Hipparchus' Coordinate System
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Scienza E Cultura Universitalia
SCIENZA E CULTURA UNIVERSITALIA Costantino Sigismondi (ed.) ORBE NOVUS Astronomia e Studi Gerbertiani 1 Universitalia SIGISMONDI, Costantino (a cura di) Orbe Novus / Costantino Sigismondi Roma : Universitalia, 2010 158 p. ; 24 cm. – ( Scienza e Cultura ) ISBN … 1. Storia della Scienza. Storia della Chiesa. I. Sigismondi, Costantino. 509 – SCIENZE PURE, TRATTAMENTO STORICO 270 – STORIA DELLA CHIESA In copertina: Imago Gerberti dal medagliere capitolino e scritta ORBE NOVVS nell'epitaffio tombale di Silvestro II a S. Giovanni in Laterano (entrambe le foto sono di Daniela Velestino). Collana diretta da Rosalma Salina Borello e Luca Nicotra Prima edizione: maggio 2010 Universitalia INTRODUZIONE Introduzione Costantino Sigismondi L’edizione del convegno gerbertiano del 2009, in pieno anno internazionale dell’astronomia, si è tenuta nella Basilica di S. Maria degli Angeli e dei Martiri il 12 maggio, e a Seoul presso l’università Sejong l’11 giugno 2009. La scelta della Basilica è dovuta alla presenza della grande meridiana voluta dal papa Clemente XI Albani nel 1700, che ancora funziona e consente di fare misure di valore astrometrico. Il titolo di questi atti, ORBE NOVUS, è preso, come i precedenti, dall’epitaffio tombale di Silvestro II in Laterano, e vuole suggerire il legame con il “De Revolutionibus Orbium Coelestium” di Copernico, sebbene il contesto in cui queste parole sono tratte vuole inquadrare Gerberto nel suo ministero petrino come il nuovo pastore per tutto il mondo: UT FIERET PASTOR TOTO ORBE NOVVS. Elizabeth Cavicchi del Massachussets Institute of Technology, ha riflettuto sulle esperienze di ottica geometrica fatte da Gerberto con i tubi, nel contesto contemporaneo dello sviluppo dell’ottica nel mondo arabo con cui Gerberto era stato in contatto. -
Aquarius Aries Pisces Taurus
Zodiac Constellation Cards Aquarius Pisces January 21 – February 20 – February 19 March 20 Aries Taurus March 21 – April 21 – April 20 May 21 Zodiac Constellation Cards Gemini Cancer May 22 – June 22 – June 21 July 22 Leo Virgo July 23 – August 23 – August 22 September 23 Zodiac Constellation Cards Libra Scorpio September 24 – October 23 – October 22 November 22 Sagittarius Capricorn November 23 – December 23 – December 22 January 20 Zodiac Constellations There are 12 zodiac constellations that form a belt around the earth. This belt is considered special because it is where the sun, the moon, and the planets all move. The word zodiac means “circle of figures” or “circle of life”. As the earth revolves around the sun, different parts of the sky become visible. Each month, one of the 12 constellations show up above the horizon in the east and disappears below the horizon in the west. If you are born under a particular sign, the constellation it is named for can’t be seen at night. Instead, the sun is passing through it around that time of year making it a daytime constellation that you can’t see! Aquarius Aries Cancer Capricorn Gemini Leo January 21 – March 21 – June 22 – December 23 – May 22 – July 23 – February 19 April 20 July 22 January 20 June 21 August 22 Libra Pisces Sagittarius Scorpio Taurus Virgo September 24 – February 20 – November 23 – October 23 – April 21 – August 23 – October 22 March 20 December 22 November 22 May 21 September 23 1. Why is the belt that the constellations form around the earth special? 2. -
The Zodiac: Comparison of the Ancient Greek Mythology and the Popular Romanian Beliefs
THE ZODIAC: COMPARISON OF THE ANCIENT GREEK MYTHOLOGY AND THE POPULAR ROMANIAN BELIEFS DOINA IONESCU *, FLORA ROVITHIS ** , ELENI ROVITHIS-LIVANIOU *** Abstract : This paper intends to draw a comparison between the ancient Greek Mythology and the Romanian folk beliefs for the Zodiac. So, after giving general information for the Zodiac, each one of the 12 zodiac signs is described. Besides, information is given for a few astronomical subjects of special interest, together with Romanian people believe and the description of Greek myths concerning them. Thus, after a thorough examination it is realized that: a) The Greek mythology offers an explanation for the consecration of each Zodiac sign, and even if this seems hyperbolic in almost most of the cases it was a solution for things not easily understood at that time; b) All these passed to the Romanians and influenced them a lot firstly by the ancient Greeks who had built colonies in the present Romania coasts as well as via commerce, and later via the Romans, and c) The Romanian beliefs for the Zodiac is also connected to their deep Orthodox religious character, with some references also to their history. Finally, a general discussion is made and some agricultural and navigator suggestions connected to Pleiades and Hyades are referred, too. Keywords : Zodiac, Greek, mythology, tradition, religion. PROLOGUE One of their first thoughts, or questions asked, by the primitive people had possibly to do with sky and stars because, when during the night it was very dark, all these lights above had certainly arose their interest. So, many ancient civilizations observed the stars as well as their movements in the sky. -
