DOCSLIB.ORG

Scientificastronomerdocumentati

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Mathematica ® is a registered trademark of Wolfram Research, Inc. All other product names mentioned are trademarks of their producers. Mathematica is not associated with Mathematica Policy Research, Inc. or MathTech, Inc. March 1997 First edition, Intended for use with either Mathematica Version 3 or 4 Software and manual written by: Terry Robb Editor: Jan Progen Proofreader: Laurie Kaufmann Graphic design: Kimberly Michael Software Copyright 1997–1999 by Stellar Software. Published by Wolfram Research, Inc., Champaign, Illinois. All rights reserved. No part of this document may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechani - cal, photocopying, recording or otherwise, without the prior written permission of the author Terry Robb and Wolfram Research, Inc. Stellar Software is the holder of the copyright to the Scientific Astronomer package software and documentation (“Product”) described in this document, including without limitation such aspects of the Product as its code, structure, sequence, organization, “look and feel”, programming language and compilation of command names. Use of the Product, unless pursuant to the terms of a license granted by Wolfram Research, Inc. or as otherwise authorized by law, is an infringement of the copyright. The author Terry Robb, Stellar Software, and Wolfram Research, Inc. make no representations, express or implied, with respect to this Product, including without limitations, any implied warranties of merchantability or fitness for a particular purpose, all of which are expressly disclaimed. Users should be aware that included in the terms and conditions under which Wolfram Research, Inc. is willing to license the Product is a provision that the author Terry Robb, Stellar Software, Wolfram Research, Inc., and distribution licensees, distributors and dealers shall in no event by liable for any indirect, incidental or consequential damages, and that liability for direct damages shall be limited to the amount of the purchase price paid for the Product. In addition to the foregoing, users should recognize that all complex software systems and their documentation contain errors and omissions. The author Terry Robb, Stellar Software, and Wolfram Research, Inc. shall not be responsible under any circumstances for providing information on or corrections to errors and omissions discovered at any time in this document or the package software it describes, whether or not they are aware of the errors or omissions. The author Terry Robb, Stellar Software, and Wolfram Research, Inc. do not recommend the use of the software described in this document for applications in which errors or omissions could threaten life, injury, or significant loss. 10 9 8 7 6 5 4 3 #T2261 12/8/2000 Table of Contents Graphics Gallery v 1. Introduction 1 About the Package • Loading and Setup • Installation and Notebooks • Palettes and Buttons 2. Basic Functions 13 The Ephemeris and Appearance Functions • The PlanetChart and EclipticChart Functions • The Planisphere Function • The SunRise and NewMoon Functions • The BestView and InterestingObjects Functions 3. Coordinate Functions 35 The EquatorCoordinates Function • The HorizonCoordinates Function • The Coordinates Function • The JupiterCoordinates Function 4. Star Charting Functions 47 The StarChart Function • The RadialStarChart Function • The CompassStarChart Function • The ZenithStarChart Function • The StarNames Function • The OrbitTrack and OrbitMark Functions • The ChartCoordinates and ChartPosition Functions 5. Planet Plotting Functions 85 The PlanetPlot Function • The PlanetPlot3D Function • The RiseSetChart Function • The VenusChart Function • The OuterPlanetChart Function • The PtolemyChart Function • The SolarSystemPlot Function • The JupiterSystemPlot Function • The JupiterMoonChart Function 6. Eclipse Predicting Functions 119 The EclipseTrackPlot Function • The MoonShadow and SolarEclipse Functions • The EclipseBegin and EclipseEnd Functions • The EclipseQ Function • The Conjunction and ConjunctionEvents Functions 7. Satellite Tracking Functions 137 The SetOrbitalElements Function • The GetLocation Function • The OrbitTrackPlot Function • The OrbitPlot and OrbitPlot3D Functions 8. Miscellaneous Functions 153 The Separation and PositionAngle Functions • The FindNearestObject Function • The SiderealTime and HourAngle Functions • The Lunation and LunationNumber Functions • The NGC and IC Functions 9. Additional Information 167 Ephemeris Accuracy • Using PlanetChart • Using StarChart • Using RadialStarChart • Planetographic Coordinates Appendix. Special Events 175 Meteor Showers • Sunspots • Solar Eclipses • Lunar Eclipses • Transits of Mercury • Transits of Venus • Saturn’s Rings Edge On • Uranus’ Poles Side On • Mercury Apparitions • Venus Apparitions • Mars Opposition • Jupiter Opposition • Saturn Opposition • Lunar Occultations • Eclipse Table • Deep Sky Data • Brightest Stars • Double Stars • Variable Stars • Planetary