DOCSLIB.ORG

The Impact of Giant Stellar Outflows on Molecular Clouds

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

The Impact of Giant Stellar Outflows on Molecular Clouds A thesis presented by H´ector G. Arce Nazario to The Department of Astronomy in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of Astronomy Harvard University Cambridge, Massachusetts October, 2001 c 2001, by H´ector G. Arce Nazario All Rights Reserved ABSTRACT Thesis Advisor: Alyssa A. Goodman Thesis by: H´ector G. Arce Nazario We use new millimeter wavelength observations to reveal the important effects that giant (parsec-scale) outflows from young stars have on their surroundings. We find that giant outflows have the potential to disrupt their host cloud, and/or drive turbulence there. In addition, our study confirms that episodicity and a time-varying ejection axis are common characteristics of giant outflows. We carried out our study by mapping, in great detail, the surrounding molecular gas and parent cloud of two giant Herbig-Haro (HH) flows; HH 300 and HH 315. Our study shows that these giant HH flows have been able to entrain large amounts of molecular gas, as the molecular outflows they have produced have masses of 4 to 7 M |which is approximately 5 to 10% of the total quiescent gas mass in their parent clouds. These outflows have injected substantial amounts of −1 momentum and kinetic energy on their parent cloud, in the order of 10 M km s and 1044 erg, respectively. We find that both molecular outflows have energies comparable to their parent clouds' turbulent and gravitationally binding energies. In addition, these outflows have been able to redistribute large amounts of their surrounding medium-density (n ∼ 103 cm−3) gas, thereby sculpting their parent cloud and affecting its density and velocity distribution at distances as large as 1 to 1.5 pc from the outflow source. Our study, in combination with other outflow studies, indicate that a single giant molecular outflow in a molecular cloud of less than about 80 M has the potential to seriously disrupt its parent cloud. We, therefore, conclude that the cumulative action of many giant outflows will certainly have a profound effect on their cloud's evolution and fate. Our detail study of the outflow morphology, velocity structure, and momentum distribution |among other properties of both outflows| lead us to suggest that they are predominantly formed by bow-shock prompt entrainment, from an episodic wind with a time-varying axis. Close to the outflow source of HH 315, though, the coexistence of a jet-like wind and a wide-angle wind explains better the observed outflow properties. iii iv Contents Abstract . iii List of Figures . ix List of Tables . xiii Acknowledgments . xv 1 Introduction 1 1.1 A brief introduction to star formation . 1 1.2 The outflow stage . 6 1.2.1 Herbig-Haro flows . 6 1.2.2 Molecular Outflows . 9 1.3 Outflow-Cloud interaction . 11 1.3.1 Outflow-cloud interaction in the immediate vicinity of the out- flow source . 12 1.3.2 Outflow-cloud interaction at parsec scales . 21 1.4 What drives molecular outflows? . 22 1.5 Brief discussion of shocks . 30 1.5.1 Properties of shocks . 30 1.5.2 Shocks with Magnetic Fields . 34 1.5.3 Bow shocks in collimated winds from young stellar objects . 35 1.6 Why this Thesis? . 36 1.7 Thesis Plan . 39 v 2 The Episodic, Precessing Giant Molecular Outflow from IRAS 04239+2436 (HH 300) 43 2.1 Introduction . 44 2.2 Observations . 47 2.2.1 12CO(2{1) Data . 47 2.2.2 12CO(1{0), 13CO(1{0), and C18O(1{0) Data . 50 2.3 Results . 51 2.3.1 13CO(1{0) Maps . 52 2.3.2 12CO Maps . 55 2.3.3 Outflow Physical Properties . 59 2.4 Discussion . 68 2.4.1 Mass and Energetics . 68 2.4.2 Mass-Velocity Relation . 71 2.4.3 The episodic and precessing nature of the flow . 76 2.4.4 Effects on the cloud . 81 2.4.5 The structure of B18w . 85 2.4.6 The cumulative effect of outflows . 87 2.5 Conclusion . 87 3 The Mass-Velocity and Position-Velocity Relations in Episodic Out- flows 91 3.1 Introduction . 92 3.2 Mass-Velocity Relation . 