Links to Education Standards • Introduction to Exoplanets • Glossary of Terms • Classroom Activities Table of Contents Photo © Michael Malyszko Photo © Michael
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Photochemically Driven Collapse of Titan's Atmosphere
REPORTS has escaped, the surface temperature again Photochemically Driven Collapse decreases, down to about 86 K, slightly of Titan’s Atmosphere above the equilibrium temperature, because of the slight greenhouse effect resulting Ralph D. Lorenz,* Christopher P. McKay, Jonathan I. Lunine from the N2 opacity below (longward of) 200 cm21. Saturn’s giant moon Titan has a thick (1.5 bar) nitrogen atmosphere, which has a These calculations assume the present temperature structure that is controlled by the absorption of solar and thermal radiation solar constant of 15.6 W m22 and a surface by methane, hydrogen, and organic aerosols into which methane is irreversibly converted albedo of 0.2 and ignore the effects of N2 by photolysis. Previous studies of Titan’s climate evolution have been done with the condensation. As noted in earlier studies assumption that the methane abundance was maintained against photolytic depletion (5), when the atmosphere cools during the throughout Titan’s history, either by continuous supply from the interior or by buffering CH4 depletion, the model temperature at by a surface or near surface reservoir. Radiative-convective and radiative-saturated some altitudes in the atmosphere (here, at equilibrium models of Titan’s atmosphere show that methane depletion may have al- ;10 km for 20% CH4 surface humidity) lowed Titan’s atmosphere to cool so that nitrogen, its main constituent, condenses onto becomes lower than the saturation temper- the surface, collapsing Titan into a Triton-like frozen state with a thin atmosphere. -
A Spectroscopic Atlas of Deneb (A2 Iae) $\Lambda\Lambda$3826–5212
A&A 400, 1043–1049 (2003) Astronomy DOI: 10.1051/0004-6361:20030014 & c ESO 2003 Astrophysics A spectroscopic atlas of Deneb (A2 Iae) λλ3826–5212? B. Albayrak1,A.F.Gulliver2,??,S.J.Adelman3,??, C. Aydın1,andD.Ko¸cer4 1 Ankara University, Science Faculty, Department of Astronomy and Space Sciences, 06100, Tando˘gan, Ankara, Turkey e-mail: [email protected]; [email protected] 2 Department of Physics and Astronomy, Brandon University, Brandon, MB, R7A 6A9, Canada e-mail: [email protected] 3 Department of Physics, The Citadel, 171 Moultrie Street, Charleston, SC 29409, USA e-mail: [email protected] 4 Istanbul˙ K¨ult¨ur University, Science & Art Faculty, Department of Mathematics, E5 Karayolu Uzeri,¨ 34510, S¸irinevler, Istanbul,˙ Turkey e-mail: [email protected] Received 2 December 2002 / Accepted 6 January 2003 Abstract. We present a spectroscopic atlas of Deneb (A2 Iae) obtained with the long camera of the 1.22-m telescope of the 1 Dominion Astrophysical Observatory using Reticon and CCD detectors. For λλ3826–5212 the inverse dispersion is 2.4 Å mm− with a resolution of 0.072 Å. At the continuum the mean signal-to-noise ratio is 1030. The wavelengths in the laboratory frame, the equivalent widths, and the identifications of the various spectral features are given. This atlas should provide useful guidance for studies of other stars with similar spectral types. The stellar and synthetic spectra with their corresponding line identifications can be examined at http://www.brandonu.ca/physics/gulliver/atlases.html Key words. atlases – stars: early type – stars: individual: Deneb – stars: supergiants 1. -
SEPTEMBER 2014 OT H E D Ebn V E R S E R V ESEPTEMBERR 2014
