DOCSLIB.ORG

Durham E-Theses

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Durham E-Theses Durham E-Theses A polarimetric study of the reection nebulae NGC 2068 and NGC 2023 in the Orion R1 association Mannion, Michael David How to cite: Mannion, Michael David (1987) A polarimetric study of the reection nebulae NGC 2068 and NGC 2023 in the Orion R1 association, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/6892/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 A polarimetric study of the reflection nebulae NGC 2068 and NGC 2023 in the Orion R1 association The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. Michael David Mannion Department of Physics University of Durham Science Laboratories South Road Durham DH1 3LE A thesis subrnitted to the University of Durham for the degree of Doctor of Philosophy 30 January 1987 A polarimetric study of the reflection nebulae NGC 2068 and NGC 2023 in the Orion R1 association Michael David Mannion ABSTRACT Polarimetry studies of two reflection nebulae in the Orion R1 association are used to determine the nature of the dust in which recently formed stars are embedded in, and show the geometry of the surrounding dust cloud. The data reductions presented are on NGC 2068 and NGC 2023, which are centres of recent low-mass star formation and are embedded on the nearside of 11630. In the case of NGC 2068, it appears that there is a single illuminating star which illuminates a foreground tilted slab of varying dust density from the rear. A simple tilted slab model assuming single Mie scattering from homogeneous spherical grains was used to fit visual data of traces of polarization, polarized intensity and total intensity through HD 38563N in a north-south direction. The model favoured metallic grains; the best fit being for iron grains and a slab 0.5 parsecs in front of HD 38563N tilted at an angle 55 degrees to the line-of-sight. In the case of NGC 2023, multicolour polarimetry is presented in B,V,R,I and z. The star HD 37903 was found to be the sole illuminating star. A model to fit the spectral dependence of polarization gave low refractive index grains assuming a power law size distribution. Associated with NGC 2023 are Herbig-Haro objects HH-1, 4, which were found not to be polarized. Ph.D. Thesis PAGE i January 1987 PREFACE The work undertaken for this doctoral thesis was done while the author was a postgraduate member of the Astronany Group in the Department of Physics at Durham University under the supervision of Dr. S.M. Scarrott between February 1983 and January 1987. During this time the author reduced and analysed electronographic polarimetry data on NGC 2068 in the V waveband, and electronographic (B,V,R) and CCD (R,I,Z) data on NGC 2023. Mcdels were devised to fit a) the observations of visual polarization in NGC 2068 as a function of offset distance and b) the observed wavelength dependence of polarization in NGC 2023. No part of this thesis has previously been submitted for a degree in this or any other university and all work is due to the author unless otherwise acknowledged. The copyright of this thesis rests with the author. No quotation fran it should be published without his prior written consent and information derived from it should be acknowledged. Michael David Mannion Ph.D. Thesis PAGE ii January 1 987 Cl)NTENTS Page ABSTRACI' i PREFACE ii TABLES viii LIST OF FIGURES X LIST OF PLATES xiii Chapter 1 Intrcrluction 1 1 01 Observations 1 1o2 Star fonnation 3 1o3 The Orion Complex 8 1o4 Reflection nebulae 14 . 1 oS Interstellar dust grains 19 1o6 Polarimetry 20 1o7 Aims 26 PhoDo Thesis PAGE iii January 1987 CDNT.ENTS Page Chapter 2 Interstellar Dust Grains 28 2.1 Introduction 28 2.2 Data on dust grains 33 2.2 a Extinction 35 2.2 b Polarization 39 2.2 c Spectroscopy 43 2.2 d Scattering 44 2.2 e Distribution 46 2.2 f Dust-to-gas ratio 46 2.2 g Physical properties 48 2.3 Grain models 50 2.4 Fonnation, growth and destruction 54 2.5 Dust interactions in the interstellar medium 57 2.6 Conclusions 58 Chapter 3 Star Fonnation 62 3.1 Theories of star fonnation 62 3.2 Signposts of star fonnation 79 3.3 Star fonnation in the 84 Orion Molecular Cloud Complex Ph.D. Thesis