The H and G Magnitude System for Asteroids
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Commission 27 of the Iau Information Bulletin
COMMISSION 27 OF THE I.A.U. INFORMATION BULLETIN ON VARIABLE STARS Nos. 2401 - 2500 1983 September - 1984 March EDITORS: B. SZEIDL AND L. SZABADOS, KONKOLY OBSERVATORY 1525 BUDAPEST, Box 67, HUNGARY HU ISSN 0374-0676 CONTENTS 2401 A POSSIBLE CATACLYSMIC VARIABLE IN CANCER Masaaki Huruhata 20 September 1983 2402 A NEW RR-TYPE VARIABLE IN LEO Masaaki Huruhata 20 September 1983 2403 ON THE DELTA SCUTI STAR BD +43d1894 A. Yamasaki, A. Okazaki, M. Kitamura 23 September 1983 2404 IQ Vel: IMPROVED LIGHT-CURVE PARAMETERS L. Kohoutek 26 September 1983 2405 FLARE ACTIVITY OF EPSILON AURIGAE? I.-S. Nha, S.J. Lee 28 September 1983 2406 PHOTOELECTRIC OBSERVATIONS OF 20 CVn Y.W. Chun, Y.S. Lee, I.-S. Nha 30 September 1983 2407 MINIMUM TIMES OF THE ECLIPSING VARIABLES AH Cep AND IU Aur Pavel Mayer, J. Tremko 4 October 1983 2408 PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR EV Lac IN 1980 G. Asteriadis, S. Avgoloupis, L.N. Mavridis, P. Varvoglis 6 October 1983 2409 HD 37824: A NEW VARIABLE STAR Douglas S. Hall, G.W. Henry, H. Louth, T.R. Renner 10 October 1983 2410 ON THE PERIOD OF BW VULPECULAE E. Szuszkiewicz, S. Ratajczyk 12 October 1983 2411 THE UNIQUE DOUBLE-MODE CEPHEID CO Aur E. Antonello, L. Mantegazza 14 October 1983 2412 FLARE STARS IN TAURUS A.S. Hojaev 14 October 1983 2413 BVRI PHOTOMETRY OF THE ECLIPSING BINARY QX Cas Thomas J. Moffett, T.G. Barnes, III 17 October 1983 2414 THE ABSOLUTE MAGNITUDE OF AZ CANCRI William P. Bidelman, D. Hoffleit 17 October 1983 2415 NEW DATA ABOUT THE APSIDAL MOTION IN THE SYSTEM OF RU MONOCEROTIS D.Ya. -
Phases of Venus and Galileo
Galileo and the phases of Venus I) Periods of Venus 1) Synodical period and phases The synodic period1 of Venus is 584 days The superior2 conjunction occured on 11 may 1610. Calculate the date of the quadrature, of the inferior conjunction and of the next superior conjunction, supposing the motions of the Earth and Venus are circular and uniform. In fact the next superior conjunction occured on 11 december 1611 and inferior conjunction on 26 february 1611. 2) Sidereal period The sidereal period of the Earth is 365.25 days. Calculate the sidereal period of Venus. II) Phases on Venus in geo and heliocentric models 1) Phases in differents models 1) Determine the phases of Venus in geocentric models, where the Earth is at the center of the universe and planets orbit around (Venus “above” or “below” the sun) * Pseudo-Aristoteles model : Earth (center)-Moon-Sun-Mercury-Venus-Mars-Jupiter-Saturne * Ptolemeo’s model : Earth (center)-Moon-Mercury-Venus-Sun-Mars-Jupiter-Saturne 2) Determine the phases of Venus in the heliocentric model, where planets orbit around the sun. Copernican system : Sun (center)-Mercury-Venus-Earth-Mars-Jupiter-Saturne 2) Observations of Galileo Galileo (1564-1642) observed Venus in 1610-1611 with a telescope. Read the letters of Galileo. May we conclude that the Copernican model is the only one available ? When did Galileo begins to observe Venus? Give the approximate dates of the quadrature and of the inferior conjunction? What are the approximate dates of the 5 observations of Galileo supposing the figure from the Essayer, was drawn in 1610-1611 1 The synodic period is the time that it takes for the object to reappear at the same point in the sky, relative to the Sun, as observed from Earth; i.e. -
The Dunhuang Chinese Sky: a Comprehensive Study of the Oldest Known Star Atlas