THE DENVER OBSERVER SEPTEMBER 2014 OT h e D eBn v e r S E R V ESEPTEMBERR 2014 FROM THE INSIDE LOOKING OUT Calendar Taken on July 25th in San Luis State Park near the Great Sand Dunes in Colorado, Jeff made this image of the Milky Way during an overnight camping stop on the way to Santa Fe, NM. It was taken with a Canon 2............................. First quarter moon 60D camera, an EFS 15-85 lens, using an iOptron SkyTracker. It is a single frame, with no stacking or dark/ 8.......................................... Full moon bias frames, at ISO 1600 for two minutes. Visible in this south-facing photograph is Sagittarius, and the 14............ Aldebaran 1.4˚ south of moon Dark Horse Nebula inside of the Milky Way. He processed the image in Adobe Lightroom. Image © Jeff Tropeano 15............................ Last quarter moon 22........................... Autumnal Equinox 24........................................ New moon Inside the Observer SEPTEMBER SKIES by Dennis Cochran ygnus the Swan dives onto center stage this other famous deep-sky object is the Veil Nebula, President’s Message....................... 2 C month, almost overhead. Leading the descent also known as the Cygnus Loop, a supernova rem- is the nose of the swan, the star known as nant so large that its separate arcs were known Society Directory.......................... 2 Albireo, a beautiful multi-colored double. One and named before it was found to be one wide Schedule of Events......................... 2 wonders if Albireo has any planets from which to wisp that came out of a single star. The Veil is see the pair up-close. -
The Midnight Sky: Familiar Notes on the Stars and Planets, Edward Durkin, July 15, 1869 a Good Way to Start – Find North
The expression "dog days" refers to the period from July 3 through Aug. 11 when our brightest night star, SIRIUS (aka the dog star), rises in conjunction* with the sun. Conjunction, in astronomy, is defined as the apparent meeting or passing of two celestial bodies. TAAS Fabulous Fifty A program for those new to astronomy Friday Evening, July 20, 2018, 8:00 pm All TAAS and other new and not so new astronomers are welcome. What is the TAAS Fabulous 50 Program? It is a set of 4 meetings spread across a calendar year in which a beginner to astronomy learns to locate 50 of the most prominent night sky objects visible to the naked eye. These include stars, constellations, asterisms, and Messier objects. Methodology 1. Meeting dates for each season in year 2018 Winter Jan 19 Spring Apr 20 Summer Jul 20 Fall Oct 19 2. Locate the brightest and easiest to observe stars and associated constellations 3. Add new prominent constellations for each season Tonight’s Schedule 8:00 pm – We meet inside for a slide presentation overview of the Summer sky. 8:40 pm – View night sky outside The Midnight Sky: Familiar Notes on the Stars and Planets, Edward Durkin, July 15, 1869 A Good Way to Start – Find North Polaris North Star Polaris is about the 50th brightest star. It appears isolated making it easy to identify. Circumpolar Stars Polaris Horizon Line Albuquerque -- 35° N Circumpolar Stars Capella the Goat Star AS THE WORLD TURNS The Circle of Perpetual Apparition for Albuquerque Deneb 1 URSA MINOR 2 3 2 URSA MAJOR & Vega BIG DIPPER 1 3 Draco 4 Camelopardalis 6 4 Deneb 5 CASSIOPEIA 5 6 Cepheus Capella the Goat Star 2 3 1 Draco Ursa Minor Ursa Major 6 Camelopardalis 4 Cassiopeia 5 Cepheus Clock and Calendar A single map of the stars can show the places of the stars at different hours and months of the year in consequence of the earth’s two primary movements: Daily Clock The rotation of the earth on it's own axis amounts to 360 degrees in 24 hours, or 15 degrees per hour (360/24). -
Detection and Characterization of Hot Subdwarf Companions of Massive Stars Luqian Wang
Georgia State University ScholarWorks @ Georgia State University Physics and Astronomy Dissertations Department of Physics and Astronomy 8-13-2019 Detection And Characterization Of Hot Subdwarf Companions Of Massive Stars Luqian Wang Follow this and additional works at: https://scholarworks.gsu.edu/phy_astr_diss Recommended Citation Wang, Luqian, "Detection And Characterization Of Hot Subdwarf Companions Of Massive Stars." Dissertation, Georgia State University, 2019. https://scholarworks.gsu.edu/phy_astr_diss/119 This Dissertation is brought to you for free and open access by the Department of Physics and Astronomy at ScholarWorks @ Georgia State University. It has been accepted for inclusion in Physics and Astronomy Dissertations by an authorized administrator of ScholarWorks @ Georgia State University. For more information, please contact [email protected]. DETECTION AND CHARACTERIZATION OF HOT SUBDWARF COMPANIONS OF MASSIVE STARS by LUQIAN WANG Under the Direction of