93 3.2.1 Observing the M − v Relation . 93 3.2.2 Modeling the M − v Relation . 94 3.2.3 The M − v Relation in Episodic Outflows . 95 3.3 Position-Velocity Relation . 98 3.3.1 Observing p(v) . 98 vi 3.3.2 Modeling p(v) . 98 3.3.3 The p(v) in Episodic Outflows . 100 3.4 Discussion and Conclusions . 101 3.4.1 Reconstructing History . 101 3.4.2 The need for new models . 101 4 The Great PV Ceph Outflow: A Case Study in Outflow-Cloud Interaction 103 4.1 Introduction . 104 4.2 Observations . 109 4.2.1 12CO(2{1) Data . 109 4.2.2 12CO(1{0), 13CO(1{0), and C18O(1{0) Data . 111 4.3 Results . 112 4.3.1 12CO(2{1) Maps . 112 4.3.2 13CO(1{0) Maps . 117 4.3.3 Dissecting the PV Ceph cloud . 120 4.3.4 The flow in context with its parent cloud's structure . 125 4.3.5 Outflow Mass . 126 4.4 Discussion . 132 4.4.1 Mass and Energetics of the Outflow . 132 4.4.2 The effects of the outflow on the ambient gas . 136 4.5 Summary and Conclusion . 147 5 Molecular bow shocks, jets and wide-angle winds: a high resolution study of the entrainment mechanism of the PV Ceph Outflow 151 5.1 Introduction . 152 5.2 Observations . 155 5.3 Results . 158 vii 5.3.1 The region surrounding HH 315B and HH 315C (hh315b+c) . 158 5.3.2 The region surrounding HH 215 and PV Ceph (hh215) . 167 5.3.3 The region surrounding HH 315E . 175 5.4 Analysis and Discussion . 176 5.4.1 Temperature distribution . 176 5.4.2 Kinematics and momentum distribution . 182 5.4.3 Bow shocks, jets, and wide-angle winds . 192 5.4.4 Episodicity and axis wandering of the HH 315 flow . 199 5.5 Summary . 204 6 A Quantitative Comparison 207 6.1 Outflow-cloud interaction . 208 6.1.1 Disruption of a cloud by a giant outflow . 208 6.1.2 Many outflows in one cloud . 218 6.1.3 Recipe for destruction . 223 6.1.4 Concluding Remarks . 224 6.2 Driving mechanism . 226 6.3 Episodicity . 231 6.4 Wandering outflow axis . 234 7 Summary and Future Work 239 7.1 Summary . 239 7.2 Future Work . 243 A Estimating Excitation Temperature Using CO Line Ratios 247 Bibliography 251 viii List of Figures 1.1 Taurus molecular cloud complex observed at three different molecular spectral lines . 3 1.2 Schematic picture of a star-forming region . 5 1.3 Image of the inner region of the HH 111 jet . 7 1.4 Map of the L1551-IRS5 molecular outflow . 10 1.5 L1228: example of core disruption by an outflow through kinematical evidence . 13 1.6 L43: example of an outflow-created core cavity revealed by the pres- ence of a reflection nebula . 14 1.7 HH 56/57 region: example of a core cavity created by an outflow, revealed as a region of lower extinction in a dark cloud . 16 1.8 Mon R2: example of an outflow-created cavity revealed through molec- ular line observations . 17 1.9 NGC 1333: example of a region where outflow-created cavities are observed in millimeter continuum emission . 18 1.10 Velocity maps of the L1228 bipolar 13CO(1{0) outflow . 20 1.11 Schematic illustration of the wide-angle wind, jet bow shock, and turbulent jet entrainment models. 24 1.12 RNO 43: Example of a bow-shock entrained molecular outflow, in- ferred from the outflow kinematics and morphology . 28 1.13 L1157: Example of a bow-shock entrained molecular outflow, inferred from the outflow chemistry and morphology . 29 1.14 Schematics of a plane-parallel shock . 31 ix 1.15 Schematic illustration of the behavior of shocked gas . 32 1.16 Schematic illustration a bow shock . 35 1.17 Cartoon figure of the on-the-fly mapping technique . 38 1.18 Schematic representation of thesis observations . 40 2.1 13CO(1{0) integrated intensity map of the B18 cloud . 46 2.2 Average spectra of mapped region in B18w . 49 2.3 13CO(1{0) velocity maps of the B18w region . 53 2.4 Velocity maps of the 12CO(2{1) HH 300 molecular outflow . 56 2.5 Velocity maps of the 12CO(1{0) HH 300 molecular outflow . 57 2.6 12CO(1{0) integrated intensity map of HH 300 overlaid on optical image of the region . 57 2.7 Velocity-dependent opacity correction of 12CO(1{0) line in the HH 300 molecular outflow . 63 2.8 Momentum map of the HH 300 molecular outflow . ..
Recommended publications
  • 145, September 2010