PAGE iv January 1987 <X>NTENTS Page Chapter 4 Polarimetry of NGC 2068 89 4a1 Introduction 89 4 a2 Summary of previous work 92 4a3 New observations 96 4a4 The polarimetry data 97 4a5 Discussion 114 Chapter 5 A Model of NGC 2068 120 5a1 Tilted slab 120 5a2 Immediate enviroment in NGC 2068 131 5a3 Discussion 138 Chapter 6 Polarimetry of NGC 2023 139 6a 1 Optical and near-infrared 139 polarimetry of NGC 2023 6a1 a Electronographic data 145 6o 1 b CCD data 152 PhaDo Thesis PAGE V January 1987 CDNTENTS Page 6.2 Comparison of C<D and Electronographic 160 data on NGC 2023 6.3 Wavelength dependence of polarization 164 6.4 IRAS data 170 6.5 The optical filament and HH-1 173 6.6 Discussion 175 Chapter 7 Analysis of NGC 2023 180 7.1 Physical conditions in NGC 2023 180 7.2 Morphology and structure of NGC 2023 187 7.3 The star S1 08 and HH-1 190 7.4 Extended emission 195 7.5 Inferences on dust 195 Chapter 8 Conclusions 202 8.1 Interpreting the main observations of 202 NGC 2068 and NGC 2023 Ph.D. Thesis PAGE vi January 1987 CDNTENTS Page Summary 206 ACKNOWLEDGEMENTS 208 LIST OF SYMBOLS 209 REFERENCES 210 APPENDICES 230 A An optical polarization study of NGC 2068 230 B A comparison of data reductions of NGC 2068 243 C Linear traces through HD 37903 244 Ph.D. Thesis PAGE vii January 1987 TABLES Page Table 1.1 The Orion R1 association 16 1 • 2 A cx:mparison of CCD and electronographic detectors 25 2. 1 The interstellar medium 30 2. 2 Infrared features of dust grains 44 2.3 Reflection nebula models 51-52 2.4 Interstellar dust grains 61 4.1 r::ata on the stars associated with NGC 2068 90 4. 2 Previous polarimetry of NGC 2068 94-96 4. 3 Infrared stars associated with NGC 2068 102 4.4 Polarization of selected regions of NGC 2068 106 5.1 Grain materials 123 5.2 Grid of models 130 5. 3 Physical parameters of NGC 2068 137 Ph.D. Thesis PAGE viii January 1987 TABLES Page Table 6.1 Filter characteristics 140 6.2 Data on the stars associated with NGC 2023 143 6.3 Identification of stars on Electronographic data 147 6.4 Identification of stars from CCD data 154 6.5a Multicolour polarimetry of NGC 2023 162 6.5b Multicolour polarimetry of NGC 2023 163 6.6 Stars common to COD and Electronographic data 164 6.7a Multicolour polarimetry of NGC 2023 168 6.7b Multicolour polarimetry of NGC 2023 169 6.8 Polarimetry of regions close to S108 175 7. 1 Physical parameters of NGC 2023 186 7.2 Best fits to the wavelength dependence of polarization 197 8.1 Summary of reflection nebula observations 207 Ph.D. Thesis PAGE ix January 1987 LIST OF FIGURES Page Figure 1 • 1 The Orion molecular canplexes 10 1 .2 The dark dust cloud - Lynds 1630 12 1 • 3 Manifestations of star fonna.tion near the M78 canplex 13 1.4 Galactic distribution of Rand OB associations 15 2.1 The interstellar extinction curve 38 2.2 Interstellar polarization 41 3.1 Sequential star fonna.tion in OB associations 68 3.2 Evolutionary tracks of collapsing protostars 73 4.1 A visual polarization map of NGC 2068 100 4.2 A map of the region of NGC 2068 103 4.3 Polarization trace through HD 38563N 110 in a north-south direction 4.4 Polarized intensity trace through HD 38563N 111 in a north-south direction 4.5 'Ibtal intensity trace through HD 38563N 112 in a north-south direction 4.6 Arc traces about HD 38563N 113 Ph.D. Thesis PAGE x January 1987 LIST OF FIGURES Page Figure 4.7 Tilted slab model 119 5.1 Geometry of the tilted slab model 122 5. 2 Mie scattering curves 126-129 5.3a Model fits to the data - Polarization 132 5.3b Model fits to the data - Polarized intensity 133 5.3c Model fits to the data - Total intensity 134 6. 1 A map of the stars in the region of NGC 2023 144 6.2 Polarization of NGC 2023 using a B filter 149 6.3 Polarization of NGC 2023 using a V filter 150 6.4 Polarization of NGC 2023 using an R filter 151 6.5 Polarization of NGC 2023 using an R filter 157 6.6 Polarization of NGC 2023 using an I filter 158 6.7 Polarization of NGC 2023 using a z filter 159 6.8a Wavelength dependence of polarization 166 6.8b Wavelength dependence of polarization 167 6.9a Wavelength dependence of position angle 171 6.9b Wavelength dependence of position angle 172 6.10 A polarization and contour map of the S108 region 176 Ph.D.
