A Publication of the International Dark-Sky Association

Total Page:16

File Type:pdf, Size:1020Kb

A Publication of the International Dark-Sky Association ISSUE # 75 • SPECIAL 20 PAGE ISSUE • $2.50 nightscape A PUBLICATION OF THE INTERNATIONAL DARK-SKY ASSOCIATION Photograph by Laurent Laveder Laurent by Photograph IN THIS ISSUE Meeting News 4–6 Lighting News 7 IYA 2009 Feature Article 8 –13 Book Review 14 Section News 16 & 17 Transitions 18 SCG_K901 Dark Sky_111708:Layout 1 11/17/08 2:18 PM Page 1 K901 CENTURION TM LUMINAIRE FROM KING LUMINAIRE DARK SKY FRIENDLY ™ King Luminaire presents the K901 Centurion™ Decorative Area Luminaire, designed for use in both street and parking lot lighting applications. Its contemporary design, combined with King’s commitment to superior photometric performance, ease of maintenance, and design integrity, makes it a leading choice among engineers, architects, and specifiers alike. ■ High Photometric Performance ■ Extremely Well Engineered ■ Dark-Sky Friendly™, Full Cutoff Fixture SUPERIOR PERFORMANCE ■ 4 Different Mounting Options ■ Completely tool-less entry Be sure to visit our company website to view our new line of LED Post Top Fixitures at www.StressCreteGroup.com Northport, Alabama ■ Jefferson, Ohio ■ Atchison, Kansas ■ Burlington, Ontario Dear Members, InternationalID Dark-ASky Association The mission of the International Dark-Sky Association 2008 has been a landmark year for the International Dark-Sky Association! (IDA) is to preserve and protect the nighttime environment and our heritage of dark skies. IDA was incorporated in he vision of Dr. David Crawford and Dr. Tim Hunter, founders of IDA 20 years 1988 as a tax-exempt 501(c)(3) nonprofit organization Tago, is reaching critical mass with advances worldwide in the pursuit of dark sky (FIN 74-2493011). awareness and the sensitivity of various lighting applications in the nightscape. SECTIONS & AFFILIATES The highlights of 2008 extend far and wide: High visibility articles and features in the National Geographic magazine, Sections Argentina, Australia, Canada (3), Chile, Česká Republika/Czech Republic, China, Éire/Ireland, the New York Times and The Wall Street Journal outlined the environmental, Israel, Ελλάςα/Greece, 香港/Hong Kong, Italia/Italy, health, and human heritage implications of less-than-ideal applications of outdoor 日本/Japan, Malta, Österreich/Austria, Slovenija/ lighting systems. Slovenia, Schweiz/Switzerland, Sverige/Sweden, The IDA Asia-Pacific office continues to make inroads into China, Southeast United States (34) Asia, India and the Middle East. Director Reg Wilson is also part of the committee Affiliates België/Belgium, Deutschland/Germany, France, Nederland/Netherlands, Polska/Poland, United that is in the process of updating the Australian National Outdoor Lighting Kingdom, United States (8) Standard that will build upon past successes “Down Under.” The 20th Anniversary IDA Annual Meeting saw the presentation of the BOARD OF DIRECTORS Inaugural David L. Crawford Lifetime Achievement Award to Jack Sales to com- President Christian Monrad P.E. memorate all that Dr. Crawford and Jack Sales have done for the organization. Vice President Buell Jannuzi European IDA members and affiliates extended their influence in numerous Secretary Daniel Brocious jurisdictions and Freidel Pas, IDA’s European Office Director, was awarded the Treasurer James Benya 2008 IDA Hoag-Robinson Award. Dr. Chris Baddiley’s watershed study on sky Members Kelly Beatty; Nancy Clanton; Paul Ericson; glow was published and also presented at the 2008 IDA Annual Meeting as well Audrey Fischer; Terry McGowan; Martin Morgan-Taylor; Leo Smith; Friedel Pas; Wout van Bommel; Robert as the very successful 2008 European Symposium for the Protection of the Night Wagner; Christopher Walker; Reginald Wilson Sky, where Dr. Baddiley earned the Galileo Award from IDA Europe. The International Dark Sky Places program awarded new certifications to Cherry Springs State Park in Pennsylvania and Geauga Park District Observatory STAFF Park in Ohio on the heels of the 2007 certification of the Mont Mégantic Managing Director Peter Strasser Programs Director Kimberly Patten International Dark Sky Reserve near Quebec, Canada. Interest in similar Membership Director Susan Ciarniello certifications is being promoted