25/02/09JAHH/v4 1 THE DUNHUANG CHINESE SKY: A COMPREHENSIVE STUDY OF THE OLDEST KNOWN STAR ATLAS JEAN-MARC BONNET-BIDAUD Commissariat à l’Energie Atomique ,Centre de Saclay, F-91191 Gif-sur-Yvette, France E-mail: [email protected] FRANÇOISE PRADERIE Observatoire de Paris, 61 Avenue de l’Observatoire, F- 75014 Paris, France E-mail: [email protected] and SUSAN WHITFIELD The British Library, 96 Euston Road, London NW1 2DB, UK E-mail: [email protected] Abstract: This paper presents an analysis of the star atlas included in the medieval Chinese manuscript (Or.8210/S.3326), discovered in 1907 by the archaeologist Aurel Stein at the Silk Road town of Dunhuang and now held in the British Library. Although partially studied by a few Chinese scholars, it has never been fully displayed and discussed in the Western world. This set of sky maps (12 hour angle maps in quasi-cylindrical projection and a circumpolar map in azimuthal projection), displaying the full sky visible from the Northern hemisphere, is up to now the oldest complete preserved star atlas from any civilisation. It is also the first known pictorial representation of the quasi-totality of the Chinese constellations. This paper describes the history of the physical object – a roll of thin paper drawn with ink. We analyse the stellar content of each map (1339 stars, 257 asterisms) and the texts associated with the maps. We establish the precision with which the maps are drawn (1.5 to 4° for the brightest stars) and examine the type of projections used. -
Galaxies – AS 3011
Galaxies – AS 3011 Simon Driver [email protected] ... room 308 This is a Junior Honours 18-lecture course Lectures 11am Wednesday & Friday Recommended book: The Structure and Evolution of Galaxies by Steven Phillipps Galaxies – AS 3011 1 Aims • To understand: – What is a galaxy – The different kinds of galaxy – The optical properties of galaxies – The hidden properties of galaxies such as dark matter, presence of black holes, etc. – Galaxy formation concepts and large scale structure • Appreciate: – Why galaxies are interesting, as building blocks of the Universe… and how simple calculations can be used to better understand these systems. Galaxies – AS 3011 2 1 from 1st year course: • AS 1001 covered the basics of : – distances, masses, types etc. of galaxies – spectra and hence dynamics – exotic things in galaxies: dark matter and black holes – galaxies on a cosmological scale – the Big Bang • in AS 3011 we will study dynamics in more depth, look at other non-stellar components of galaxies, and introduce high-redshift galaxies and the large-scale structure of the Universe Galaxies – AS 3011 3 Outline of lectures 1) galaxies as external objects 13) large-scale structure 2) types of galaxy 14) luminosity of the Universe 3) our Galaxy (components) 15) primordial galaxies 4) stellar populations 16) active galaxies 5) orbits of stars 17) anomalies & enigmas 6) stellar distribution – ellipticals 18) revision & exam advice 7) stellar distribution – spirals 8) dynamics of ellipticals plus 3-4 tutorials 9) dynamics of spirals (questions set after -
The Solar System
5 The Solar System R. Lynne Jones, Steven R. Chesley, Paul A. Abell, Michael E. Brown, Josef Durech,ˇ Yanga R. Fern´andez,Alan W. Harris, Matt J. Holman, Zeljkoˇ Ivezi´c,R. Jedicke, Mikko Kaasalainen, Nathan A. Kaib, Zoran Kneˇzevi´c,Andrea Milani, Alex Parker, Stephen T. Ridgway, David E. Trilling, Bojan Vrˇsnak LSST will provide huge advances in our knowledge of millions of astronomical objects “close to home’”– the small bodies in our Solar System. Previous studies of these small bodies have led to dramatic changes in our understanding of the process of planet formation and evolution, and the relationship between our Solar System and other systems. Beyond providing asteroid targets for space missions or igniting popular interest in observing a new comet or learning about a new distant icy dwarf planet, these small bodies also serve as large populations of “test particles,” recording the dynamical history of the giant planets, revealing the nature of the Solar System impactor population over time, and illustrating the size distributions of planetesimals, which were the building blocks of planets. In this chapter, a brief introduction to the different populations of small bodies in the Solar System (§ 5.1) is followed by a summary of the number of objects of each population that LSST is expected to find (§ 5.2). Some of the Solar System science that LSST will address is presented through the rest of the chapter, starting with the insights into planetary formation and evolution gained through the small body population orbital distributions (§ 5.3). The effects of collisional evolution in the Main Belt and Kuiper Belt are discussed in the next two sections, along with the implications for the determination of the size distribution in the Main Belt (§ 5.4) and possibilities for identifying wide binaries and understanding the environment in the early outer Solar System in § 5.5. -
