, 2018 References: http://www.seasky.org/astronomy/astronomy-calendar-2021.html http://www.asteroidoccultation.com/2021-BestEvents.htm https://in-the-sky.org/newscalyear.php?year=2021&maxdiff=7 https://www.go-astronomy.com/solar-system/event-calendar.htm https://www.photopills.com/articles/astronomical-events-photography- guide#step1 https://www.timeanddate.com/eclipse/ All Photos by Mark Jones Unless noted Southern Cross May 6, 2018 Tulum, MX Full Moon Events 2021 Largest Apr 27 2021: diameter: 33.7’; 345,572km May 26, 2021: diameter: 33.4’; 358,014km; Eclipse Smallest Oct 20, 2021: diameter: 29.7’; 402,517km; Eclipse Image below shows the apparent size difference between largest and smallest dates Canon DSLR FL=300mm Full Moon Events 2021 May 26 – Lunar Eclipse- partial from STL Partial Start 4:23am, Alt=9 deg moon set 5:43am, 80% covered Aug 22 - Blue Moon Nov 19 – Lunar Eclipse – Almost total from STL Partial Start 1:19am, Alt=61 deg Max Partial 3:05am, Alt=42 deg Partial End 4:49am, Alt=23 deg Total Lunar Eclipse, Oct 8 2014 Canon DSLR, Celestron C-8 Other Moon Events 2021 V Lunar-X on the Moon (Start Times) • Mar 20 – 16:01 Alt=54° • May 18 – 17:34 Alt=65° • Jul 16 – 17:00 Alt=42° • Sep 13 – 16:09 Alt=15° X • Nov 11 – 18:03 Alt=32° Lunar V also seen at same Sun angles Yellow=Favorable Moon Conditions Other Moon Events 2021 Lunar V - Visible at the same time just north of the X. -
Iván Almár Is Professor of Astronomy at the Konkoly Observatory of the Hungarian Academy of Sciences
Iván Almár is professor of astronomy at the Konkoly Observatory of the Hungarian Academy of Sciences. He has worked in space research (specifically, upper-atmospheric research and satellite geodesy) for more than 50 years. Prof. Almár has been a Member of the IAA since 1984, and was chairman of its Space and Society Commission from 2003 to 2005. He began presenting and publishing papers on planetary protection in 1989. Charles Cockell is professor of geomicrobiology at the Open University, UK. He obtained his PhD from the University of Oxford and held an NRC Associateship at the NASA Ames Research Centre. His interests are in microbe-mineral interactions and life in extreme environments. He is author of several books, including 'Space on Earth' (Macmillan), which explores the links between environmentalism and space exploration. His publications on ethics have focused on the place of microorganisms in environmental ethics and the protection of the space environment. He is Chair of the Earth and Space Foundation. Catharine A. Conley has served as the NASA Planetary Protection Officer since 2006. Prior to this, Conley's research at NASA Ames Research Center focused on the biochemistry and evolution of muscle tissue. Conley has been involved in several spaceflight experiments using the nematode worm, Caenorhabditis elegans, the first of which was flown on the last mission of the Space Shuttle Columbia. Flight hardware was recovered after the tragic accident, and when opened it was found that some spaceflown experimental animals were still alive, a finding of considerable relevance to Planetary Protection. Gernot Groemer has a background in astronomy and astrobiology. -
Sciences, Is the Discovery of Twenty-Two Minor Planets Commonly Known As the Watson Asteriods
ASTRONOMY: A. O. LEUSCHNER 67 ADMISSIONS TO SICK REPORT-Concluded UNITED STATES NUMBERS opFr White Colored INTERNA- TIONAL CLASSIFICA- Mean strength..................................................... 545,518 13,150 TIONT Causes of admission to sick report Ratio perstrength1000 of mean 00-02, 07,15, 16,24- 27,29- 31,49, 57,58, 60,61, Traumatisms, others ............................... 9.14 10.04 63-65, 70-72, 74,76- 78,82- 84,97- 99 80 Sunstroke.. 0.04 0.08 Total for diseases................................. 882.51 1064.41 Total for external causes.. 91.69 90.42 Grand total................... ................ 