Astronomy Without a Telescope
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CENTAURI II Benutzerhandbuch
CENTAURI II Benutzerhandbuch SW-Version ab 3.1.0.73 MAYAH, CENTAURI, FLASHCAST sind eingetragene Warenzeichen. Alle anderen verwendeten Warenzeichen werden hiermit anerkannt. CENTAURI II Benutzerhandbuch ab SW 3.1.0.73 Bestell-Nr. CIIUM001 Stand 11/2005 (c) Copyright by MAYAH Communications GmbH Die Vervielfältigung des vorliegenden Handbuches, sowie der darin besprochenen Dokumentationen aus dem Internet, auch nur auszugsweise, ist nur mit ausdrücklicher schriftlicher Genehmigung der MAYAH Communications GmbH erlaubt. 1 Einführung ........................................................................................................... 1 1.1 Vorwort......................................................................................................... 1 1.2 Einbau / Installation ...................................................................................... 2 1.3 Lieferumfang ................................................................................................ 2 1.4 Umgebungs- / Betriebsbedingung................................................................ 2 1.5 Anschlüsse................................................................................................... 3 2 Verbindungsaufbau ............................................................................................. 4 2.1 ISDN Verbindungen mit dem Centauri II ...................................................... 4 2.1.1 FlashCast Technologie und Audiocodec Kategorien............................. 4 2.1.2 Wie bekomme ich eine synchronisierte Verbindung -
Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born. -
Durham E-Theses
Durham E-Theses First visibility of the lunar crescent and other problems in historical astronomy. Fatoohi, Louay J. How to cite: Fatoohi, Louay J. (1998) First visibility of the lunar crescent and other problems in historical astronomy., Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/996/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk me91 In the name of Allah, the Gracious, the Merciful >° 9 43'' 0' eji e' e e> igo4 U61 J CO J: lic 6..ý v Lo ý , ý.,, "ý J ýs ýºý. ur ý,r11 Lýi is' ý9r ZU LZJE rju No disaster can befall on the earth or in your souls but it is in a book before We bring it into being; that is easy for Allah. In order that you may not grieve for what has escaped you, nor be exultant at what He has given you; and Allah does not love any prideful boaster. -
Binocular Universe: Sly Fox September 2010 Phil Harrington
Binocular Universe is available every month on Cloudynights.com Binocular Universe: Sly Fox September 2010 Phil Harrington ast month's Stellafane convention, held atop Breezy Hill outside of Springfield, Vermont, was the best in recent memory. The skies were the Lclearest we've had in years, giving us a chance to enjoy the beauty of the summer Milky Way, which stretched from horizon to horizon. Armed with my trusty 10x50 and 16x70 binoculars, I sat back in my reclining chair and swept the plane of our Galaxy in pursuit of some old friends and new conquests. Above: Summer star map from Star Watch by Phil Harrington Binocular Universe is available every month on Cloudynights.com Above: Finder chart for this month's Binocular Universe. Chart adapted from Touring the Universe through Binoculars Atlas (TUBA), www.philharrington.net/tuba.htm Binocular Universe is available every month on Cloudynights.com Here are a few gems I bumped into along the way as I viewed the tiny constellation of Vulpecula the Fox. Vulpecula is a faint summertime constellation wedged between Cygnus (the Swan) to the north and Sagitta (the Arrow) to the south. None of Vulpecula’s stars shine brighter than magnitude 4.5, so seeing a fox here is a tall order indeed. But the sly Fox holds many binocular treasures for those who the time to seek them out. Vulpecula was created in 1687 by the Polish astronomer Johannes Hevelius. His original drawing showed a small fox carrying a hapless goose in its mouth. He called the combination Vulpecula et Anser ("the little fox and the goose"). -
A Hot Subdwarf-White Dwarf Super-Chandrasekhar Candidate
A hot subdwarf–white dwarf super-Chandrasekhar candidate supernova Ia progenitor Ingrid Pelisoli1,2*, P. Neunteufel3, S. Geier1, T. Kupfer4,5, U. Heber6, A. Irrgang6, D. Schneider6, A. Bastian1, J. van Roestel7, V. Schaffenroth1, and B. N. Barlow8 1Institut fur¨ Physik und Astronomie, Universitat¨ Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, D-14476 Potsdam-Golm, Germany 2Department of Physics, University of Warwick, Coventry, CV4 7AL, UK 3Max Planck Institut fur¨ Astrophysik, Karl-Schwarzschild-Straße 1, 85748 Garching bei Munchen¨ 4Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA 5Texas Tech University, Department of Physics & Astronomy, Box 41051, 79409, Lubbock, TX, USA 6Dr. Karl Remeis-Observatory & ECAP, Astronomical Institute, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Sternwartstr. 