    145, September 2010

    British Astronomical Association VARIABLE STAR SECTION CIRCULAR No 145, September 2010 Contents EG Andromedae Light Curve ................................................... inside front cover From the Director ............................................................................................... 1 Letter Page. Visual Observing ............................................................................ 4 Epsilon Aurigae Spectroscopically at Mid Eclipse .......................................... 5 Eclipsing Binary News ...................................................................................... 7 AO Cassiopeiae Phase Diagram ............................................................ 9 PV Cephei and Gyulbudaghian’s Nebula ........................................................ 10 WR140 Periastron Campaign Update .............................................................. 12 VSS Meeting, Pendrell Hall. The Central Stars of Planetary Nebulae ............ 14 RR Coronae Borealis 1993-2004 ...................................................................... 16 TU Cassiopeiae Phase Diagram 2005-2010 ..................................................... 18 Binocular Priority List ..................................................................................... 19 Eclipsing Binary Predictions ............................................................................ 20 Charges for Section Publications .............................................. inside back cover Guidelines for Contributing to the Circular .............................
  • Academic Reading in Science Copyright 2014 © Chris Elvin Copyright Notice

    Academic Reading in Science Copyright 2014 © Chris Elvin Copyright Notice

    Academic Reading in Science Copyright 2014 © Chris Elvin Copyright Notice Academic Reading in Science contains adaptations of Wikipedia copyrighted material. All pages containing these adaptations can be identified by the logo below; This logo is visible at the foot of every page in which Wikipedia articles have been adapted. Furthermore, all adaptations of Wikipedia sources show a URL at the foot of the article which you may use to access the original article. Pages which do not show the logo above are the copyright of the author Chris Elvin, and may not be used without permission. Creative Commons Deed You are free: to Share—to copy, distribute and transmit the work, and to Remix—to adapt the work Under the following conditions: Attribution—You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work.) Share Alike—If you alter, transform, or build upon this work, you may distribute the resulting work only under the same, similar or a compatible license. With the understanding that: Waiver—Any of the above conditions can be waived if you get permission from the copyright holder. Other Rights—In no way are any of the following rights affected by the license: your fair dealing or fair use rights; the author’s moral rights; and rights other persons may have either in the work itself or in how the work is used, such as publicity or privacy rights. Notice—For any reuse or distribution, you must make clear to others the license terms of this work.
  • Alyssa Goodman, Naomi Ridge, Scott Wolk, Scott Schnee, Di Li & Bryan

    Alyssa Goodman, Naomi Ridge, Scott Wolk, Scott Schnee, Di Li & Bryan

    COMPLET(E)ING THE STAR-FORMATION HISTORY OF THE RHO-OPH REGION Alyssa Goodman, Naomi Ridge, Scott Wolk, Scott Schnee, Di Li & Bryan Gaensler Background The interaction of newly formed stars with their parent cloud, particularly in the case of massive stars, can have significant consequences for the subsequent development of the cloud. Hot, massive stars will cause cloud disruption through their ionizing flux as well as through the momentum in their stellar winds. Alternatively, given the right conditions in the cloud, stellar winds may also cause the collapse of cloud cores and induce further star formation. Located only 160pc from the Sun, the Ophiuchus molecular cloud is one of the most conspicuous nearby regions where low- and intermediate-mass star formation is taking place (e.g. Wilking 1992 for a review). The Ophiuchus cloud consists of two massive, centrally condensed cores, L1688 and L1689, from each of which a filamentary system of streamers extends to the north-east over tens of parsecs (e.g. Loren 1989). While little star formation activity is observed in the streamers, the westernmost core, L1688 (figure 1), harbors a rich cluster of young stellar objects (YSOs) at various evolutionary stages and is distinguished by a high star-formation efficiency (Wilking & Lada 1983 - hereafter WL83). This young stellar cluster and the cloud core in which it resides are commonly referred to as the ρ-Oph star-forming region. Both the gas/dust content and the embedded stellar population of ρ−Oph have been extensively studied for more than two decades. The distribution of the low-density molecular gas was mapped in C18O(1-0) by WL83, revealing a ridge of high column density gas.
  • Winter Constellations

    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.
  • Aerodynamic Phenomena in Stellar Atmospheres, a Bibliography