194 Publications of the Measurements of The
194 PUBLICATIONS OF THE MEASUREMENTS OF THE RADIATION FROM THE PLANET MERCURY By Edison Pettit and Seth Β. Nicholson The total radiation from Mercury and its transmission through a water cell and through a microscope cover glass were measured with the thermocouple at the 60-inch reflector on June 17, 1923, and again at the 100-inch reflector on June 21st. Since the thermocouple is compensated for general diffuse radiation it is possible to measure the radiation from stars and planets in full daylight quite as well as at night (aside from the effect of seeing), and in the present instance Mercury and the comparison stars were observed near the meridian between th hours of 9 a. m. and 1 p. m. The thermocouple cell is provided with a rock salt window 2 mm thick obtained from the Smithsonian Institution through the kindness of Dr. Abbot. The transmission curves for the water cell and microscope cover glass have been carefully de- termined : those for the former may be found in Astrophysical Journal, 56, 344, 1922; those for the latter, together with the curves for rock salt, fluorite and the atmosphere for average observing conditions are given in Figure 1. We may consider the water cell to transmit in the region of 0.3/a to 1.3/x and the covér glass to transmit between 0.3μ and 5.5/1,, although some radiation is transmitted by the cover glass up to 7.5/a. The atmosphere acts as a screen transmitting prin- cipally in two regions 0.3μ, to 2,5μ and 8μ to 14μ, respectively. -
The University of Chicago Glimpses of Far Away
THE UNIVERSITY OF CHICAGO GLIMPSES OF FAR AWAY PLACES: INTENSIVE ATMOSPHERE CHARACTERIZATION OF EXTRASOLAR PLANETS A DISSERTATION SUBMITTED TO THE FACULTY OF THE DIVISION OF THE PHYSICAL SCIENCES IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF ASTRONOMY AND ASTROPHYSICS BY LAURA KREIDBERG CHICAGO, ILLINOIS AUGUST 2016 Copyright c 2016 by Laura Kreidberg All Rights Reserved Far away places with strange sounding names Far away over the sea Those far away places with strange sounding names Are calling, calling me. { Joan Whitney & Alex Kramer TABLE OF CONTENTS LIST OF FIGURES . vii LIST OF TABLES . ix ACKNOWLEDGMENTS . x ABSTRACT . xi 1 INTRODUCTION . 1 1.1 Exoplanets' Greatest Hits, 1995 - present . 1 1.2 Moving from Discovery to Characterization . 2 1.2.1 Clues from Planetary Atmospheres I: How Do Planets Form? . 2 1.2.2 Clues from Planetary Atmospheres II: What are Planets Like? . 3 1.2.3 Goals for This Work . 4 1.3 Overview of Atmosphere Characterization Techniques . 4 1.3.1 Transmission Spectroscopy . 5 1.3.2 Emission Spectroscopy . 5 1.4 Technical Breakthroughs Enabling Atmospheric Studies . 7 1.5 Chapter Summaries . 10 2 CLOUDS IN THE ATMOSPHERE OF THE SUPER-EARTH EXOPLANET GJ 1214b . 12 2.1 Introduction . 12 2.2 Observations and Data Reduction . 13 2.3 Implications for the Atmosphere . 14 2.4 Conclusions . 18 3 A PRECISE WATER ABUNDANCE MEASUREMENT FOR THE HOT JUPITER WASP-43b . 21 3.1 Introduction . 21 3.2 Observations and Data Reduction . 23 3.3 Analysis . 24 3.4 Results . 27 3.4.1 Constraints from the Emission Spectrum . -
A Magnetar Model for the Hydrogen-Rich Super-Luminous Supernova Iptf14hls Luc Dessart