Load more

Recommended publications
  • Planetary Nebula
    How Far Away Is It – Planetary Nebula Planetary Nebula {Abstract – In this segment of our “How far away is it” video book, we cover Planetary Nebula. We begin by introducing astrophotography and how it adds to what we can see through a telescope with our eyes. We use NGC 2818 to illustrate how this works. This continues into the modern use of Charge-Coupled Devices and how they work. We use the planetary nebula MyCn18 to illustrate the use of color filters to identify elements in the nebula. We then show a clip illustrating the end-of-life explosion that creates objects like the Helix Planetary Nebula (NGC 7293), and show how it would fill the space between our Sun and our nearest star, Proxima Centauri. Then, we use the Cat’s Eye Nebula (NGC 6543) to illustrate expansion parallax. As a fundamental component for calculating expansion parallax, we also illustrate the Doppler Effect and how we measure it via spectral line red and blue shifts. We continue with a tour of the most beautiful planetary nebula photographed by Hubble. These include: the Dumbbell Nebula, NGC 5189, Ring Nebula, Retina Nebula, Red Rectangle, Ant Nebula, Butterfly Nebula, , Kohoutek 4- 55, Eskimo Nebula, NGC 6751, SuWt 2, Starfish, NGC 5315, NGC 5307, Little Ghost Nebula, NGC 2440, IC 4593, Red Spider, Boomerang, Twin Jet, Calabash, Gomez’s Hamburger and others culminating with a dive into the Necklace Nebula. We conclude by noting that this will be the most likely end for our Sun, but not for billions of years to come, and we update the Cosmic Distance Ladder with the new ‘Expansion Parallax’ rung developed in this segment.} Introduction [Music @00:00 Bizet, Georges: Entracte to Act III from “Carman”; Orchestre National de France / Seiji Ozawa, 1984; from the album “The most relaxing classical album in the world…ever!”] Planetary Nebulae represent some of the most beautiful objects in the Milky Way.
    [Show full text]
  • Winter Constellations
    Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great ​ ​ hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar ​ ​ ​ nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. ​ ​ 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming ​ “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the ​ Orion Nebula.
    [Show full text]
  • 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).
    [Show full text]
  • List of Bright Nebulae Primary I.D. Alternate I.D. Nickname
    List of Bright Nebulae Alternate Primary I.D. Nickname I.D. NGC 281 IC 1590 Pac Man Neb LBN 619 Sh 2-183 IC 59, IC 63 Sh2-285 Gamma Cas Nebula Sh 2-185 NGC 896 LBN 645 IC 1795, IC 1805 Melotte 15 Heart Nebula IC 848 Soul Nebula/Baby Nebula vdB14 BD+59 660 NGC 1333 Embryo Neb vdB15 BD+58 607 GK-N1901 MCG+7-8-22 Nova Persei 1901 DG 19 IC 348 LBN 758 vdB 20 Electra Neb. vdB21 BD+23 516 Maia Nebula vdB22 BD+23 522 Merope Neb. vdB23 BD+23 541 Alcyone Neb. IC 353 NGC 1499 California Nebula NGC 1491 Fossil Footprint Neb IC 360 LBN 786 NGC 1554-55 Hind’s Nebula -Struve’s Lost Nebula LBN 896 Sh 2-210 NGC 1579 Northern Trifid Nebula NGC 1624 G156.2+05.7 G160.9+02.6 IC 2118 Witch Head Nebula LBN 991 LBN 945 IC 405 Caldwell 31 Flaming Star Nebula NGC 1931 LBN 1001 NGC 1952 M 1 Crab Nebula Sh 2-264 Lambda Orionis N NGC 1973, 1975, Running Man Nebula 1977 NGC 1976, 1982 M 42, M 43 Orion Nebula NGC 1990 Epsilon Orionis Neb NGC 1999 Rubber Stamp Neb NGC 2070 Caldwell 103 Tarantula Nebula Sh2-240 Simeis 147 IC 425 IC 434 Horsehead Nebula (surrounds dark nebula) Sh 2-218 LBN 962 NGC 2023-24 Flame Nebula LBN 1010 NGC 2068, 2071 M 78 SH 2 276 Barnard’s Loop NGC 2149 NGC 2174 Monkey Head Nebula IC 2162 Ced 72 IC 443 LBN 844 Jellyfish Nebula Sh2-249 IC 2169 Ced 78 NGC Caldwell 49 Rosette Nebula 2237,38,39,2246 LBN 943 Sh 2-280 SNR205.6- G205.5+00.5 Monoceros Nebula 00.1 NGC 2261 Caldwell 46 Hubble’s Var.