Data • Visible Earth Satellites • Deep Sky Objects Index 199 Graphics Gallery v Main Features of Scientific Astronomer Feature Labeling on the Moon Star Charts: Five types of charts are defined in Scientific Astronomer, including two wide field star charts. With the star charts you can zoom into any portion of the sky. All the charts have options to show star spectral colors, mesh lines, a skyline, the horizon line, and the Milky Way; and to label constellations, stars, planets, deep sky objects, and so on. Mare Frigoris Planet Plots: Planet plotting is done in two- and three-dimensional forms. Surface features for the Earth, the Moon, Mars, and Jupiter are shown on the plots. Moons and their shadows are displayed for the Earth and Jupiter. Related functions allow you to produce planet position finder charts and planet Mare Imbrium Mare rise/set timing charts. Serenitatis Mare Eclipses: Several functions are provided for dealing with eclipses. These Crisium functions provide information about both solar and lunar eclipses, and are Oceanus Mare Mare general enough to handle Galilean moon eclipses, occultation of stars by the Procellarum Vaporum Tranquillitatis Moon, and transits of Mercury or Venus across the solar disk. You can Mare produce umbra and penumbra track plots and perform eclipse prediction. Foecunditatis Satellite Tracking: Satellite tracking is another feature of Scientific Mare Nectaris Astronomer. You can create track plots, make visibility predictions, and Mare project satellite tracks onto star charts. Nubium Mare Miscellaneous: Miscellaneous other features are available, such as producing Humorum planisphere plates, planet charts, and solar system plots. In addition, sunrise, moonrise, and full moon functions are provided, as well as functions for adding new objects, such as comets and satellites. Scientific Astronomer is Mathematica 3 and 4 compatible. It has palettes and buttons and is fully integrated into the Help Browser system. Plot of a full moon with features labeled. Terry Robb, March 1997. Star Chart of Ophiuchus Mercury Finder Chart Mercury Sector5 45 Summer Dec Nov Oct Lyra Spring Sep Aug 30 Hercules Jul Morning Evening Winter Jun May Sagitta Apr 15 Autumn Mar Feb Aquila Jan 2am 4am 6am 8am 10am 1994 2pm 4pm 6pm 8pm 10pm 0 Ophiuchus Chart showing rising and setting times of Mercury during 1994 for an observer 35 degrees Serpens south of the equator. Green areas (or the darker shade of gray) show when Mercury is visible above the horizon. Scutum -15 HaleBopp Winter Dec Nov Sagittarius Morning Evening Oct Autumn Sep -30 Scorpius Aug Jul Summer Jun CoronaAustralis May -45 19h 18h 17h 16h Apr Spring Mar Morning Evening Star chart showing various constellations in the direction of Ophiuchus. Scorpius is Feb visible on the bottom right. The blue line near the bottom is the ecliptic, which is the fixed Jan path of the Sun through the sky. The planets and Moon all roughly move along that line as 2am 4am 6am 8am 10am 1997 2pm 4pm 6pm 8pm 10pm well. Chart showing rising and setting times of Comet Hale-Bopp during 1997 for an observer 40 degrees north of the equator. Green areas show when Hale-Bopp is visible. vi Graphics Gallery Milky Way and Nebulae Jupiter's Moons and Great Red Spot 5 K=12 Impact 0 Ophiuchus {1994, 7, 19, 20, 15, 0} 5 Serpens 10 Scutum 15 NGC: 6611 NGC: 6618 20 Sagittarius NGC: 6514 25 NGC: 6523 Antares 30 Scorpius 35 40 CoronaAustralis 45 19h 18h 17h 16h Star chart showing the Milky Way in the region of Scorpius and Sagittarius. Four Fragment of Comet P/Shoemaker-Levy impacting on Jupiter. Two Jovian moons and the binocular-visible nebulae are indicated by the position of the yellow NGC numbers. Star Great Red Spot are visible. This graphic is part of a large animation. spectral colors of stars, such as red for Antares, are also indicated. Eight-Year Venus Finder Chart Retrograde Motion of Mars 40 D 35 N D O S O N A N 30 Evening A J S Morning D S J J J M M A A O D O J M J 25 A M F A Gemini F A M J M J N F J M S J M 1999 1994 J N 20 Taurus S 1997 F A A J J Cancer J 1996 A D F 2000 J 15 M O M Sun M O M 2001 J F J D A 1995 J J A 10 A F S 1998 J N J M CanisMinor N S M F 5 J M M A A Orion J J O 0 Monoceros D O A S D -5 N Venus Evening Morning -10 Earth -15 -20 Finder chart for Venus for years 1994 through 2001. 8h 6h 4h Star chart track of Mars undergoing retrograde motion during 1992. Graphics Gallery vii Plot of Earth Optional Labeling 20 15 Aldebaran 10 α γ π3 5 Betelgeuse δ 0 ζε η ι 5 β κ 10 Rigel 15 6h 5h Plot of Earth as viewed from directly over Melbourne, Australia. The darker area Star chart of constellation Orion using double-size labeling. represents night, which is the half of the globe not illuminated by the Sun. Overhead Sky Lunar Eclipse Chart NorthNorth Latitude Nov 17 38 South 03:20 Partial Partial Total Total 22:10 01:47 00:46 Moon 23:11 Begin East West End End Begin Umbra East West Penumbra Partial for 217 min. Total for 96 min.
Recommended publications
  • Exploring the Origin of Magnetic Fields in Massive Stars: II. New Magnetic