in France, the UK and elsewhere. Writer/Editor Rowena Davis This summer, IDA staff and board members made presentations relative to Sections Coordinator Johanna Duffek IDA’s mission to elected officials and staff of the U.S. Congress and Senate. The Art and Design Stephanie Mar Technical Associate Matthew Root establishment of an IDA office in Washington, DC is currently being evaluated to strengthen IDA’s voice at the U.S. federal level. NEWSLETTER All of these successes are the result of many years of dedicated work by IDA Address corrections [email protected] volunteer members and like-minded individuals worldwide, IDA staff, Industry Advertisements & submissions [email protected] Partners, Emeritus Dr. David Crawford and his wife, longtime board secretary/ Deadlines Issue #76: 23 Feb. 2009; Issue #77: 23 May 2009; Issue # 78: 23 Aug. 2009; Issue # 79: 23 Nov. 2009 treasurer Mary Crawford. Nightscape, a publication of the International Dark-Sky On behalf of the board of directors, I thank you all and applaud the Association is published quarterly. outstanding progress that you have helped IDA secure and look forward to continued advancement in our mission around the world. CONTACT Address International Dark-Sky Association, Regards, 3225 N. First Ave., Tucson, AZ 85719-2103, U.S.A. Tel +1 520-293-3198 Fax + 1 520-293-3192 Web site www.darksky.org E-mail [email protected] AdVERTISING RATES Christian K. Monrad, P.E. President of the Board 1X Rate 4X Rate Inside Front Cover $960 $3600 To help IDA to continue in its worldwide mission, IDA needs your continued member- Inside Back Cover $960 $3600 ship and donations to fund its paid staff and the European and Asia-Pacific offices. Full page $800 $3000 Please refer to the IDA Web site for convenient renewal and donation methods. Half page $425 $1500 Quarter page $250 $850 A note from IDA: Is your mailing address and e-mail up to date? If not, For more information contact please update your information at IDA’s Web site at www.darksky.org. [email protected] Issue #75/ 2008 3 DarkSky 2008 By Friedel Pas Photograph by Peter Wienerroither Peter by Photograph he European Symposium for the Protection of the Night Sky Tis a yearly event where dark sky advocates, environmentalists, scientists, lighting designers and representatives from governments in Europe meet each other on the theme of light pollution. It is a collaboration between IDA Europe and a local IDA Section. This year the organization was in the hands of IDA Austria, and the meeting was held in the beautiful Kuffner-Verein observatory in Vienna from 22 to 23 of August. A starry night at Hohe Wand, south of Vienna, Austria The meeting was opened by honoring Dr. Chris efficiency of legislation on light pollution. Day one featured Baddiley with the Galileo Award. This award is presented a fascinating lecture by Itai Kloog, where he explained yearly to a European IDA member who did outstanding his study showing a correlation between the number of work toward the control of light pollution in Europe. installed public lighting fixtures and the appearance of Dr. Baddiley is recognized for his research of more than breast cancer in Israel. Christoph Aubrecht spoke on the 3 years in modeling sky glow. His model illustrates the quality of coral reefs in the world measured against satellite effects of different types of luminaries and lamps in rural observations of light pollution. and urban environments as well enabling calculation of Current awareness campaigns in Europe were also escaped light from both long and short distances from a discussed. Austria led a big campaign to involve the govern- lighting fixture. The model is publicized by the Institution ment with a booklet and to motivate schools to participate of Lighting Engineers (ILE) in a booklet and included in in the campaign. The UK has initiated several activities to ILE educational courses for lighting designers. The work is facilitate the way that lighting regulations can be adopted used in light pollution research in the UK and is gaining in planning guidelines and building regulations. In France, acceptance around the world. IDA and IESNA adopted officials have worked out an acceptance test municipalities calculations from this model as a basis for the much-antici- could use to determine the best lighting