    [Show full text]
  • [CII] 158M Emission from L1630 in Orion B
    [CII] 158 µm emission from L1630 in Orion B Cornelia Pabst Leiden Observatory November 29, 2017 in collaboration with: J. R. Goicoechea, D. Teyssier, O. Bern´e,B. B. Ochsendorf, M. G. Wolfire, R. D. Higgins, D. Riquelme, C. Risacher, J. Pety, F. LePetit, E. Roueff, E. Bron, A. G. G. M. Tielens Cornelia Pabst, Leiden Observatory SOFIA tele-talk, November 29, 2017 Introduction PhD student under supervision of Xander Tielens Leiden Observatory, Netherlands Cornelia Pabst, Leiden Observatory SOFIA tele-talk, November 29, 2017 1 / 30 [CII] 158 µm emission [CII] fine-structure line one of the brightest far-infrared cooling lines of the ISM, 1% of total FIR continuum ∼ [CII] line can be observed in distant galaxies correlation of SFR and [CII] intensity: [1] for 46 nearby galaxies, [2] on Galactic scale origin of [CII] emission: dense PDRs, cold HI gas, ionized gas, CO-dark gas on Galactic scale cf. GOT C+ [2] need to spatially resolve the ISM Orion molecular cloud as template region velocity-resolved mapping allows to form a 3D picture [1] Herrera-Camus et al. (2015) ApJ 800:1, [2] Pineda et al. (2014) A&A 570:A121 Cornelia Pabst, Leiden Observatory SOFIA tele-talk, November 29, 2017 2 / 30 The optical window Image Credit: NASA/ESA/Hubble Heritage Team; M. Robberto/Hubble Space Telescope Orion Treasury Project Team Cornelia Pabst, Leiden Observatory SOFIA tele-talk, November 29, 2017 3 / 30 The infrared window Left: visible light. Right: infrared light (IRAS). Image Credit: Akira Fujii/NASA/IRAS Cornelia Pabst, Leiden Observatory SOFIA tele-talk, November 29, 2017 4 / 30 L1630 in the Orion B molecular cloud - visible Alnilam Flame Nebula (NGC 2024) Alnitak NGC 2023 σ Ori Horsehead Nebula IC 434 Image Credit: ESO, Digitized Sky Survey 2 Cornelia Pabst, Leiden Observatory SOFIA tele-talk, November 29, 2017 5 / 30 L1630 in the Orion B molecular cloud - infrared Flame Nebula (NGC 2024) NGC 2023 σ Ori Horsehead Nebula IC 434 Image Credit: NASA/JPL-Caltech (WISE) blue: 3.4 µm, cyan: 4.6 µm, green: 12 µm, red: 22 µm.