    Exploring the Origin of Magnetic Fields in Massive Stars: II. New Magnetic

    Astronomy & Astrophysics manuscript no. ostars˙2011˙sw c ESO 2018 March 8, 2018 Exploring the origin of magnetic fields in massive stars: II. New magnetic field measurements in cluster and field stars.⋆ S. Hubrig1, M. Sch¨oller2, I. Ilyin1, N. V. Kharchenko3, L. M. Oskinova4, N. Langer5, J. F. Gonz´alez6, A. F. Kholtygin7, M. Briquet8⋆⋆, and the MAGORI collaboration 1 Leibniz-Institut f¨ur Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany 2 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany 3 Main Astronomical Observatory, 27 Academica Zabolotnogo Str., 03680 Kiev, Ukraine 4 Universit¨at Potsdam, Institut f¨ur Physik und Astronomie, 14476 Potsdam, Germany 5 Argelander-Institut f¨ur Astronomie, Universit¨at Bonn, Auf dem H¨ugel 71, 53121 Bonn, Germany 6 Instituto de Ciencias Astronomicas, de la Tierra, y del Espacio (ICATE), 5400 San Juan, Argentina 7 Astronomical Institute, Saint-Petersburg State University, Saint-Petersburg, Russia 8 Institut d’Astrophysique et de G´eophysique, Universit´e de Li`ege, All´ee du 6 Aoˆut 17, 4000 Li`ege, Belgium Received date / Accepted date ABSTRACT Context. Theories on the origin of magnetic fields in massive stars remain poorly developed, because the properties of their magnetic field as function of stellar parameters could not yet be investigated. Additional observations are of utmost importance to constrain the conditions that are conducive to magnetic fields and to determine first trends about their occurrence rate and field strength distribution. Aims. To investigate whether magnetic fields in massive stars are ubiquitous or appear only in stars with a specific spectral classification, certain ages, or in a special environment, we acquired 67 new spectropolarimetric observations for 30 massive stars.
  • Naming the Extrasolar Planets

    Naming the Extrasolar Planets

    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
  • 12.3 the Moon: Phases, Eclipses, and the Tides