systems. Germany pated Model Lighting Ordinance. Everybody agreed that circulated a petition that resulted in a discussion in the Dr. Baddiley’s work was very important and outstanding. Bundestag, the parliament in Germany. One person described it’s significance by stating: “All dark The symposium also featured a progress update on sky movements need members who can appeal to the Dr. Baddiley’s sky glow model and a review of the working emotions and principles of the public in order to convince document under construction by the EU to regulate out- them that action is necessary; but without a solid technical door lighting systems and promote more efficient products. basis and real ‘know-how’, our emotional arguments are Sponsor Schréder gave his view on light pollution and the poorer.” Chris Baddiley’s impeccable research helps the city planner of Vienna showed the city’s latest new create this technical basis. lighting choices with fully shielded fixtures. Some of these The symposium had a lot of interesting lectures by fixtures were installed around
Recommended publications
  • Nature Detectives
    Winter 2015 Star Light, Star Bright, Let’s Find Some Stars Tonight! Finding specific stars in the night sky might seem overwhelming. All those stars! At a glance stars look like a million twinkling points of light that are impossible to sort out. But with a little information, you may discover hunting some stars is not so difficult. Turns out we don’t see a million stars. Less than a couple thousand – and usually many fewer than that – are visible to most people’s unaided eyes. The brightest and nearest stars are easily found without a telescope or binoculars. Stars Are Not Star-shaped Stars are big balls of gas that give off heat and light. Sound familiar? Isn’t that what our Sun does? Guess what, our Sun is a star. It seems confusing, but all stars are suns. Like our Sun, stars are also in the daytime sky. During the day, the Sun lights up the atmosphere so we can’t see other suns… er…stars. Pull Out and Save Our Sun isn’t even the brightest star. In fact all the stars we see at night are bigger and brighter than the Sun. It wins the brightness contest during the day simply because it is incredibly closer than all the other stars. (At night we don’t see the Sun because of Earth’s rotation. Our Sun is shining on the opposite side of Earth and we are in darkness.) Suns or Stars Appear to Rise and Set Our view of the stars changes through the night as Earth makes its daily rotation.
    [Show full text]
  • Lecture Notes
    1/17/2020 Topics in Observational astrophysics Ian Parry, Lent 2020 Lecture 1 • Electromagnetic radiation from the sky. • What is a telescope? What is an instrument? • Effects of the Earth’s atmosphere: transparency, seeing, refraction, dispersion, background light. • Basic definition of magnitudes. • Imperfections in imaging systems. Lecture notes • www.ast.cam.ac.uk/~irp/teaching • Username: topics • Password: dotzenblobs • Email me ([email protected]) so that I can put you on my course email list. 1 1/17/2020 Introduction • Observational astronomy is mostly about measuring electromagnetic radiation HERE (on Earth and nearby) and NOW. Astronomy is an evidence based science. • We measure the intensity, arrival direction, wavelength, arrival time and polarisation state. • Astronomical sources are so far away that the parts of the spherical wavefronts that are ultimately collected by the telescope aperture are essentially flat just before they enter the Earth’s atmosphere. • A telescope is a device that collects pieces of incoming wavefronts and focuses them, i.e. turns them into converging spherical wavefronts. • An instrument is a device that comes after the telescope. It receives the wavefronts and further processes them by either optically manipulating them or converting the energy into measurable signals, or both. Telescope Instrument Primary Optional Optional Detector optics and telescope instrument initial pupil optics optics 2 1/17/2020 Examples • The human eye can be thought of as a telescope (pupil + lens) and an instrument (retina). • Similarly the camera in a phone or a laptop can be thought of as a telescope (pupil + lens) and an instrument (cmos detector). • The lens of an SLR camera is the telescope and the camera body is the instrument.