Douglas R. Gies, PhD ABSTRACT Massive stars are born in close binaries, and in the course of their evolution, the initially more massive star will grow and begin to transfer mass and angular momentum to the gainer star. The mass donor star will be stripped of its outer envelope, and it will end up as a faint, hot subdwarf star. Here I present a search for the subdwarf stars in Be binary systems using the International Ultraviolet Explorer. Through spectroscopic analysis, I detected the subdwarf star in HR 2142 and 60 Cyg. Further analysis led to the discovery of an additional 12 Be and subdwarf candidate systems. I also investigated the EL CVn binary system, which is the prototype of class of eclipsing binaries that consist of an A- or F-type main sequence star and a low mass subdwarf. -
Light, Color, and Atmospheric Optics
Light, Color, and Atmospheric Optics GEOL 1350: Introduction To Meteorology 1 2 • During the scattering process, no energy is gained or lost, and therefore, no temperature changes occur. • Scattering depends on the size of objects, in particular on the ratio of object’s diameter vs wavelength: 1. Rayleigh scattering (D/ < 0.03) 2. Mie scattering (0.03 ≤ D/ < 32) 3. Geometric scattering (D/ ≥ 32) 3 4 • Gas scattering: redirection of radiation by a gas molecule without a net transfer of energy of the molecules • Rayleigh scattering: absorption extinction 4 coefficient s depends on 1/ . • Molecules scatter short (blue) wavelengths preferentially over long (red) wavelengths. • The longer pathway of light through the atmosphere the more shorter wavelengths are scattered. 5 • As sunlight enters the atmosphere, the shorter visible wavelengths of violet, blue and green are scattered more by atmospheric gases than are the longer wavelengths of yellow, orange, and especially red. • The scattered waves of violet, blue, and green strike the eye from all directions. • Because our eyes are more sensitive to blue light, these waves, viewed together, produce the sensation of blue coming from all around us. 6 • Rayleigh Scattering • The selective scattering of blue light by air molecules and very small particles can make distant mountains appear blue. The blue ridge mountains in Virginia. 7 • When small particles, such as fine dust and salt, become suspended in the atmosphere, the color of the sky begins to change from blue to milky white. • These particles are large enough to scatter all wavelengths of visible light fairly evenly in all directions. -
Project Horizon Report
Volume I · SUMMARY AND SUPPORTING CONSIDERATIONS UNITED STATES · ARMY CRD/I ( S) Proposal t c• Establish a Lunar Outpost (C) Chief of Ordnance ·cRD 20 Mar 1 95 9 1. (U) Reference letter to Chief of Ordnance from Chief of Research and Devel opment, subject as above. 2. (C) Subsequent t o approval by t he Chief of Staff of reference, repre sentatives of the Army Ballistic ~tissiles Agency indicat e d that supplementar y guidance would· be r equired concerning the scope of the preliminary investigation s pecified in the reference. In particular these r epresentatives requested guidance concerning the source of funds required to conduct the investigation. 3. (S) I envision expeditious development o! the proposal to establish a lunar outpost to be of critical innportance t o the p. S . Army of the future. This eva luation i s appar ently shar ed by the Chief of Staff in view of his expeditious a pproval and enthusiastic endorsement of initiation of the study. Therefore, the detail to be covered by the investigation and the subs equent plan should be as com plete a s is feas ible in the tin1e limits a llowed and within the funds currently a vailable within t he office of t he Chief of Ordnance. I n this time of limited budget , additional monies are unavailable. Current. programs have been scrutinized r igidly and identifiable "fat'' trimmed awa y. Thus high study costs are prohibitive at this time , 4. (C) I leave it to your discretion t o determine the source and the amount of money to be devoted to this purpose. -
Atmospheric Optics