    [Show full text]
  • Orders of Magnitude (Length) - Wikipedia
    03/08/2018 Orders of magnitude (length) - Wikipedia Orders of magnitude (length) The following are examples of orders of magnitude for different lengths. Contents Overview Detailed list Subatomic Atomic to cellular Cellular to human scale Human to astronomical scale Astronomical less than 10 yoctometres 10 yoctometres 100 yoctometres 1 zeptometre 10 zeptometres 100 zeptometres 1 attometre 10 attometres 100 attometres 1 femtometre 10 femtometres 100 femtometres 1 picometre 10 picometres 100 picometres 1 nanometre 10 nanometres 100 nanometres 1 micrometre 10 micrometres 100 micrometres 1 millimetre 1 centimetre 1 decimetre Conversions Wavelengths Human-defined scales and structures Nature Astronomical 1 metre Conversions https://en.wikipedia.org/wiki/Orders_of_magnitude_(length) 1/44 03/08/2018 Orders of magnitude (length) - Wikipedia Human-defined scales and structures Sports Nature Astronomical 1 decametre Conversions Human-defined scales and structures Sports Nature Astronomical 1 hectometre Conversions Human-defined scales and structures Sports Nature Astronomical 1 kilometre Conversions Human-defined scales and structures Geographical Astronomical 10 kilometres Conversions Sports Human-defined scales and structures Geographical Astronomical 100 kilometres Conversions Human-defined scales and structures Geographical Astronomical 1 megametre Conversions Human-defined scales and structures Sports Geographical Astronomical 10 megametres Conversions Human-defined scales and structures Geographical Astronomical 100 megametres 1 gigametre
    [Show full text]
  • Sirius Astronomer Newsletter
    July 2017 Free to members, subscriptions $12 for 12 issues Volume 44, Number 7 Nebulosity from brilliant Antares shines on the lower right with rho OPH on the left. Two globular clusters are also apparent; large M4 above Antares, and NGC6144 at the 10:30 position. Image is a stack of 10 subframes, each 8 min in length, taken at the OCA Anza site on the nights of May 23rd and 24th, 2017. OCA member Rick Hull used an unmodified Canon 6D DSLR at ISO1600 through a Williams Optics 80mm FD semi-apo refractor operating at f/5.55. OCA CLUB MEETING STAR PARTIES COMING UP The free and open club meeting The Black Star Canyon site will open The next sessions of the Beginners will be held July 14 at 7:30 PM on July 15. The Anza site will be open Class will be held at the Heritage in the Irvine Lecture Hall of the on July 22. Members are encouraged Museum of Orange County at 3101 Hashinger Science Center at to check the website calendar for the West Harvard Street in Santa Ana Chapman University in Orange. latest updates on star parties and on July 7 and August 4. This month, Randy Chung and other events. Sean League of SpaceFab.US Youth SIG: contact Doug Millar will speak about private space Please check the website calendar Astro-Imagers SIG: July 1, Aug 8 telescopes, asteroid mining and for the outreach events this month! Astrophysics SIG: July 21, Aug 18 manufacturing. Volunteers are always welcome! Dark Sky Group: contact Barbara Toy NEXT MEETINGS: August 11, You are also reminded to check the September 8 (speakers TBA) web site frequently for updates to the calendar of events and other club news.