    12.3 the Moon: Phases, Eclipses, and the Tides

    12.3 The Moon: Phases, Eclipses, and the Tides 1. The Motions of the Moon a. Rotation i. Period of Moon’s rotation = 27.3 days b. Revolution (orbit) i. Period of the Moon’s orbit around the Earth = 27.3 days ii. Lunar cycle = 29.5 days (time that the calendar month is based on) 1. Time needed for the moon to return to the same place in the sky 2. Since the Earth is orbiting as well as the Moon, the Moon needs the extra 2 days to “catch up to the Earth” in its orbit c. Orbital period of the moon = the rotational period of the moon = 27.3 days i. Synchronous rotation ii. Reason that we only see one side of the Moon 2. Phases of the Moon a. Order of the phases i. Based on the Moon appears to us on Earth ii. New moon, waxing crescent, 1st quarter, waxing gibbous, full moon, waning gibbous, 3rd/last quarter, waning crescent b. The sun’s light moves from right to left across the face of the moon c. Moonrise and moonset i. Time when one’s location on Earth can see the moon 3. Eclipses a. Any time one celestial body passes between another celestial body and the Sun b. Lunar eclipse i. Partial lunar eclipse; when the any part of the Moon falls within the penumbra (partial shadow) of the Earth ii. Total lunar eclipse; when the Moon falls entirely within the umbra (total shadow) of the Earth c. Solar eclipse i. Partial solar eclipse; when any point on the Earth falls within the penumbra (partial shadow) of the Moon ii.
  • N O T I C E This Document Has Been Reproduced From

    N O T I C E This Document Has Been Reproduced From

    N O T I C E THIS DOCUMENT HAS BEEN REPRODUCED FROM MICROFICHE. ALTHOUGH IT IS RECOGNIZED THAT CERTAIN PORTIONS ARE ILLEGIBLE, IT IS BEING RELEASED IN THE INTEREST OF MAKING AVAILABLE AS MUCH INFORMATION AS POSSIBLE P993-198422 International Collogium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas (4th) Held at the National institute of Standards and Technology Gaithersburg, Maryland on September 14-17, 1992 (U.S.) National inst. of Standards and Technology (PL) Gaithersburg, MD Apr 93 US. DEPARTMENT OF COMMERCE Ndioul Techcical IMermeNON Service B•11G 2-10i1A2 2 MIST-1 /4 U.S. VZPARTMENT OF COMMERCE (REV. NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY M GONTSOLw1N^BENN O4" COMM 4M /. MANUSCRIPT REVIEW AND APPROVAL "KIST/ p-850 ^' THIS NSTRUCTWNS: ATTACH ORIGINAL OF FORM TO ONE (1) COPY OF MANUSCIIN IT AND SEINE TO: PUBLICATIOM OATS NUMBER PRINTED PAGES April 1993 199 HE SECRETAIIY, APPROPRIATE EDITO RIAL REVIEW BOARD. ITLE AND SUBTITLE (CITE NN PULL) 4rh International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas -- POSTER PAPERS :ONTIEACT OR GRANT NUMBER TYPE OF REPORT AND/OR PERIOD COMM UTHOR(S) (LAST %,TAME, POST NNITIAL, SECOND INITIAL) PERFORM" ORGANIZATION (CHECK (IQ ONE SOX) EDITORS XXX MIST/GAITHERSBUIIG Sugar, Jack and Leckrone, B:;vid INST/BODUM JILA BOIRDE11 "ORATORY AND DIVISION NAMES (FIRST MOST AUTHOR ONLY) Physics Laboratory/Atomic Physics Division 'PONSORING ORGANIZATION NAME AND COMPLETE ADDRESS TREET, CITY. STATE. ZNh ^y((S/ ,T AiL7A - -ASO IECOMMENDsO FOR MIST PUBLICATION JOVIAMAL OF RESEMICM (MIST JRES) CIONOGRAPK (MIST MN) LETTER CIRCULAR J. PHYS. A CHEM.
  • Chapter 19 the Almanacs