7, 96049 Bamberg, Germany 7Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA 8Department of Physics and Astronomy, High Point University, High Point, NC 27268, USA *[email protected] ABSTRACT Supernova Ia are bright explosive events that can be used to estimate cosmological distances, allowing us to study the expansion of the Universe. They are understood to result from a thermonuclear detonation in a white dwarf that formed from the exhausted core of a star more massive than the Sun. However, the possible progenitor channels leading to an explosion are a long-standing debate, limiting the precision and accuracy of supernova Ia as distance indicators. Here we present HD 265435, a binary system with an orbital period of less than a hundred minutes, consisting of a white dwarf and a hot subdwarf — a stripped core-helium burning star. -
Breakthrough Propulsion Study Assessing Interstellar Flight Challenges and Prospects
Breakthrough Propulsion Study Assessing Interstellar Flight Challenges and Prospects NASA Grant No. NNX17AE81G First Year Report Prepared by: Marc G. Millis, Jeff Greason, Rhonda Stevenson Tau Zero Foundation Business Office: 1053 East Third Avenue Broomfield, CO 80020 Prepared for: NASA Headquarters, Space Technology Mission Directorate (STMD) and NASA Innovative Advanced Concepts (NIAC) Washington, DC 20546 June 2018 Millis 2018 Grant NNX17AE81G_for_CR.docx pg 1 of 69 ABSTRACT Progress toward developing an evaluation process for interstellar propulsion and power options is described. The goal is to contrast the challenges, mission choices, and emerging prospects for propulsion and power, to identify which prospects might be more advantageous and under what circumstances, and to identify which technology details might have greater impacts. Unlike prior studies, the infrastructure expenses and prospects for breakthrough advances are included. This first year's focus is on determining the key questions to enable the analysis. Accordingly, a work breakdown structure to organize the information and associated list of variables is offered. A flow diagram of the basic analysis is presented, as well as more detailed methods to convert the performance measures of disparate propulsion methods into common measures of energy, mass, time, and power. Other methods for equitable comparisons include evaluating the prospects under the same assumptions of payload, mission trajectory, and available energy. Missions are divided into three eras of readiness (precursors, era of infrastructure, and era of breakthroughs) as a first step before proceeding to include comparisons of technology advancement rates. Final evaluation "figures of merit" are offered. Preliminary lists of mission architectures and propulsion prospects are provided. -
The Observer's Handbook for 1912
T he O bservers H andbook FOR 1912 PUBLISHED BY THE ROYAL ASTRONOMICAL SOCIETY OF CANADA E d i t e d b y C. A, CHANT FOURTH YEAR OF PUBLICATION TORONTO 198 C o l l e g e St r e e t Pr in t e d fo r t h e So c ie t y 1912 T he Observers Handbook for 1912 PUBLISHED BY THE ROYAL ASTRONOMICAL SOCIETY OF CANADA TORONTO 198 C o l l e g e St r e e t Pr in t e d fo r t h e S o c ie t y 1912 PREFACE Some changes have been made in the Handbook this year which, it is believed, will commend themselves to observers. In previous issues the times of sunrise and sunset have been given for a small number of selected places in the standard time of each place. On account of the arbitrary correction which must be made to the mean time of any place in order to get its standard time, the tables given for a particualar place are of little use any where else, In order to remedy this the times of sunrise and sunset have been calculated for places on five different latitudes covering the populous part of Canada, (pages 10 to 21), while the way to use these tables at a large number of towns and cities is explained on pages 8 and 9. The other chief change is in the addition of fuller star maps near the end. These are on a large enough scale to locate a star or planet or comet when its right ascension and declination are given. -
Wynyard Planetarium & Observatory a Autumn Observing Notes
Wynyard Planetarium & Observatory A Autumn Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn Tour of the Sky with the Naked Eye CASSIOPEIA Look for the ‘W’ 4 shape 3 Polaris URSA MINOR Notice how the constellations swing around Polaris during the night Pherkad Kochab Is Kochab orange compared 2 to Polaris? Pointers Is Dubhe Dubhe yellowish compared to Merak? 1 Merak THE PLOUGH Figure 1: Sketch of the northern sky in autumn. © Rob Peeling, CaDAS, 2007 version 1.2 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. Close to the horizon is a group of stars like the outline of a saucepan with the handle stretching to your left. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The two right-hand stars are called the Pointers. Can you tell that the higher of the two, Dubhe is slightly yellowish compared to the lower, Merak? Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white- hot. 2. Use the Pointers to guide you upwards to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the left are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris. -