Equatorial and Cartesian Coordinates • Consider the Unit Sphere (“Unit”: I.E
Coordinate Transforms Equatorial and Cartesian Coordinates • Consider the unit sphere (“unit”: i.e. declination the distance from the center of the (δ) sphere to its surface is r = 1) • Then the equatorial coordinates Equator can be transformed into Cartesian coordinates: right ascension (α) – x = cos(α) cos(δ) – y = sin(α) cos(δ) z x – z = sin(δ) y • It can be much easier to use Cartesian coordinates for some manipulations of geometry in the sky Equatorial and Cartesian Coordinates • Consider the unit sphere (“unit”: i.e. the distance y x = Rcosα from the center of the y = Rsinα α R sphere to its surface is r = 1) x Right • Then the equatorial Ascension (α) coordinates can be transformed into Cartesian coordinates: declination (δ) – x = cos(α)cos(δ) z r = 1 – y = sin(α)cos(δ) δ R = rcosδ R – z = sin(δ) z = rsinδ Precession • Because the Earth is not a perfect sphere, it wobbles as it spins around its axis • This effect is known as precession • The equatorial coordinate system relies on the idea that the Earth rotates such that only Right Ascension, and not declination, is a time-dependent coordinate The effects of Precession • Currently, the star Polaris is the North Star (it lies roughly above the Earth’s North Pole at δ = 90oN) • But, over the course of about 26,000 years a variety of different points in the sky will truly be at δ = 90oN • The declination coordinate is time-dependent albeit on very long timescales • A precise astronomical coordinate system must account for this effect Equatorial coordinates and equinoxes • To account -
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. -
Earth-Centred Universe
Earth-centred Universe The fixed stars appear on the celestial sphere Earth rotates in one sidereal day The solar day is longer by about 4 minutes → scattered sunlight obscures the stars by day The constellations are historical → learn to recognise: Ursa Major, Ursa Minor, Cassiopeia, Pegasus, Auriga, Gemini, Orion, Taurus Sun’s Motion in the Sky The Sun moves West to East against the background of Stars Stars Stars stars Us Us Us Sun Sun Sun z z z Start 1 sidereal day later 1 solar day later Compared to the stars, the Sun takes on average 3 min 56.5 sec extra to go round once The Sun does not travel quite at a constant speed, making the actual length of a solar day vary throughout the year Pleiades Stars near the Sun Sun Above the atmosphere: stars seen near the Sun by the SOHO probe Shield Sun in Taurus Image: Hyades http://sohowww.nascom.nasa.g ov//data/realtime/javagif/gifs/20 070525_0042_c3.gif Constellations Figures courtesy: K & K From The Beauty of the Heavens by C. F. Blunt (1842) The Celestial Sphere The celestial sphere rotates anti-clockwise looking north → Its fixed points are the north celestial pole and the south celestial pole All the stars on the celestial equator are above the Earth’s equator How high in the sky is the pole star? It is as high as your latitude on the Earth Motion of the Sky (animated ) Courtesy: K & K Pole Star above the Horizon To north celestial pole Zenith The latitude of Northern horizon Aberdeen is the angle at 57º the centre of the Earth A Earth shown in the diagram as 57° 57º Equator Centre The pole star is the same angle above the northern horizon as your latitude. -
Astronomy and Astrology
Astronomy and Astrology Philippe Zarka CNRS & Observatoire de Paris, France Daniel Kunth CNRS- I.A.P, France 1. Introduction : what is astrology ? 2. Astrology & Society 3. Astrology & Astronomy 4. Astrology & Science 5. Conclusion : the success of Astrology and the role of Science • References 1. Introduction : what is astrology ? 