    [Show full text]
  • Sources for Icecube
    Group 3 – Wojtek, Sandy and Cheryl Neutrinos & Astrophysics question 25 Sources for IceCube A. Find a neutrino emitter Choose a TeV source from http://tevcat.uchicago.edu that could be a good neutrino emitter for the IceCube experiment at the South Pole – and say why. Choosing a source ● Supernova remnant, pulsar wind nebula, or gamma ray burst source ● Good sources of accelerated neutrinos ● High energy neutrinos (> 1TeV) ● Little atmospheric background at those energies ● High energy gamma → high energy neutrinos ● High flux (around 0.5 Crab or more) ● Or will be swamped by background ● In northern hemisphere (approx 0-60°N) ● Earth filters background, but core degrades signal Candidate 1: Crab Nebula ● Supernova remnant ● High flux - 1 Crab ● In northern hemisphere (dec = 22°) BUT... ● Lower energy neutrinos (700 GeV) Candidate 1: Crab Nebula ● Supernova remnant ● High flux - 1 Crab ● In northern hemisphere (dec = 22°) BUT... ● Lower energy (700 GeV) Candidate 2: Vela Jr ● Supernova remnant ● High flux - 1 Crab ● High energy (1TeV) BUT... ● In southern hemisphere (dec = 132°) Candidate 2: Vela Jr ● Supernova remnant ● High flux - 1 Crab ● High energy (1TeV) BUT... ● In southern hemisphere (dec = 132°) Candidate 3: Boomerang Nebula ● Supernova remnant / Pulsar Wind Nebula ● High flux - 0.44 Crabs ● High energy (35TeV) ● In northern hemisphere (dec = 61°) Candidate 3: Boomerang Nebula ● Supernova remnant / Pulsar Wind Nebula ● High flux - 0.44 Crabs ● High energy neutrinos (35TeV) ● In northern hemisphere (dec = 61°) The Boomerang –
    [Show full text]
  • 2003 Astronomy Magazine Index
    2003 astronomy magazine index Catchall (Martian crater), 11:30 observing Mars from, 7:32 hydrogen, 10:28 Subject index CCD (charge-coupled device) cameras, planets like, 6:48–53 Hydrus (constellation), 10:72–75 3:84–87, 5:84–87 seasons of, 3:72–73 A CCD techniques, 9:100–105 tilt of axis, 2:68, 5:72–73 I accidents, space-related, 7:42–47 Celestron C6-R (refractor), 11:84 EarthExplorer web site, 4:30 Achernar (star), 10:30 iceball, found beyond Pluto, 1:24 Celestron C8-N (reflector), 11:86 eclipses India, plans to visit Moon, 10:29 Advanced Camera for Surveys, 4:28 Celestron CGE-1100 (amateur telescope), in Australia (2003), 4:80–83 ALMA (Atacama Large Millimeter Array), infrared survey, 8:31 11:88 lunar integrating wavelengths, 4:24 3:36 Celestron NexStar 8 GPS (amateur telescope), of 2003, 5:18 Amalthea (Jupiter’s moon), 4:28 interferometry 1:84–87 of May 15, 2003, 5:60, 80–83, 88–89 techniques for, 7:48–53 Amateur Achievement Award, 9:32 Celestron NexStar 8i (amateur telescope), solar Andromeda Galaxy VLT interferometer, 2:32 11:89 of May 31, 2003, 5:80–83, 88–89 International Space Station, 3:31 picture of, 2:12–13 Centaurus A (NGC 5128) galaxy Edgar Wilson Award, 11:30 young stars in, 9:86–89 Internet, virtual observatories on, 9:80–85 1,000 Mira stars discovered in, 10:28 Egg Nebula, 8:36 Intes MK67 (amateur telescope), 11:89 Annefrank (asteroid), 2:32 picture of, 10:12–13 elliptical galaxies, 8:31 antineutrinos, 4:26 Io (Jupiter’s moon), 3:30 ripped apart satellite galaxy, 2:32 Eta Carinae (nebula), 5:29 ISAAC multi-mode instrument, 4:32 antisolar point, 10:18 Centaurus (constellation), 4:74–77 ETX-90EC (amateur telescope), 11:89 Antlia (constellation), 4:74–77 cepheid variable stars, 9:90–91 Europa (Jupiter’s moon), 12:30, 77 aphelion, 6:68–69 Challenger (space shuttle), 7:42–47 exoplanet magnetosphere, 11:28 J Apollo 1 (spacecraft), 7:42–47 J002E3 satellite, 1:30 Chamaeleon (constellation), 12:80–83 extrasolar planets.