A&A 610, L10 (2018) https://doi.org/10.1051/0004-6361/201732402 Astronomy & © ESO 2018 Astrophysics LETTER TO THE EDITOR A magnetar model for the hydrogen-rich super-luminous supernova iPTF14hls Luc Dessart Unidad Mixta Internacional Franco-Chilena de Astronomía (CNRS, UMI 3386), Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile e-mail: [email protected] Received 2 December 2017 / Accepted 14 January 2018 ABSTRACT Transient surveys have recently revealed the existence of H-rich super-luminous supernovae (SLSN; e.g., iPTF14hls, OGLE-SN14-073) that are characterized by an exceptionally high time-integrated bolometric luminosity, a sustained blue optical color, and Doppler- broadened H I lines at all times. Here, I investigate the effect that a magnetar (with an initial rotational energy of 4 × 1050 erg and 13 field strength of 7 × 10 G) would have on the properties of a typical Type II supernova (SN) ejecta (mass of 13.35 M , kinetic 51 56 energy of 1:32 × 10 erg, 0.077 M of Ni) produced by the terminal explosion of an H-rich blue supergiant star. I present a non-local thermodynamic equilibrium time-dependent radiative transfer simulation of the resulting photometric and spectroscopic evolution from 1 d until 600 d after explosion. With the magnetar power, the model luminosity and brightness are enhanced, the ejecta is hotter and more ionized everywhere, and the spectrum formation region is much more extended. This magnetar-powered SN ejecta reproduces most of the observed properties of SLSN iPTF14hls, including the sustained brightness of −18 mag in the R band, the blue optical color, and the broad H I lines for 600 d. -
Evolution of Thermally Pulsing Asymptotic Giant Branch Stars
The Astrophysical Journal, 822:73 (15pp), 2016 May 10 doi:10.3847/0004-637X/822/2/73 © 2016. The American Astronomical Society. All rights reserved. EVOLUTION OF THERMALLY PULSING ASYMPTOTIC GIANT BRANCH STARS. V. CONSTRAINING THE MASS LOSS AND LIFETIMES OF INTERMEDIATE-MASS, LOW-METALLICITY AGB STARS* Philip Rosenfield1,2,7, Paola Marigo2, Léo Girardi3, Julianne J. Dalcanton4, Alessandro Bressan5, Benjamin F. Williams4, and Andrew Dolphin6 1 Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA 2 Department of Physics and Astronomy G. Galilei, University of Padova, Vicolo dell’Osservatorio 3, I-35122 Padova, Italy 3 Osservatorio Astronomico di Padova—INAF, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy 4 Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA 5 Astrophysics Sector, SISSA, Via Bonomea 265, I-34136 Trieste, Italy 6 Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756, USA Received 2016 January 1; accepted 2016 March 14; published 2016 May 6 ABSTRACT Thermally pulsing asymptotic giant branch (TP-AGB) stars are relatively short lived (less than a few Myr), yet their cool effective temperatures, high luminosities, efficient mass loss, and dust production can dramatically affect the chemical enrichment histories and the spectral energy distributions of their host galaxies. The ability to accurately model TP-AGB stars is critical to the interpretation of the integrated light of distant galaxies, especially in redder wavelengths. We continue previous efforts to constrain the evolution and lifetimes of TP-AGB stars by modeling their underlying stellar populations. Using Hubble Space Telescope (HST) optical and near-infrared photometry taken of 12 fields of 10 nearby galaxies imaged via the Advanced Camera for Surveys Nearby Galaxy Survey Treasury and the near-infrared HST/SNAP follow-up campaign, we compare the model and observed TP- AGB luminosity functions as well as the ratio of TP-AGB to red giant branch stars. -
Absolute-Magnitude Calibration for W Uma-Type Systems. II. in Uence Of
AbsoluteMagnitude Calibration for W UMatype Systems I I Inuence of Metallicity 1 Slavek Rucinski Longb ow Drive Scarb orough Ontario MW W Canada March ABSTRACT A mo dication to the absolute magnitude calibration for W UMatype systems taking into account dierences in metal abundances is derived on the basis of contact binary systems recently discovered in metalp o or clusters A preliminary estimate of the magnitude of the metallicitydependent term for the B V based calibration is M F eH The calibration based on the V I color is V C exp ected to b e less sensitive with the correction term F eH Need for a metallicitydependent term in the calibration Searches for gravitational microlenses are currently giving large numbers of serendipitously discovered variable stars Among these variables there are many W UMatype contact binaries On the basis of the rst part of the catalog of variable stars discovered during the OGLE pro ject Udalski et al one can estimate the total number of contact binaries which will b e discovered in the Baade Window during OGLE at well over one thousand This estimate is based on discoveries of such systems in the rst part of the catalog which covered one of the OGLE elds ie less than of the whole area searched the Central Baade Window BWC and reached I The newly discovered systems will provide excellent statistics for the p erio d color and amplitude distributions of contact binaries much b etter than those based on the skyeld sample which is heavily biased towards largeamplitude variables Kaluzny -