    Chapter 19 the Almanacs

    CHAPTER 19 THE ALMANACS PURPOSE OF ALMANACS 1900. Introduction The Air Almanac was originally intended for air navigators, but is used today mostly by a segment of the Celestial navigation requires accurate predictions of the maritime community. In general, the information is similar to geographic positions of the celestial bodies observed. These the Nautical Almanac, but is given to a precision of 1' of arc predictions are available from three almanacs published and 1 second of time, at intervals of 10 minutes (values for annually by the United States Naval Observatory and H. M. the Sun and Aries are given to a precision of 0.1'). This Nautical Almanac Office, Royal Greenwich Observatory. publication is suitable for ordinary navigation at sea, but The Astronomical Almanac precisely tabulates celestial lacks the precision of the Nautical Almanac, and provides data for the exacting requirements found in several scientific GHA and declination for only the 57 commonly used fields. Its precision is far greater than that required by navigation stars. celestial navigation. Even if the Astronomical Almanac is The Multi-Year Interactive Computer Almanac used for celestial navigation, it will not necessarily result in (MICA) is a computerized almanac produced by the U.S. more accurate fixes due to the limitations of other aspects of Naval Observatory. This and other web-based calculators are the celestial navigation process. available from: http://aa.usno.navy.mil. The Navy’s The Nautical Almanac contains the astronomical STELLA program, found aboard all seagoing naval vessels, information specifically needed by marine navigators. contains an interactive almanac as well.
  • Naked-Eye Observations of the Moon (See Also Take-Home Exp

    Naked-Eye Observations of the Moon (See Also Take-Home Exp

    TAKE-HOME EXP. # 3 Naked-Eye Observations of the Moon (See also Take-Home Exp. #4 which can easily be done at the same time as this one.) You have already seen what the Moon looks like in its various phases, but you may not realize it can be "out" in the day as well as the night. Nor are most people familiar enough with the geometry of the Sun-Moon-Earth system to draw it as easily as you will be able to by the end of this experiment. a. When to make observations of the moon's phases: nytime you can find the Moon, make an observation. These observations do not have to occur only at the principal phases. Anytime and anywhere you can see the Moon is a good time to make a sketch and record the requested information. b. Dates of the Principal phases of the Moon, Times of Moonrise, and Moonset: Earth When doing this experiment, check your newspaper New Moon everyday for the times of moonrise and moonset; they are listed on the weather page. Many calendars show the days of occurrence of the principal phases--new, first- 1st Qrtr quarter, full, third quarter--of the Moon. Most newspapers have the principal phase dates listed every day. In the view of Earth pictured to the right, the Moon’s orbit is the circle, and incoming sunlight is from the right. Full The Moon moves counterclockwise around the Earth, taking 28 days to complete its cycle. Starting at the topmost diagram, a “New Moon” phase, seven days elapse between each succeeding diagram.
  • Educator's Guide: Orion

    Educator's Guide: Orion

    Legends of the Night Sky Orion Educator’s Guide Grades K - 8 Written By: Dr. Phil Wymer, Ph.D. & Art Klinger Legends of the Night Sky: Orion Educator’s Guide Table of Contents Introduction………………………………………………………………....3 Constellations; General Overview……………………………………..4 Orion…………………………………………………………………………..22 Scorpius……………………………………………………………………….36 Canis Major…………………………………………………………………..45 Canis Minor…………………………………………………………………..52 Lesson Plans………………………………………………………………….56 Coloring Book…………………………………………………………………….….57 Hand Angles……………………………………………………………………….…64 Constellation Research..…………………………………………………….……71 When and Where to View Orion…………………………………….……..…77 Angles For Locating Orion..…………………………………………...……….78 Overhead Projector Punch Out of Orion……………………………………82 Where on Earth is: Thrace, Lemnos, and Crete?.............................83 Appendix………………………………………………………………………86 Copyright©2003, Audio Visual Imagineering, Inc. 2 Legends of the Night Sky: Orion Educator’s Guide Introduction It is our belief that “Legends of the Night sky: Orion” is the best multi-grade (K – 8), multi-disciplinary education package on the market today. It consists of a humorous 24-minute show and educator’s package. The Orion Educator’s Guide is designed for Planetarians, Teachers, and parents. The information is researched, organized, and laid out so that the educator need not spend hours coming up with lesson plans or labs. This has already been accomplished by certified educators. The guide is written to alleviate the fear of space and the night sky (that many elementary and middle school teachers have) when it comes to that section of the science lesson plan. It is an excellent tool that allows the parents to be a part of the learning experience. The guide is devised in such a way that there are plenty of visuals to assist the educator and student in finding the Winter constellations.
  • A Basic Requirement for Studying the Heavens Is Determining Where In

    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).
  • La Photosynthèse Serait Apparue Chez Certains Organismes Primitifs Entre 2.800 Et -2.400 Millions D’Années Si L’On En Croit Certaines Archives Géologiques Terrestres