53 Atmospheric Optics Craig F. Bohren Pennsylvania State University, Department of Meteorology, University Park, Pennsylvania, USA Phone: (814) 466-6264; Fax: (814) 865-3663; e-mail: [email protected] Abstract Colors of the sky and colored displays in the sky are mostly a consequence of selective scattering by molecules or particles, absorption usually being irrelevant. Molecular scattering selective by wavelength – incident sunlight of some wavelengths being scattered more than others – but the same in any direction at all wavelengths gives rise to the blue of the sky and the red of sunsets and sunrises. Scattering by particles selective by direction – different in different directions at a given wavelength – gives rise to rainbows, coronas, iridescent clouds, the glory, sun dogs, halos, and other ice-crystal displays. The size distribution of these particles and their shapes determine what is observed, water droplets and ice crystals, for example, resulting in distinct displays. To understand the variation and color and brightness of the sky as well as the brightness of clouds requires coming to grips with multiple scattering: scatterers in an ensemble are illuminated by incident sunlight and by the scattered light from each other. The optical properties of an ensemble are not necessarily those of its individual members. Mirages are a consequence of the spatial variation of coherent scattering (refraction) by air molecules, whereas the green flash owes its existence to both coherent scattering by molecules and incoherent scattering -
Binary Asteroids and the Formation of Doublet Craters
ICARUS 124, 372±391 (1996) ARTICLE NO. 0215 Binary Asteroids and the Formation of Doublet Craters WILLIAM F. BOTTKE,JR. Division of Geological and Planetary Sciences, California Institute of Technology, Mail Code 170-25, Pasadena, California 91125 E-mail: [email protected] AND H. JAY MELOSH Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721 Received April 29, 1996; revised August 14, 1996 found we could duplicate the observed fraction of doublet cra- At least 10% (3 out of 28) of the largest known impact craters ters found on Earth, Venus, and Mars. Our results suggest on Earth and a similar fraction of all impact structures on that any search for asteroid satellites should place emphasis Venus are doublets (i.e., have a companion crater nearby), on km-sized Earth-crossing asteroids with short-rotation formed by the nearly simultaneous impact of objects of compa- periods. 1996 Academic Press, Inc. rable size. Mars also has doublet craters, though the fraction found there is smaller (2%). These craters are too large and too far separated to have been formed by the tidal disruption 1. INTRODUCTION of an asteroid prior to impact, or from asteroid fragments dispersed by aerodynamic forces during entry. We propose that Two commonly held paradigms about asteroids and some fast rotating rubble-pile asteroids (e.g., 4769 Castalia), comets are that (a) they are composed of non-fragmented after experiencing a close approach with a planet, undergo tidal chunks of rock or rock/ice mixtures, and (b) they are soli- breakup and split into multiple co-orbiting fragments. -
Humanity and Space
10/17/2012!! !!!!!! Project Number: MH-1207 Humanity and Space An Interactive Qualifying Project Submitted to WORCESTER POLYTECHNIC INSTITUTE In partial fulfillment for the Degree of Bachelor of Science by: Matthew Beck Jillian Chalke Matthew Chase Julia Rugo Professor Mayer H. Humi, Project Advisor Abstract Our IQP investigates the possible functionality of another celestial body as an alternate home for mankind. This project explores the necessary technological advances for moving forward into the future of space travel and human development on the Moon and Mars. Mars is the optimal candidate for future human colonization and a stepping stone towards humanity’s expansion into outer space. Our group concluded space travel and interplanetary exploration is possible, however international political cooperation and stability is necessary for such accomplishments. 