    [Show full text]
  • Fireworks from Outer Space, a Gift from Betelgeuse Understanding the Life of an Iconic Star from Astronomers’ Recent Observations
    Astronomy Fireworks from Outer Space, A Gift from Betelgeuse Understanding the Life of an Iconic Star From Astronomers’ Recent Observations Written by Sabrina Helck Illustrated by Mahamad Salah ave you ever looked up on a clear night and been fuses to carbon, carbon fuses to neon, and then neon to silicon. curious about the thousands of stars twinkling in the Finally, silicon fuses to iron. Once iron begins to form in that final sky? Well, maybe you do not think about it too much, step, the star's days are numbered. As fusion occurs, the center of H but all of those stars go through life cycles, and they are the star gets denser and denser. At this point, gravity takes over, each at different stages in their life. Sadly, an iconic star named and the star collapses in on itself. When this happens, it sets off an Betelgeuse seems to near the end of its life after astronomers explosion known as a supernova, and it looks spectacular. noticed it dimming. With the death of Betelgeuse comes an incredible celestial First, let us get to know Betelgeuse. Betelgeuse, performance, which is why the recent observations of Betelgeuse pronounced like the 1988 film, Beetlejuice, is the tenth brightest dimming are so exciting. It raises the possibility that the star may star in our night sky. It sits on the top left shoulder of the winter die soon and result in a supernova! Other astronomers speculate constellation, Orion. Although we can see Betelgeuse shining that the reason for its dimming was just a giant dust cloud, but let brightly in the sky, it is actually 642.5 light-years away, so about 385 us stick to the more exciting hypothesis.
    [Show full text]
  • ASTR 101 the Earth and the Sky August 29, 2018
    ASTR 101 The Earth and the Sky August 29, 2018 • Sky and the atmosphere • Twinkling of stars • The celestial sphere • Constellations • Star brightness and the magnitude system • Naming of stars Scattering of light and color of the sky Sun light more less scattering scattering air particle • During the daytime we cannot see stars due to the glare in the atmosphere (from sunlight). • When sunlight travels through the Earth’s atmosphere some of the light is scattered (deflected) off air molecules. • White light is a combination of different colors, blue light is scattered far more than red light. Blue Sky during the day Sun Earth atmosphere • During the day we see this scattered sunlight in the atmosphere. • Since most of it is blue, a lot of blue light is seen in the atmosphere in all directions, which makes the sky look blue. • Light from stars are fainter than scattered sunlight in the atmosphere, so we cannot see them (unless a star happen to be very bright) In the outer space sky is always dark • Away from the atmosphere (in outer space, on moon…) sky is always dark. • It is possible to see stars and the sun at the same time. The Sun looks red at Sunrise/Sunset Sun atmosphere Earth • At sunrise and sunset, Sun is close to the horizon. Sunlight has to travel a longer distance in the atmosphere to reach us. • By the time sunlight reaches ground most of the blue light has scattered off. Only red light remains. • So the Sun (moon…) looks red at sunrise or sunset.
    [Show full text]
  • Stellar Masses
    GENERAL I ARTICLE Stellar Masses B S Shylaja Introduction B S Shylaja is with the Bangalore Association for The twinkling diamonds in the night sky make us wonder at Science Education, which administers the their variety - while some are bright, some are faint; some are Jawaharlal Nehru blue and red. The attempt to understand this vast variety Planetarium as well as a eventually led to the physics of the structure of the stars. Science Centre. After obtaining her PhD on The brightness of a star is measured in magnitudes. Hipparchus, Wolf-Rayet stars from the a Greek astronomer who lived a hundred and fifty years before Indian Institute of Astrophysics, she Christ, devised the magnitude system that is still in use today continued research on for the measurement of the brightness of stars (and other celes­ novae, peculiar stars and tial bodies). Since the response of the human eye is logarithmic comets. She is also rather than linear in nature, the system of magnitudes based on actively engaged in teaching and writing visual estimates is on a logarithmic scale (Box 1). This scale was essays on scientific topics put on a quantitative basis by N R Pogson (he was the Director to reach students. of Madras Observatory) more than 150 years ago. The apparent magnitude does not take into account the distance of the star. Therefore, it does not give any idea of the intrinsic brightness of the star. If we could keep all the stars at the same 1 Parsec is a natural unit of dis­ distance, the apparent magnitude itself can give a measure of the tance used in astronomy.