    Aerodynamic Phenomena in Stellar Atmospheres, a Bibliography

    - PB 151389 knical rlote 91c. 30 Moulder laboratories AERODYNAMIC PHENOMENA STELLAR ATMOSPHERES -A BIBLIOGRAPHY U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS ^M THE NATIONAL BUREAU OF STANDARDS Functions and Activities The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; in- vention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover. Publications The results of the Bureau's work take the form of either actual equipment and devices or pub- lished papers.
  • Metallicities of the Β Cephei Stars from Low-Resolution Ultraviolet Spectra

    Metallicities of the Β Cephei Stars from Low-Resolution Ultraviolet Spectra

    A&A 433, 659–669 (2005) Astronomy DOI: 10.1051/0004-6361:20040396 & c ESO 2005 Astrophysics Metallicities of the β Cephei stars from low-resolution ultraviolet spectra E. Niemczura and J. Daszynska-Daszkiewicz´ Astronomical Institute, Wrocław University, ul. Kopernika 11, 51-622 Wrocław, Poland e-mail: [email protected] Received 5 March 2004 / Accepted 22 November 2004 Abstract. We derive basic stellar parameters (angular diameters, effective temperatures, metallicities) and interstellar reddening for all β Cephei stars observed during the IUE satellite mission, including those belonging to three open clusters. The parameters are derived by means of an algorithmic procedure of fitting theoretical flux distributions to the low-resolution IUE spectra and ground-based spectrophotometric observations. Since the metallicity has a special importance for pulsating B-type stars, we focus our attention in particular on this parameter. Key words. stars: early-type – stars: abundances – stars: variables: general 1. Introduction In this paper we analyze the IUE (International Ultraviolet Explorer) data combined with ground-based spectrophotomet- β Cephei variables are a well-known group of early B-type ric observations of β Cephei stars. The ultraviolet (UV) part pulsating stars. Their pulsations are driven by the classical of the spectra of main-sequence B-type stars is very rich in κ-mechanism, operating in the layer of the metal opacity bump lines of the iron-group elements. Because the greatest amount ≈ × 5 at T 2 10 K caused by the large number of absorption of energy for these objects is emitted in the spectral region be- lines of the iron-group elements.
  • Successful Observing Sessions HOWL-EEN FUN Kepler’S Supernova Remnant Harvard’S Plate Project and Women Computers

    Successful Observing Sessions HOWL-EEN FUN Kepler’S Supernova Remnant Harvard’S Plate Project and Women Computers

    Published by the Astronomical League Vol. 69, No. 4 September 2017 Successful Observing Sessions HOWL-EEN FUN Kepler’s Supernova Remnant Harvard’s Plate Project and Women Computers T HE ASTRONOMICAL LEAGUE 1 he 1,396th entry in John the way to HR 8281, is the Dreyer’s Index Catalogue of Elephant’s Trunk Nebula. The T Nebulae and Clusters of left (east) edge of the trunk Stars is associated with a DEEP-SKY OBJECTS contains bright, hot, young galactic star cluster contained stars, emission nebulae, within a large region of faint reflection nebulae, and dark nebulosity, and a smaller region THE ELEPHANT’S TRUNK NEBULA nebulae worth exploring with an within it called the Elephant’s 8-inch or larger telescope. Trunk Nebula. In general, this By Dr. James R. Dire, Kauai Educational Association for Science & Astronomy Other features that are an entire region is absolute must to referred to by the check out in IC pachyderm 1396 are the proboscis phrase. many dark IC 1396 resides nebulae. Probably in the constellation the best is Cepheus and is Barnard 161. This located 2,400 light- dark nebula is years from Earth. located 15 To find IC 1396, arcminutes north start at Alpha of SAO 33652. Cephei, a.k.a. The nebula Alderamin, and go measures 5 by 2.5 five degrees arcminutes in southeast to the size. The nebula is fourth-magnitude very dark. Myriad red star Mu Cephei. Milky Way stars Mu Cephei goes by surround the the Arabic name nebula, but none Erakis. It is also can be seen in called Herschel’s this small patch of Garnet Star, after the sky.
  • Wynyard Planetarium & Observatory a Autumn Observing Notes