2. Astrology & Society 3. Astrology & Astronomy 4. Astrology & Science 5. Conclusion : the success of Astrology and the role of Science • References The influence of celestial bodies on Earth has several obvious manifestations : life on Earth depends on the Sun, seasons are linked to its position in the sky (due to the non–perpendicularity of the Earth’s rotation axis with respect to the ecliptic plane), … Seasons … ocean tides are controlled by the position of the Moon (via its differential gravitation) and of the Sun, and eclipses are due to Sun–Moon–Earth alignments. Solar eclipse High/Low tides Astrology extrapolates these factual influences by postulating that the positions of the Sun, Moon and 8 planets* other than Earth (hereafter the « luminars ») with respect to the sky background, as well as with respect to each other, influence terrestrial events and human psychology and destiny. *wandering celestial bodies Apparent trajectory of Mars as seen from Earth, and explanation The position of luminars is considered - relative to the tropical zodiac, defined by Hipparchus* : 12 « signs » dividing in 30° sectors the band of constellations upon which the motions of the Sun and planets are projected during the year, with an arbitrary origin at the vernal – spring – equinox (γ), and - relative to the « houses », a local reference frame dividing the local sky in 12 sectors. -
Trajectory Coordinate System Information We Have Calculated the New Horizons Trajectory and Full State Vector Information in 11 Different Coordinate Systems
Trajectory Coordinate System Information We have calculated the New Horizons trajectory and full state vector information in 11 different coordinate systems. Below we describe the coordinate systems, and in the next section we describe the trajectory file format. Heliographic Inertial (HGI) This system is Sun centered with the X-axis along the intersection line of the ecliptic (zero longitude occurs at the +X-axis) and solar equatorial planes. The Z-axis is perpendicular to the solar equator, and the Y-axis completes the right-handed system. This coordinate system is also referred to as the Heliocentric Inertial (HCI) system. Heliocentric Aries Ecliptic Date (HAE-DATE) This coordinate system is heliocentric system with the Z-axis normal to the ecliptic plane and the X-axis pointes toward the first point of Aries on the Vernal Equinox, and the Y- axis completes the right-handed system. This coordinate system is also referred to as the Solar Ecliptic (SE) coordinate system. The word “Date” refers to the time at which one defines the Vernal Equinox. In this case the date observation is used. Heliocentric Aries Ecliptic J2000 (HAE-J2000) This coordinate system is heliocentric system with the Z-axis normal to the ecliptic plane and the X-axis pointes toward the first point of Aries on the Vernal Equinox, and the Y- axis completes the right-handed system. This coordinate system is also referred to as the Solar Ecliptic (SE) coordinate system. The label “J2000” refers to the time at which one defines the Vernal Equinox. In this case it is defined at the J2000 date, which is January 1, 2000 at noon. -
Abd Al-Rahman Al-Sufi and His Book of the Fixed Stars: a Journey of Re-Discovery
ResearchOnline@JCU This file is part of the following reference: Hafez, Ihsan (2010) Abd al-Rahman al-Sufi and his book of the fixed stars: a journey of re-discovery. PhD thesis, James Cook University. Access to this file is available from: http://eprints.jcu.edu.au/28854/ The author has certified to JCU that they have made a reasonable effort to gain permission and acknowledge the owner of any third party copyright material included in this document. If you believe that this is not the case, please contact [email protected] and quote http://eprints.jcu.edu.au/28854/ 5.1 Extant Manuscripts of al-Ṣūfī’s Book Al-Ṣūfī’s ‘Book of the Fixed Stars’ dating from around A.D. 964, is one of the most important medieval Arabic treatises on astronomy. This major work contains an extensive star catalogue, which lists star co-ordinates and magnitude estimates, as well as detailed star charts. Other topics include descriptions of nebulae and Arabic folk astronomy. As I mentioned before, al-Ṣūfī’s work was first translated into Persian by al-Ṭūsī. It was also translated into Spanish in the 13th century during the reign of King Alfonso X. The introductory chapter of al-Ṣūfī’s work was first translated into French by J.J.A. Caussin de Parceval in 1831. However in 1874 it was entirely translated into French again by Hans Karl Frederik Schjellerup, whose work became the main reference used by most modern astronomical historians. In 1956 al-Ṣūfī’s Book of the fixed stars was printed in its original Arabic language in Hyderabad (India) by Dārat al-Ma‘aref al-‘Uthmānīa. -
The Geography of Ptolemy Elucidated