    [Show full text]
  • Naked-Eye Astronomy: Optics of the Starry Night Skies
    Naked-eye Astronomy: Optics of the starry night skies Salva Bará Universidade de Santiago de Compostela, Optics Area, Applied Physics Dept, Faculty of Optics and Optometry, 15782 Santiago de Compostela, Galicia (Spain, European Union) [email protected] ABSTRACT The world at night offers a wealth of stimuli and opportunities as a resource for Optics education, at all age levels and from any (formal, non formal or informal) perspective. The starry sky and the urban nightscape provide a unique combination of pointlike sources with extremely different emission spectra and brightness levels on a generally darker, locally homogeneous background. This fact, combined with the particular characteristics of the human visual system under mesopic and scotopic conditions, provides a perfect setting for experiencing first-hand different optical phenomena of increasing levels of complexity: from the eye's point spread function to the luminance contrast threshold for source detection, from basic diffraction patterns to the intricate irradiance fluctuations due to atmospheric turbulence. Looking at the nightscape is also a perfect occasion to raise awareness on the increasing levels of light pollution associated to the misuse of public and private artificial light at night, to promote a sustainable use of lighting, and to take part in worldwide citizen science campaigns. Last but not least, night sky observing activities can be planned and developed following a very flexible schedule, allowing individual students to carry them out from home and sharing the results in the classroom as well as organizing social events and night star parties with the active engagement of families and groups of the local community.
    [Show full text]
  • Sky, Celestial Sphere and Constellations Last Lecture
    Sky, Celestial Sphere and Constellations Last lecture • Galaxies are the main building blocks of the universe. – Consists of few billions to hundreds of billions of stars , gas clouds (nebulae), star clusters, debris from dead stars … – Few hundreds of thousands of light years in size – Shapes spiral, elliptic, irregular • Our galaxy: Milky way a spiral galaxy 100,000 LY in size, 100 billion stars with many satellite galaxies. • Galaxies group together, local clusters, clusters, super clusters of galaxies • Largest scale they from a filamentary/wall like structure: cosmic web – Largest scales universe homogeneous , isotropic • Universe is 13.8 years old, first stars/galaxies formed 400M years after that. • So oldest galaxies 13.4 billion years old, at a distance 13.4 billion LY away. • Regions beyond that are not visible to us, light from those regions has not reached us yet. Earth and the Sky this part of the sky visible here sunlight this part of the sky visible here • The side of the Earth facing sun at a give time gets sunlight and it is daytime. • The other side facing away for the sun is experiencing nighttime. • During the day, sky looks blue, at night sky is dark and we can see stars and other celestial objects in the sky. • At a given time and a given location only half of the sky is visible. • On a typical moonless clear night about 3000 stars are visible. Blue Sky during the day Sun more less scattering scattering Earth atmosphere • During the day we can not see stars due to glare of the atmosphere (from sunlight) • When light fall on air molecules (particles) some of the light get scattered (ie.