    Wynyard Planetarium & Observatory a Autumn Observing Notes

    Wynyard Planetarium & Observatory A Autumn Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn Tour of the Sky with the Naked Eye CASSIOPEIA Look for the ‘W’ 4 shape 3 Polaris URSA MINOR Notice how the constellations swing around Polaris during the night Pherkad Kochab Is Kochab orange compared 2 to Polaris? Pointers Is Dubhe Dubhe yellowish compared to Merak? 1 Merak THE PLOUGH Figure 1: Sketch of the northern sky in autumn. © Rob Peeling, CaDAS, 2007 version 1.2 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. Close to the horizon is a group of stars like the outline of a saucepan with the handle stretching to your left. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The two right-hand stars are called the Pointers. Can you tell that the higher of the two, Dubhe is slightly yellowish compared to the lower, Merak? Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white- hot. 2. Use the Pointers to guide you upwards to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the left are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris.
  • STELLA Nummer 3 1992

    STELLA Nummer 3 1992

    _ *S*T*E*L*L*A* är medlemstidningen UTGIVEN av och för STAR, Stockholms amatörastro- nomer. Tidningen UTKOMMER med ca 300 ex. 4 GGR/ÅR och erhålles gratis av medlemmar. i REDAKTÖRER och ansvariga utgivare är Hans Hellberg Jens Ergon Lofotengatan 16, Husby Kaggeholmsvägen 66 164 33 KISTA 122 40 ENSKEDE i ALLA BIDRAG AR VÄLKOMNA. men de skall helst vara utskrivna på elskrivmaskin, skön- eller laserskrivare. Red förbehåller sig att taga bort i eller redigera artiklar så att de passar det aktuella numret i samråd med förf. Ar du tveksam om materialet passar. ring och hör med red. Tala om hur du vill ha din artikel. ~k MEDLEM i STAR blir man genom att betala in ársavgiften till STAR'S postgiro 70 87 05 - 9. För l992 gäller följande avgifter: 75:- för dem som är under 26 är, 100:- för övriga. För ytterligare l00:- kan man även bli medlem av Svenska Astronomiska sällskapet och fà Astronomisk Tidsskrift. Detta förmånliga erbjudande gäller endast för STARmedlemmar, som betalar avgiften till STAR'S postgiro. Glöm ej att ange namm adress, samt om du är ny medlem. Å' STAR bildades 1988 och är en sammanslagning av tidigare astronomi- föreningar i Stockholm. STAR förfogar över tre OBSERVATORIER i Stockholmstrakten; i Djursholm. i Saltsjöbaden och i vàr KLUBBLOKAL, MAGNETHUSET på Observatoriekullen. STAR anordnar föredrag, bild: och filmvisningar. astronomiska observationer, astrofoto, teleskopbygge, vanlig mötesverksamhet m m. Pâ måndagar håller STAR, utom under helg eller lov, ÖPPET HUS i Magnethuset. på Observatoriekullen. kl l9,00. Har du frågor? Kom till oss eller skriv, via KLUBBENS ADRESS: STAR _ Gamla Observatoriet Drottning atan 120 113 60 OCKHOLM Ordförande; Mikael Jargelius Teknisk redaktör; Hans Hellberg Grafikv.
  • Nebula in NGC 2264

    Nebula in NGC 2264

    Durham E-Theses The polarisation of the cone(IRN) Nebula in NGC 2264 Hill, Marianne C.M. How to cite: Hill, Marianne C.M. (1991) The polarisation of the cone(IRN) Nebula in NGC 2264, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/6098/ 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 THE POLARISATION OF THE CONE(IRN) NEBULA IN NGC 2264 MARIANNE C. M. HILL A Thesis submitted to the University of Durham for the degree of Master of Science. The copyright of this thesis rests with the author. No quotation from it should be published without prior consent and information derived from it should be acknowledged. Department of Physics. September 1991 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.
  • Astronomy 2008 Index