    La Photosynthèse Serait Apparue Chez Certains Organismes Primitifs Entre 2.800 Et -2.400 Millions D’Années Si L’On En Croit Certaines Archives Géologiques Terrestres

    La photosynthèse serait apparue chez certains organismes primitifs entre 2.800 et -2.400 millions d’années si l’on en croit certaines archives géologiques terrestres. Mais certains la font remonter bien plus tôt en faisant l’hypothèse que les stromatolites que l’on retrouve dans des couches plus anciennes encore sont bien le produit d’une activité biologique. Actuellement, nous n’en sommes sûrs que pour ceux datant de -2.724 millions d’années mais des stromatolites existaient déjà sur Terre il y a 3,5 milliards d’années environ. Quoiqu'il en soit, une certitude demeure, concernant les immenses dépôts de fer du bassin de Hamersley en Australie. Ils datent de l’époque du Sidérien alors que la surface des continents était devenue suffisamment importante pour que se forment des mers peu profondes entourées de grande plates-formes continentales. Les conditions étaient remplies pour que de grands tapis de bactéries construisent des stromatolites en quantités importantes et dégagent massivement de l’oxygène par photosynthèse. Ce gaz corrosif a alors pu oxyder le fer en solution dans les océans et entraîner sa précipitation sous forme d’hydroxyde de fer, de carbonate de fer, de silicate ou de sulfures, selon des variations de l’acidité et du degré d’oxydoréduction de l’eau de mer. C’est ce qu’on appelle la Grande oxydation ou la Catastrophe de l’oxygène. Vers -1.900 millions d’années, la presque totalité du fer présent dans les océans avait précipité et il se retrouve aujourd’hui dans les grands gisements de minerai mondiaux tels que ceux de Hamersley.
  • September 2020 BRAS Newsletter

    September 2020 BRAS Newsletter

    A Neowise Comet 2020, photo by Ralf Rohner of Skypointer Photography Monthly Meeting September 14th at 7:00 PM, via Jitsi (Monthly meetings are on 2nd Mondays at Highland Road Park Observatory, temporarily during quarantine at meet.jit.si/BRASMeets). GUEST SPEAKER: NASA Michoud Assembly Facility Director, Robert Champion What's In This Issue? President’s Message Secretary's Summary Business Meeting Minutes Outreach Report Asteroid and Comet News Light Pollution Committee Report Globe at Night Member’s Corner –My Quest For A Dark Place, by Chris Carlton Astro-Photos by BRAS Members Messages from the HRPO REMOTE DISCUSSION Solar Viewing Plus Night Mercurian Elongation Spooky Sensation Great Martian Opposition Observing Notes: Aquila – The Eagle Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 27 September 2020 President’s Message Welcome to September. You may have noticed that this newsletter is showing up a little bit later than usual, and it’s for good reason: release of the newsletter will now happen after the monthly business meeting so that we can have a chance to keep everybody up to date on the latest information. Sometimes, this will mean the newsletter shows up a couple of days late. But, the upshot is that you’ll now be able to see what we discussed at the recent business meeting and have time to digest it before our general meeting in case you want to give some feedback. Now that we’re on the new format, business meetings (and the oft neglected Light Pollution Committee Meeting), are going to start being open to all members of the club again by simply joining up in the respective chat rooms the Wednesday before the first Monday of the month—which I encourage people to do, especially if you have some ideas you want to see the club put into action.
  • FIXED STARS a SOLAR WRITER REPORT for Churchill Winston WRITTEN by DIANA K ROSENBERG Page 2

    FIXED STARS a SOLAR WRITER REPORT for Churchill Winston WRITTEN by DIANA K ROSENBERG Page 2