974.19 1154.83 PERTURBATIONS AND TABLES OF THE MINOR PLANETS DISCOVERED BY JAMES C. WATSON BY ARMIN 0. LEUSCHNER BERKELEY ASTRONOMICAL DEPARTMENT, UNIVERSITY OF CALIFORNIA Read before the Academy, April 16, 1916 Among the many important contributions to Astronomical Science by James C. Watson, one of the original members of the National Academy of Sciences, is the discovery of twenty-two minor planets commonly known as the Watson asteriods. The first of these, (79) Eurynome, was discovered at Ann Arbor on September 14, 1863, and the last, (179) Klytaemnestra, on November 11, 1877, three years before his death. By his will a fund was bequeathed in trust to the National Academy of Sciences for the purpose of promoting astronomical research. One of the objects specifically designated was the construction of tables of the perturbations of the minor planets dis- covered by the testator. From the beginning Prof. Simon Newcomb was a Downloaded by guest on September 30, 2021 68 ASTRONOMY: A. O. LEUSCHNER member of the board of Watson Trustees; later he became chairman of the board, and remained in that capacity on the board until his death in 1908, being succeeded by Prof. -
Stellar Flares with ARIEL
Stellar flares with ARIEL Krisztián Vida & Bálint Seli Konkoly Observatory, Budapest, Hungary Stellar activity as noise ● Photospheric starspots have small contribution to light variations in the IR regime ● Flares are also more prominent at shorter wavelengths Flare of an M-dwarf in multiple passbands ● A possible problem: with transit spectroscopy the removed spectral source is the whole stellar disk, but different activity contribution can cause contamination even in IR regime Rackham, Apai, Giampapa 2018 ● A possible problem: with transit spectroscopy the removed spectral source is the whole stellar disk, but different activity contribution can cause contamination even in IR regime ● This can reach a level of 10+% depending on wavelength and spot confguration Rackham, Apai, Giampapa 2018 ARIEL & stellar activity ● Magnetic activity is an important property of young, fast-rotating stars ● This can have serious consequences on their exoplanets What remains to study for later stages of star/planetary system evolution? Rotation (age) vs. X-ray luminosity ARIEL & stellar activity ● Magnetic activity is an important property of young, fast-rotating stars ● This can have serious consequences on their exoplanets ● Some models already exist discussing the effects of activity on planets, but not much is known on the additive effects and observational confrmation is also missing Model of the atmospheric changes of an Earth-like planet due to a large fare event (Segura et al. 2010) ARIEL & stellar activity ● The interaction of exoplanets and stellar magnetism is crucial for planetary evolution and for the search for life ● Can the system harbor life on long term? (frst signs of life on Eearth dates back to 4Gyr, although complex life based on eukaryotic cells took much longer time to form) ARIEL & stellar activity High resolution photometry can be crucial for fast transients – e.g. -
Hydrated Minerals on Asteroids: the Astronomical Record
Hydrated Minerals on Asteroids: The Astronomical Record A. S. Rivkin, E. S. Howell, F. Vilas, and L. A. Lebofsky March 28, 2002 Corresponding Author: Andrew Rivkin MIT 54-418 77 Massachusetts Ave. Cambridge MA, 02139 [email protected] 1 1 Abstract Knowledge of the hydrated mineral inventory on the asteroids is important for deducing the origin of Earth’s water, interpreting the meteorite record, and unraveling the processes occurring during the earliest times in solar system history. Reflectance spectroscopy shows absorption features in both the 0.6-0.8 and 2.5-3.5 pm regions, which are diagnostic of or associated with hydrated minerals. Observations in those regions show that hydrated minerals are common in the mid-asteroid belt, and can be found in unex- pected spectral groupings, as well. Asteroid groups formerly associated with mineralogies assumed to have high temperature formation, such as MAand E-class asteroids, have been observed to have hydration features in their reflectance spectra. Some asteroids have apparently been heated to several hundred degrees Celsius, enough to destroy some fraction of their phyllosili- cates. Others have rotational variation suggesting that heating was uneven. We summarize this work, and present the astronomical evidence for water- and hydroxyl-bearing minerals on asteroids. 2 Introduction Extraterrestrial water and water-bearing minerals are of great importance both for understanding the formation and evolution of the solar system and for supporting future human activities in space. The presence of water is thought to be one of the necessary conditions for the formation of life as 2 we know it.