Absolute Magnitude and Slope Parameter G Calibration of Asteroid 25143 Itokawa
Meteoritics & Planetary Science 44, Nr 12, 1849–1852 (2009) Abstract available online at http://meteoritics.org Absolute magnitude and slope parameter G calibration of asteroid 25143 Itokawa Fabrizio BERNARDI1, 2*, Marco MICHELI1, and David J. THOLEN1 1Institute for Astronomy, University of Hawai‘i, 2680 Woodlawn Drive, Honolulu, Hawai‘i 96822, USA 2Dipartimento di Matematica, Università di Pisa, Largo Pontecorvo 5, 56127 Pisa, Italy *Corresponding author. E-mail: [email protected] (Received 12 December 2008; revision accepted 27 May 2009) Abstract–We present results from an observing campaign of 25143 Itokawa performed with the 2.2 m telescope of the University of Hawai‘i between November 2000 and September 2001. The main goal of this paper is to determine the absolute magnitude H and the slope parameter G of the phase function with high accuracy for use in determining the geometric albedo of Itokawa. We found a value of H = 19.40 and a value of G = 0.21. INTRODUCTION empirical relation between a polarization curve and the albedo. Our work will take advantage by the post-encounter The present work was performed as part of our size determination obtained by Hayabusa, allowing a more collaboration with NASA to support the space mission direct conversion of the ground-based photometric Hayabusa (MUSES-C), which in September 2005 had a information into a physically meaningful value for the albedo. rendezvous with the near-Earth asteroid 25143 Itokawa. We Another important goal of these observations was to used the 2.2 m telescope of the University of Hawai‘i at collect more data for a possible future detection of the Mauna Kea. -
PHAS 1102 Physics of the Universe 3 – Magnitudes and Distances
PHAS 1102 Physics of the Universe 3 – Magnitudes and distances Brightness of Stars • Luminosity – amount of energy emitted per second – not the same as how much we observe! • We observe a star’s apparent brightness – Depends on: • luminosity • distance – Brightness decreases as 1/r2 (as distance r increases) • other dimming effects – dust between us & star Defining magnitudes (1) Thus Pogson formalised the magnitude scale for brightness. This is the brightness that a star appears to have on the sky, thus it is referred to as apparent magnitude. Also – this is the brightness as it appears in our eyes. Our eyes have their own response to light, i.e. they act as a kind of filter, sensitive over a certain wavelength range. This filter is called the visual band and is centred on ~5500 Angstroms. Thus these are apparent visual magnitudes, mv Related to flux, i.e. energy received per unit area per unit time Defining magnitudes (2) For example, if star A has mv=1 and star B has mv=6, then 5 mV(B)-mV(A)=5 and their flux ratio fA/fB = 100 = 2.512 100 = 2.512mv(B)-mv(A) where !mV=1 corresponds to a flux ratio of 1001/5 = 2.512 1 flux(arbitrary units) 1 6 apparent visual magnitude, mv From flux to magnitude So if you know the magnitudes of two stars, you can calculate mv(B)-mv(A) the ratio of their fluxes using fA/fB = 2.512 Conversely, if you know their flux ratio, you can calculate the difference in magnitudes since: 2.512 = 1001/5 log (f /f ) = [m (B)-m (A)] log 2.512 10 A B V V 10 = 102/5 = 101/2.5 mV(B)-mV(A) = !mV = 2.5 log10(fA/fB) To calculate a star’s apparent visual magnitude itself, you need to know the flux for an object at mV=0, then: mS - 0 = mS = 2.5 log10(f0) - 2.5 log10(fS) => mS = - 2.5 log10(fS) + C where C is a constant (‘zero-point’), i.e.