    [Show full text]
  • Indigenous Use of Stellar Scintillation to Predict Weather and Seasonal Change
    Preprint – Proceedings of the Royal Society of Victoria Indigenous use of stellar scintillation to predict weather and seasonal change Duane W. Hamacher 1,2, John Barsa 3, Segar Passi 3, and Alo Tapim 3 1 Monash Indigenous Studies Centre, Monash University, Clayton VIC 3800, Australia 2 Mount Burnett Observatory, 420 Paternoster Rd, Mount Burnett VIC 3781, Australia 3 Meriam Elder, Murray Island, QLD, 4875, Australia Corresponding Author Email: [email protected] Abstract Indigenous peoples across the world observe the motions and positions of stars to de- velop seasonal calendars. Additionally, changing properties of stars, such as their brightness and colour, are also used for predicting weather. Combining archival stud- ies with ethnographic fieldwork in Australia’s Torres Strait, we explore the various ways Indigenous peoples utilise stellar scintillation (twinkling) as an indicator for predicting weather and seasonal change, discussing the scientific underpinnings of this knowledge. By observing subtle changes in the ways the stars twinkle, Meriam people gauge changing trade winds, approaching wet weather, and temperature changes. We then explore how the Northern Dene of Arctic North America utilise stellar scintillation to forecast weather. Keywords Cultural Astronomy; Ethnoastronomy; Indigenous Knowledge; Stellar Scintillation; Torres Strait Islanders 1 Introduction To the general public, the twinkling of stars serves as inspiration for art and poetry. While many Indigenous cultures draw their own poetic and aesthetic inspiration from this phenomenon, current ethnographic fieldwork shows that the twinkling of stars serves an important practical purpose to Indigenous peoples. A person’s ability to ac- curately “read” the various changes in the properties of stars can assist them in pre- dicting weather and seasonal change.
    [Show full text]
  • Nature's Optics and Our Understanding of Light
    Contemporary Physics, 2015 Vol. 56, No. 1, 2–16, http://dx.doi.org/10.1080/00107514.2015.971625 Nature’s optics and our understanding of light M.V. Berry* H H Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK (Received 8 September 2014; accepted 23 September 2014) Optical phenomena visible to everyone have been central to the development of, and abundantly illustrate, important concepts in science and mathematics. The phenomena considered from this viewpoint are rainbows, sparkling reflections on water, mirages, green flashes, earthlight on the moon, glories, daylight, crystals and the squint moon. And the con- cepts involved include refraction, caustics (focal singularities of ray optics), wave interference, numerical experiments, mathematical asymptotics, dispersion, complex angular momentum (Regge poles), polarisation singularities, Hamilton’s conical intersections of eigenvalues (‘Dirac points’), geometric phases and visual illusions. Keywords: refraction; reflection; interference; caustics; focusing; polarisation 1. Introduction because the house in the picture is Isaac Newton’s birth- Natural optical phenomena have been the subject of many place and it was Newton who gave the first explanation studies over many centuries, and have been described of the rainbow’s colours [6]. We will see later why the many times in the technical [1,2] and popular [3–5] litera- picture is ironic as well as iconic. ture. Yet another general presentation would be superflu- To a physicist, the colours are a secondary feature, ous. Instead, as my way of celebrating the International associated mainly with the dependence of refractive Year of Light, this article will have a particular intellectual index of water on wavelength (optical dispersion).
    [Show full text]
  • Star Twinkling
    TEACHER RESOURCE SCIENCE CONTENT/ CURRICULUM LINK PLANET EARTH AND BEYOND – OBSERVING STARS AND STARDOME OBSERVATORY & PLANETARIUM INVESTIGATING FACTS, RESOURCES AND ACTIVITIES ON... IN SCIENCE star twinkling Except for the Sun, stars are too distant to see their round shape. Even astronauts orbiting Earth see Light from a star stars that are just points of light without any edges. Astronauts observe perfectly steady points, unaffected by Earth’s atmosphere. However, we see stars that twinkle to various degrees, producing the dancing, romantic, mysterious faint lights of the nursery song we all know. Atmosphere has ‘Twinkling’ is an effect called scintillation, which is moving pockets of the distortion of starlight by changing air masses. cold and warm air Layers of warmer and cooler air have different densities, which refract (bend) light at different angles. Further scintillation is enhanced by the turbulence of moving and changing air masses. The higher a star is in the sky, the less atmosphere you are looking through. As you observe stars at *not to scale lower altitudes, eventually reaching the horizon, the starlight is traversing Adaptive optics uses increasingly longer paths of celestial images. While there is a technical an artificial star through the atmosphere. procedure for recording the seeing at a location created with lasers. at any particular time, amateur observers often ~~~ The starlight is increasingly use the Pickering Scale. This ranges from ‘1’, where Twinkling is similar distorted, producing more the image is dancing wildly and there is no central to shimmering twinkling, and becoming star point, to ‘10’, where there is a clear completely images above hot dimmer (an effect called roofs and roads on ‘extinction’).