    [Show full text]
  • Rosette Gazette
    The Rosette Gazette Volume 27,, IssueIssue 01 Newsletter of the Rose City Astronomers January, 2014 Discovering Astronomy through DSLR Photography Ben Canales The surge of DSLR photography has brought a unique opportunity to the world of astronomy. Ben Canales will speak about the ability of this growing night photography interest to connect newcomers to the expansive world of traditional astronomy. Ben will also share photos and timelapse videos of our night skies above the landscapes of our Pacific Northwest. Ben would like to end the talk with a short "workshop" on the settings and details of using a DSLR for star shots to be a "go forth" moment for anyone interested in trying it out. In This Issue: 1….General Meeting 2….Message From The President 3….Special Interest Groups 4….Club Contacts 5.....The Observers Corner 9….An Image and Reality 11...Planck: Revising the Based out of Portland, also be featured in an Universe Oregon, Ben Canales' night upcoming show in OMSI's 12...GOES-R and the photography of the stars has Kendall Planetarium. Ben Advanced Baseline been featured on OPB's specializes in landscape Imager Oregon Field Guide, NASA's photography at night, under the 13...2014 Star Party Astronomy Picture of the Day, stars. His style pulls back the Calendar National Geographic Travel focus from traditional deep 14...Calendars Photo of the Year, and is a space astronomy, instead winner of the contest The showcasing the expansive night World At Night. Additionally, Ben's work will sky from a human eye perspective. His website: www.theStarTrail.com Facebook: www.Facebook.com/thestartrail Everyone Welcome! Monday January 16th New Members Meeting Begins: 6:30 pm.
    [Show full text]
  • The Interstellar Medium by Nimisha G. Kantharia
    The Interstellar Medium Nimisha G. Kantharia National Centre for Radio Astrophysics RAWSC, 20 December 2012 What is ISM? ● Medium between stars – similar to our atmosphere – elements like H, O, N, S...; molecules like CO, CS, NH_3, H_2O,.....; dust.... ● Also objects like supernova remnants, planetary nebula, star forming regions, reflection nebulae....are ISM. ● Too faint for eyes to detect emission from ISM. ● Telescopes operating at wavebands ranging from gamma-ray to radio can detect emission from ISM. ● Multiwavelength all sky surveys of the Milky Way and other galaxies help us understand the composition, distribution, morphology and physical conditions in these amazing systems. RAWSC, 20 December 2012 RAWSC, 20 December 2012 Multiwavelength Milky Way RAWSC, 20 December 2012 408 MHz radio continuum: Diagnostics Synchrotron emission: relativistic Gamma rays: particles spiral in magnetic field giving rise to emission over wide Photons > 100 MeV – collisions of frequency range cosmic rays with nuclei in IS clouds + compact sources such pulsars; other sources are AGN, GRB... Mid and Far infrared emission: Emission from hot dust heated by star forming regions in the galaxy. 21cm narrow band emission: Long-lived hyperfine structure bound- bound transition in atomic hydrogen. RAWSC, 20 December 2012 Distribution of ionized gas RAWSC, 20 December 2012 Milky Way in the near infrared Disk and Bulge Disk galaxies Spiral arms not seen NIR – stars Artist's impression of the top view of our galaxy RAWSC, 20 December 2012 Discovery of ISM ● 1904 – Johannes Hartmann ● Stationary CaII lines (3934 Angstroms) in the absorption spectrum of a spectroscopic binary stellar system, Delta Orionis ● Rest of the lines Doppler shift with orbital motion.
    [Show full text]
  • ALMA Reveals Ghostly Shape of 'Coldest Place in the Universe' 24 October 2013
    ALMA reveals ghostly shape of 'coldest place in the universe' 24 October 2013 determine its true shape, which has an eerily ghost- like appearance. As originally observed with ground-based telescopes, this nebula appeared lopsided, which is how it got its name. Later observations with the Hubble Space Telescope revealed a bow-tie-like structure. The new ALMA data, however, reveal that the Hubble image tells only part of the story, and the twin lobes seen in that image may actually be a trick of the light as seen at visible wavelengths. "This ultra-cold object is extremely intriguing and we're learning much more about its true nature with ALMA," said Raghvendra Sahai, a researcher and principal scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, and lead author of a paper published in the Astrophysical Journal. "What seemed like a double lobe, or 'boomerang' shape, from Earth-based optical telescopes, is The Boomerang Nebula, called the "coldest place in the actually a much broader structure that is expanding Universe," reveals its true shape with ALMA. The rapidly into space." background blue structure, as seen in visible light with the Hubble Space Telescope, shows a classic double- The Boomerang Nebula, located about 5,000 light- lobe shape with a very narrow central region. ALMA's years away in the constellation Centaurus, is a resolution and ability to see the cold molecular gas relatively young example of an object known as a reveals the nebula's more elongated shape, as seen in red. Credit: Bill Saxton; NRAO/AUI/NSF; NASA/Hubble; planetary nebula.
    [Show full text]