A Spectroscopic Study of the Scorpio-Centaurus Association
PranllQa. Vol. 7, No.3, 1976, pp 160-\ 80. © Prmted in India. A spectroscopic study of the Scorpio-Centaurus association R RAJAMOHAN Indian Institute of Astrophysics, Bangaiore 560034 MS recehcl 5 April 1976 • I' Abstract. Rotational .... elocities as well as hydrogen and he Jlum Ine I'ntensities of .' have been one hundred. and twelve members of the Scorplo-Centaurus aSSOclatlO~ . b h derived. For stars with M~ < 0'0, the distribution of rotational velocitieS of °lt are SJlnlar the upper Scorplus subgroup and the upper Centaurus-Lupus Su b grou P 1 . I and closely resemble those of the field stars. Stars with M, > O' 0, all of w lie 1 are found in th.e dense upper Scorpius region, rotate much faster than their counter parts amongst field stars, the Pleiades and Alpha-Persei cluster members. The measured equivalent width of H'Y for 77 stars provide a distance nlOd~\U~ of 6·0±0·09 magnitudes for the association. Evolutionary effects in the del1;~e hydrogen line intensities are found between the two subgroups. The hydrogen- me intensities at all spectral types in the upper Centaurus-Lupus subgroup are systematically smaller than thOse of members in the upper Scorpius subgrouP. Analysis of high dispersion spectra of five members of the association y.ield a helium abundance of Nae(N. = 0·096 ± 0 004. Along with data available In the literature, the mean helium abundance of thirteen stars of this association is found to be 0·098 :±: O· 004 by number. For the two main subgroups of this association, we deflve a value of 0 105 ± 0 001 for the upper Centaurus-Lupus group from three stars and 0·096 ± 0·005 for the upper Scorpius group from ten stars. -
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). -
Not Surprising That the Method Begins to Break Down at This Point
152 ASTRONOMY: W. S. ADAMS hanced lines in the early F stars are normally so prominent that it is not surprising that the method begins to break down at this point. To illustrate the use of the formulae and curves we may select as il- lustrations a few stars of different spectral types and magnitudes. These are collected in Table II. The classification is from Mount Wilson determinations. TABLE H ~A M PARAIuAX srTATYP_________________ (a) I(b) (C) (a) (b) c) Mean Comp. Ob. Pi 10U96.... 7.6F5 -0.7 +0.7 +3.0 +6.5 4.7 5.8 5.7 +0#04 +0.04 Sun........ GO -0.5 +0.5 +3.0 +5.6 4.3 5.8 5.2 Lal. 38287.. 7.2 G5 -1.8 +1.5 +3.5 +7.4 +6.3 +6.2 7.3 +0.10 +0.09 a Arietis... 2.2K0O +2.5 -2.4 +0.2 +1.0 1.3 +0.2 0.8 +0.05 +0.09 aTauri.... 1.1K5 +3.0 -2.0 +0.5 -0.4 +1.9 +0.5 0.7 +0.08 +0.07 61' Cygni...6.3K8 -1.8 +5.8 +7.7 +8.2 9.3 8.9 8.8 +0.32 +0.31 Groom. 34..8.2 Ma -2.2 +6.8 +9.2 +10.2 10.5 10.4 10.4 +0.28 +0.28 The parallaxes are computed from the absolute magnitudes by the formula, to which reference has already been made, 5 logr = M - m - 5. The results are given in the next to the last column of the table, and the measured parallaxes in the final column. -
Variable Star Classification and Light Curves Manual
Variable Star Classification and Light Curves An AAVSO course for the Carolyn Hurless Online Institute for Continuing Education in Astronomy (CHOICE) This is copyrighted material meant only for official enrollees in this online course. Do not share this document with others. Please do not quote from it without prior permission from the AAVSO. Table of Contents Course Description and Requirements for Completion Chapter One- 1. Introduction . What are variable stars? . The first known variable stars 2. Variable Star Names . Constellation names . Greek letters (Bayer letters) . GCVS naming scheme . Other naming conventions . Naming variable star types 3. The Main Types of variability Extrinsic . Eclipsing . Rotating . Microlensing Intrinsic . Pulsating . Eruptive . Cataclysmic . X-Ray 4. The Variability Tree Chapter Two- 1. Rotating Variables . The Sun . BY Dra stars . RS CVn stars . Rotating ellipsoidal variables 2. Eclipsing Variables . EA . EB . EW . EP . Roche Lobes 1 Chapter Three- 1. Pulsating Variables . Classical Cepheids . Type II Cepheids . RV Tau stars . Delta Sct stars . RR Lyr stars . Miras . Semi-regular stars 2. Eruptive Variables . Young Stellar Objects . T Tau stars . FUOrs . EXOrs . UXOrs . UV Cet stars . Gamma Cas stars . S Dor stars . R CrB stars Chapter Four- 1. Cataclysmic Variables . Dwarf Novae . Novae . Recurrent Novae . Magnetic CVs . Symbiotic Variables . Supernovae 2. Other Variables . Gamma-Ray Bursters . Active Galactic Nuclei 2 Course Description and Requirements for Completion This course is an overview of the types of variable stars most commonly observed by AAVSO observers. We discuss the physical processes behind what makes each type variable and how this is demonstrated in their light curves. Variable star names and nomenclature are placed in a historical context to aid in understanding today’s classification scheme.