2 Executive Summary This report provides insight into extraterrestrial exploration and colonization with regards to technology and human biology. Multiple locations have been taken into consideration for potential development, with such qualifying specifications as resources, atmospheric conditions, hazards, and the environment. Methods of analysis include essential research through online media and library resources, an interview with NASA about the upcoming Curiosity mission to Mars, and the assessment of data through mathematical equations. Our findings concerning the human aspect of space exploration state that humanity is not yet ready politically and will not be able to biologically withstand the hazards of long-term space travel. Additionally, in the field of robotics, we have the necessary hardware to implement adequate operational systems yet humanity lacks the software to implement rudimentary Artificial Intelligence. Findings regarding the physics behind rocketry and space navigation have revealed that the science of spacecraft is well-established. -
The Terrestrial Planet V Hypothesis As the Mechanism for the Origin of the Late Heavy Bombardment
A&A 535, A41 (2011) Astronomy DOI: 10.1051/0004-6361/201117336 & c ESO 2011 Astrophysics The terrestrial Planet V hypothesis as the mechanism for the origin of the late heavy bombardment R. Brasser and A. Morbidelli Dep. Cassiopée, University of Nice–Sophia Antipolis, CNRS, Observatoire de la Côte d’Azur, 06304 Nice, France e-mail: [email protected] Received 24 May 2011 / Accepted 13 September 2011 ABSTRACT In this study we attempt to model, with numerical simulations, the scenario for the origin of the late heavy bombardment (LHB) proposed in Chambers (2007, Icarus, 189, 386). Chambers suggested that the orbit of a fictitious sub-Mars sized embryo outside Mars became unstable and crossed a part of the asteroid belt until it was removed through ejection or collision. Chambers demonstrated that this kind of evolution can occur at the LHB time, but he did not check whether enough material could be liberated from the belt to be consistent with the magnitude of the LHB. We do that here. In addition to the asteroid belt, we also consider putative belts of small objects located between the orbits of the Earth and Venus (EV belt) or between the Earth and Mars (EM belt). We find that delivering enough material to the Moon from the asteroid belt requires at least a 5 lunar mass embryo crossing the entire asteroid belt up to 3.3 AU for longer than 300 Myr on a low-inclination orbit. We do not witness this to occur in over a hundred simulations. An alternative approach, which relies only on decimating the inner belt (<2.5 AU), requires that the inner belt originally contained 4 to 13 times more mass than the original outer belt. -
Chapter 11: Atmosphere
The Atmosphere and the Oceans ff the Na Pali coast in Hawaii, clouds stretch toward O the horizon. In this unit, you’ll learn how the atmo- sphere and the oceans interact to produce clouds and crashing waves. You’ll come away from your studies with a deeper understanding of the common characteristics shared by Earth’s oceans and its atmosphere. Unit Contents 11 Atmosphere14 Climate 12 Meteorology15 Physical Oceanography 13 The Nature 16 The Marine Environment of Storms Go to the National Geographic Expedition on page 880 to learn more about topics that are con- nected to this unit. 268 Kauai, Hawaii 269 1111 AAtmospheretmosphere What You’ll Learn • The composition, struc- ture, and properties that make up Earth’s atmos- phere. • How solar energy, which fuels weather and climate, is distrib- uted throughout the atmosphere. • How water continually moves between Earth’s surface and the atmo- sphere in the water cycle. Why It’s Important Understanding Earth’s atmosphere and its interactions with solar energy is the key to understanding weather and climate, which con- trol so many different aspects of our lives. To find out more about the atmosphere, visit the Earth Science Web Site at earthgeu.com 270 DDiscoveryiscovery LLabab Dew Formation Dew forms when moist air near 4. Repeat the experiment outside. the ground cools and the water vapor Record the temperature of the in the air changes into water droplets. water and the air outside. In this activity, you will model the Observe In your science journal, formation of dew. describe what happened to the out- 1.