    Astronomy 2008 Index

    Astronomy Magazine Article Title Index 10 rising stars of astronomy, 8:60–8:63 1.5 million galaxies revealed, 3:41–3:43 185 million years before the dinosaurs’ demise, did an asteroid nearly end life on Earth?, 4:34–4:39 A Aligned aurorae, 8:27 All about the Veil Nebula, 6:56–6:61 Amateur astronomy’s greatest generation, 8:68–8:71 Amateurs see fireballs from U.S. satellite kill, 7:24 Another Earth, 6:13 Another super-Earth discovered, 9:21 Antares gang, The, 7:18 Antimatter traced, 5:23 Are big-planet systems uncommon?, 10:23 Are super-sized Earths the new frontier?, 11:26–11:31 Are these space rocks from Mercury?, 11:32–11:37 Are we done yet?, 4:14 Are we looking for life in the right places?, 7:28–7:33 Ask the aliens, 3:12 Asteroid sleuths find the dino killer, 1:20 Astro-humiliation, 10:14 Astroimaging over ancient Greece, 12:64–12:69 Astronaut rescue rocket revs up, 11:22 Astronomers spy a giant particle accelerator in the sky, 5:21 Astronomers unearth a star’s death secrets, 10:18 Astronomers witness alien star flip-out, 6:27 Astronomy magazine’s first 35 years, 8:supplement Astronomy’s guide to Go-to telescopes, 10:supplement Auroral storm trigger confirmed, 11:18 B Backstage at Astronomy, 8:76–8:82 Basking in the Sun, 5:16 Biggest planet’s 5 deepest mysteries, The, 1:38–1:43 Binary pulsar test affirms relativity, 10:21 Binocular Telescope snaps first image, 6:21 Black hole sets a record, 2:20 Black holes wind up galaxy arms, 9:19 Brightest starburst galaxy discovered, 12:23 C Calling all space probes, 10:64–10:65 Calling on Cassiopeia, 11:76 Canada to launch new asteroid hunter, 11:19 Canada’s handy robot, 1:24 Cannibal next door, The, 3:38 Capture images of our local star, 4:66–4:67 Cassini confirms Titan lakes, 12:27 Cassini scopes Saturn’s two-toned moon, 1:25 Cassini “tastes” Enceladus’ plumes, 7:26 Cepheus’ fall delights, 10:85 Choose the dome that’s right for you, 5:70–5:71 Clearing the air about seeing vs.
  • Spaziergang Unter Sternen“ – Im Tübinger Ferienprogramm 2012 Ausgerichtet Von Der Astronomischen Vereinigung Tübingen E.V

    Spaziergang Unter Sternen“ – Im Tübinger Ferienprogramm 2012 Ausgerichtet Von Der Astronomischen Vereinigung Tübingen E.V

    „Spaziergang unter Sternen“ – im Tübinger Ferienprogramm 2012 Ausgerichtet von der Astronomischen Vereinigung Tübingen e.V. = AVT (www.sternwarte-tuebingen.de); Wolfgang Martin Wettlaufer Der Sternenhimmel – in der freien Natur ist der nur zu erkennen unter einem dunklen Firmament. Weil die Sterne so unglaublich weit in der Ferne stehen, erscheinen sie uns nur als feine Lichtpunkte. Trotzdem sind sie gewaltige Himmelskörper wie ‚unser‘ Stern: die Sonne, und deshalb vermögen sie so blendend zu leuchten wie sie. Wie groß, wie hell und wie fern uns die Gestirne sind, das zu erkennen haben Astronomen lange forschen müssen! Wir wollen ein wenig über sie erfahren, während wir mit bloßen Augen und mit Ferngläsern zu ihnen aufblicken (abschließend noch mit den großen Teleskopen der Sternwarte). Auch ein paar von den 88 Sternbildern, die es am Himmel gibt, werden wir kennenlernen; oft bilden weniger helle Sterne ihre Umrisse. Deshalb wählen wir uns für einen tieferen Blick auf dieses große „Naturschauspiel“ auch einen mondlosen Abend, und dazu einen Ort, der möglichst weitab vom Streulicht der vielen Lampen gelegen ist. An den Anfang stellen wir nun ein wenig bekanntes Sternbild, das sich im Spätsommer und Herbst aber gut beobachten läßt; es steht abends im Norden hoch am Himmel: CEPHEUS. Benannt nach einem König aus der antiken griechischen Sagenwelt (die Nachbar-Sternbilder Cassiopeia = das „Himmels-W“, und Andromeda gehören auch dazu), zeigt es uns einige „bunte“ Sterne – rötlich oder blau sind sie gefärbt, was uns richtig erst im Fernglas oder Fernrohr auffällt! Hier der CEPHEUS über der Sternwartenkuppel: Nördlicher α Cephei = Alderamin Beta Cephei Himmelspol +Polarstern Größter Riesenstern: VV Cephei (Doppel) µ Cephei: Granatstern 2002: Komet Ikeya-Zhang Zeta Cephei Gamma Cephei Jota Cephei Delta Cephei Tübinger Sternwarte, 8,2-m-Kuppel (von 1956) Abb.