    FIXED STARS A SOLAR WRITER REPORT for Churchill Winston WRITTEN BY DIANA K ROSENBERG Page 2 Prepared by Cafe Astrology cafeastrology.com Page 23 Churchill Winston Natal Chart Nov 30 1874 1:30 am GMT +0:00 Blenhein Castle 51°N48' 001°W22' 29°‚ 53' Tropical ƒ Placidus 02' 23° „ Ý 06° 46' Á ¿ 21° 15° Ý 06' „ 25' 23° 13' Œ À ¶29° Œ 28° … „ Ü É Ü 06° 36' 26' 25° 43' Œ 51'Ü áá Œ 29° ’ 29° “ àà … ‘ à ‹ – 55' á á 55' á †32' 16° 34' ¼ † 23° 51'Œ 23° ½ † 06' 25° “ ’ † Ê ’ ‹ 43' 35' 35' 06° ‡ Š 17° 43' Œ 09° º ˆ 01' 01' 07° ˆ ‰ ¾ 23° 22° 08° 02' ‡ ¸ Š 46' » Ï 06° 29°ˆ 53' ‰ Page 234 Astrological Summary Chart Point Positions: Churchill Winston Planet Sign Position House Comment The Moon Leo 29°Le36' 11th The Sun Sagittarius 7°Sg43' 3rd Mercury Scorpio 17°Sc35' 2nd Venus Sagittarius 22°Sg01' 3rd Mars Libra 16°Li32' 1st Jupiter Libra 23°Li34' 1st Saturn Aquarius 9°Aq35' 5th Uranus Leo 15°Le13' 11th Neptune Aries 28°Ar26' 8th Pluto Taurus 21°Ta25' 8th The North Node Aries 25°Ar51' 8th The South Node Libra 25°Li51' 2nd The Ascendant Virgo 29°Vi55' 1st The Midheaven Gemini 29°Ge53' 10th The Part of Fortune Capricorn 8°Cp01' 4th Chart Point Aspects Planet Aspect Planet Orb App/Sep The Moon Semisquare Mars 1°56' Applying The Moon Trine Neptune 1°10' Separating The Moon Trine The North Node 3°45' Separating The Moon Sextile The Midheaven 0°17' Applying The Sun Semisquare Jupiter 0°50' Applying The Sun Sextile Saturn 1°52' Applying The Sun Trine Uranus 7°30' Applying Mercury Square Uranus 2°21' Separating Mercury Opposition Pluto 3°49' Applying Venus Sextile
  • The Kappa Andromedae System: New Constraints on the Companion

    The Kappa Andromedae System: New Constraints on the Companion

    Draft version June 25, 2018 A Preprint typeset using LTEX style emulateapj v. 5/2/11 THE κ ANDROMEDAE SYSTEM: NEW CONSTRAINTS ON THE COMPANION MASS, SYSTEM AGE & FURTHER MULTIPLICITY Sasha Hinkley1,17, Laurent Pueyo2,18, Jacqueline K. Faherty3, Ben R. Oppenheimer4, Eric E. Mamajek5, Adam L. Kraus6, Emily Rice7,3, Michael J. Ireland 8,9, Trevor David1, Lynne A. Hillenbrand1, Gautam Vasisht10, Eric Cady10, Douglas Brenner4, Aaron Veicht4, Ricky Nilsson4, Neil Zimmerman11, Ian R. Parry12, Charles Beichman13, Richard Dekany14, Jennifer E. Roberts10, Lewis C Roberts Jr.10, Christoph Baranec14, Justin R. Crepp15, Rick Burruss10, J. Kent Wallace10, David King12, Chengxing Zhai10, Thomas Lockhart10, Michael Shao10, Remi´ Soummer2, Anand Sivaramakrishnan2, Louis A. Wilson16 Draft version June 25, 2018 ABSTRACT κ Andromedae is a B9IVn star at 52 pc for which a faint substellar companion separated by 55±2 AU was recently announced. In this work, we present the first spectrum of the companion, “κ And B,” using the Project 1640 high-contrast imaging platform. Comparison of our low-resolution YJH-band spectra to empirical brown dwarf spectra suggests an early-L spectral type. Fitting synthetic spectra from PHOENIX model atmospheres to our observed spectrum allows us to constrain the effective temperature to ∼2000 K, as well as place constraints on the companion surface gravity. Further, we use previously reported log(g) and Teff measurements of the host star to argue that the κ And system has an isochronal age of 220±100 Myr, older than the 30 Myr age reported previously. This interpretation of an older age is corroborated by the photometric properties of κ And B, which appear to be marginally inconsistent with other 10-100 Myr low-gravity L-dwarfs for the spectral type range we derive.