    [Show full text]
  • NATURE April 29, 1950 Vol
    664 NATURE April 29, 1950 Vol. 165 white ones. Such details may perhaps be accounted on the retina will change from lines of coloured dots for by physiology. to coloured streaks as the speed of movement of the M. MINNAERT image increases. This is found to be so. Scintillation Sterrewacht "Sonnenborgh ", is very obvious with bright stars like Sirius down to Utrecht. those in the Pleiades, even in a telescope giving a 'Nature, 164, 999 (1949) and 165, 146 (1950). magnification of x 20. Planets show scarcely any • Mon. Not. Roy . .Astro. Soc., 87, 506 (1927). Stromgren, B., Festskr. trace of this effect. Norlund, 1945; etc. Morton's observation of Sirius through misted 'Minnaert and Houtgast, Z . .Astrophys., 10, 86 (1935). glass can readily be repeated by defocusing, and the defocused image can be moved as before. Scintillation NONE of the correspondents writing on this subject is still visible, and is clearly almost synchronous over appears to have taken into account the fact that, as the whole disk of the image. Although the 'boiling' viewed by most people, most of the stars do not effect mentioned by Gregory shows as an occasional scintillate when observed with the naked eye from fl.ash in the width of the ribbon of light, fl.ashes a point within the tropics. This at any rate is my must cover hundreds of times the retinal area covered clear recollection after spending more than three by the image of the star when in focus. years in the tropical zone. It would be interesting to know what effects could H.
    [Show full text]
  • 365 Starry Nights by Chet Raymo Detailed Contents
    365 STARRY NIGHTS BY CHET RAYMO DETAILED CONTENTS DATE CONSTELLATION TOPIC JANUARY 1 Winter Hexagon Zenith, Winter Hexagon 2 Orion Orion’s Belt 3 Celestial Equator 4 Celestial Sphere, Arabic Names 5 Celestial Sphere, Degree Measurements 6 “ “ “ “ 7 Turning of the Stars (24h = 360o) 8 Seasonal Turning of Stars 9 Apparent Magnitude 10 “ “ 11 Horsehead Nebula 12 Great Nebula 13 “ “ 14 “ “ 15 Red Giants 16 “ “ 17 Taurus Signs of the Zodiac 18 Aldebaran 19 Elliptic, Zodiac, Occultation 20 “ “ “ 21 Light Year, Distance to Pleiades, Hyades 22 “ “ “ “ “ “ 23 Pleiades 24 “ 25 Open Clusters, Proper Motion 26 Crab Nebula 27 White Dwarf 28 Neutron Star, Pulsar 29 Auriga Auriga 30 Capella, The Kids 31 ε Aurigae 365 STARRY NIGHTS BY CHET RAYMO DETAILED CONTENTS DATE CONSTELLATION TOPIC FEBRUARY 1 Canis Major Twinkling, Sirius 2 Orions & Pals Animal Companions: Dogs & Hare 3 Canis Major Mirzam 4 Sirius 5 Close Stars 6 Sirius & Myths 7 Star Colors, Planck Curve 8 Light Spectrum 9 Line Spectra, Spectral Types 10 Mysterious Sirius B 11 “ “ “ 12 “ “ “ 13 “ “ “ 14 “ “ “ 15 Canis Minor Canis Minor 16 Procyon, Gomeisa 17 Procyon’s Proper Motion, Name 18 “ “ “ “ 19 Milky Way, Rosette Nebula 20 Monocerous Cone Nebula 21 Gemini Castor & Pollux, Ying & Yang 22 “ “ “ “ “ “ 23 Castor - Multiple Star System 24 Pollux 25 Zodiac, Summer Solstice 26 Planet Discoveries 27 U Geminorum 28 Eskimo Nebula - Planetary Nebula 365 STARRY NIGHTS BY CHET RAYMO DETAILED CONTENTS DATE CONSTELLATION TOPIC MARCH 1 Various Oblers’ Paradox 2 “ “ 3 Alphard 4 “ 5 Cancer Stars of Cancer,
    [Show full text]