The Grography of Ptolemy The geography of Ptolemy elucidated Thomas Glazebrook Rylands 1893 • A brief outline of the rise and progress of geographical inquiry prior to the time of Ptolemy. §1.—Introductory. IN tracing the early progress of Geography it is necessary to remember that, like all other sciences, it arose from “ small beginnings.” When men began to move from place to place they naturally desired to tell the tale of their wanderings, both for their own satisfaction and for the information of others. Such accounts have now perished, but their results remain in the earliest records extant ; hence, it is impossible to begin an investigation into the history of Geography at the true fountain-head, though it is in some instances possible to guess the nature of the source from the character of the resultant stream. A further difficulty lies in the question as to where the science of Geography begins. A Greek would probably have answered when some discoverer first invented a method for map- ping out the distance between certain places, which distance conversely could be ascertained directly from the map. In accordance with modern method, the science of Geography might be said to begin when the subject ceased to be dealt with mythically or dogmatically ; when facts were collected and reduced to laws, while these laws again, or their prior facts, were connected with other laws—in the case of Geography with those of Mathematics and Astro- nomy. Perhaps it would be better to follow the latter principle of division, and consequently the history of Geography may be divided into two main stages—“ Pre-Scientific” and Scientific Geography—though strictly speaking, the name of Geography should be applied to the latter alone. -
The Magic of the Atwood Sphere
The magic of the Atwood Sphere Exactly a century ago, on June Dr. Jean-Michel Faidit 5, 1913, a “celestial sphere demon- Astronomical Society of France stration” by Professor Wallace W. Montpellier, France Atwood thrilled the populace of [email protected] Chicago. This machine, built to ac- commodate a dozen spectators, took up a concept popular in the eigh- teenth century: that of turning stel- lariums. The impact was consider- able. It sparked the genesis of modern planetariums, leading 10 years lat- er to an invention by Bauersfeld, engineer of the Zeiss Company, the Deutsche Museum in Munich. Since ancient times, mankind has sought to represent the sky and the stars. Two trends emerged. First, stars and constellations were easy, especially drawn on maps or globes. This was the case, for example, in Egypt with the Zodiac of Dendera or in the Greco-Ro- man world with the statue of Atlas support- ing the sky, like that of the Farnese Atlas at the National Archaeological Museum of Na- ples. But things were more complicated when it came to include the sun, moon, planets, and their apparent motions. Ingenious mecha- nisms were developed early as the Antiky- thera mechanism, found at the bottom of the Aegean Sea in 1900 and currently an exhibi- tion until July at the Conservatoire National des Arts et Métiers in Paris. During two millennia, the human mind and ingenuity worked constantly develop- ing and combining these two approaches us- ing a variety of media: astrolabes, quadrants, armillary spheres, astronomical clocks, co- pernican orreries and celestial globes, cul- minating with the famous Coronelli globes offered to Louis XIV. -
Thinking Outside the Sphere Views of the Stars from Aristotle to Herschel Thinking Outside the Sphere
Thinking Outside the Sphere Views of the Stars from Aristotle to Herschel Thinking Outside the Sphere A Constellation of Rare Books from the History of Science Collection The exhibition was made possible by generous support from Mr. & Mrs. James B. Hebenstreit and Mrs. Lathrop M. Gates. CATALOG OF THE EXHIBITION Linda Hall Library Linda Hall Library of Science, Engineering and Technology Cynthia J. Rogers, Curator 5109 Cherry Street Kansas City MO 64110 1 Thinking Outside the Sphere is held in copyright by the Linda Hall Library, 2010, and any reproduction of text or images requires permission. The Linda Hall Library is an independently funded library devoted to science, engineering and technology which is used extensively by The exhibition opened at the Linda Hall Library April 22 and closed companies, academic institutions and individuals throughout the world. September 18, 2010. The Library was established by the wills of Herbert and Linda Hall and opened in 1946. It is located on a 14 acre arboretum in Kansas City, Missouri, the site of the former home of Herbert and Linda Hall. Sources of images on preliminary pages: Page 1, cover left: Peter Apian. Cosmographia, 1550. We invite you to visit the Library or our website at www.lindahlll.org. Page 1, right: Camille Flammarion. L'atmosphère météorologie populaire, 1888. Page 3, Table of contents: Leonhard Euler. Theoria motuum planetarum et cometarum, 1744. 2 Table of Contents Introduction Section1 The Ancient Universe Section2 The Enduring Earth-Centered System Section3 The Sun Takes