Two Rings but No Fellowship: Lotr 1 and Its Relation to Planetary Nebulae
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GALEX Helix Nebula Poster
National Aeronautics and Space Administration The Helix Nebula: What is it? The object shown on the front of this poster is the This “Mountains Helix Nebula. Although this object and others like it are of Creation” image called planetary nebulae (pronounced NEB-u-lee), they was captured by really have nothing to do with planets. They got their name the Spitzer Space ZKHQDVWURQRPHUV¿rst saw them through early telescopes, Telescope in infrared because they looked similar to planets with rings around light. It reveals them, like Saturn. billowing mountains of dust ablaze with A planetary nebula is the ¿res of active star really a shell of glowing gas formation. GALEX and plasma from a star at the can see the new stars end of its life. The star has forming, because they glow brightly in ultraviolet (UV) light. blown off much of its material However, the surrounding dust and gas clouds are cooler and and what is left is a very not so visible to GALEX. compact object called a white dwarf. For a while, the white dwarf is still hot and bright A Tug of War enough to make the material Planetary nebula JnEr1, A star is an amazing from the former star glow, as seen by GALEX. ! Ow! If not for balancing act between two ! * * gravity, my head and that is what we see as a * * would explode! beautiful nebula. Over 10,000 huge forces. On the one * years or so, the gas will drift away and the white dwarf will hand, the crushing force of the star’s own gravity Gravity Heat cool so much that we can no longer see the nebula. -
Poster Abstracts
Aimée Hall • Institute of Astronomy, Cambridge, UK 1 Neptunes in the Noise: Improved Precision in Exoplanet Transit Detection SuperWASP is an established, highly successful ground-based survey that has already discovered over 80 exoplanets around bright stars. It is only with wide-field surveys such as this that we can find planets around the brightest stars, which are best suited for advancing our knowledge of exoplanetary atmospheres. However, complex instrumental systematics have so far limited SuperWASP to primarily finding hot Jupiters around stars fainter than 10th magnitude. By quantifying and accounting for these systematics up front, rather than in the post- processing stage, the photometric noise can be significantly reduced. In this paper, we present our methods and discuss preliminary results from our re-analysis. We show that the improved processing will enable us to find smaller planets around even brighter stars than was previously possible in the SuperWASP data. Such planets could prove invaluable to the community as they would potentially become ideal targets for the studies of exoplanet atmospheres. Alan Jackson • Arizona State University, USA 2 Stop Hitting Yourself: Did Most Terrestrial Impactors Originate from the Terrestrial Planets? Although the asteroid belt is the main source of impactors in the inner solar system today, it contains only 0.0006 Earth mass, or 0.05 Lunar mass. While the asteroid belt would have been much more massive when it formed, it is unlikely to have had greater than 0.5 Lunar mass since the formation of Jupiter and the dissipation of the solar nebula. By comparison, giant impacts onto the terrestrial planets typically release debris equal to several per cent of the planet’s mass. -
September 2020 BRAS Newsletter
A Neowise Comet 2020, photo by Ralf Rohner of Skypointer Photography Monthly Meeting September 14th at 7:00 PM, via Jitsi (Monthly meetings are on 2nd Mondays at Highland Road Park Observatory, temporarily during quarantine at meet.jit.si/BRASMeets). GUEST SPEAKER: NASA Michoud Assembly Facility Director, Robert Champion What's In This Issue? President’s Message Secretary's Summary Business Meeting Minutes Outreach Report Asteroid and Comet News Light Pollution Committee Report Globe at Night Member’s Corner –My Quest For A Dark Place, by Chris Carlton Astro-Photos by BRAS Members Messages from the HRPO REMOTE DISCUSSION Solar Viewing Plus Night Mercurian Elongation Spooky Sensation Great Martian Opposition Observing Notes: Aquila – The Eagle Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 27 September 2020 President’s Message Welcome to September. You may have noticed that this newsletter is showing up a little bit later than usual, and it’s for good reason: release of the newsletter will now happen after the monthly business meeting so that we can have a chance to keep everybody up to date on the latest information. Sometimes, this will mean the newsletter shows up a couple of days late. But, the upshot is that you’ll now be able to see what we discussed at the recent business meeting and have time to digest it before our general meeting in case you want to give some feedback. Now that we’re on the new format, business meetings (and the oft neglected Light Pollution Committee Meeting), are going to start being open to all members of the club again by simply joining up in the respective chat rooms the Wednesday before the first Monday of the month—which I encourage people to do, especially if you have some ideas you want to see the club put into action. -
2012 Annual Progress Report and 2013 Program Plan of the Gemini Observatory
2012 Annual Progress Report and 2013 Program Plan of the Gemini Observatory Association of Universities for Research in Astronomy, Inc. Table of Contents 0 Executive Summary ....................................................................................... 1 1 Introduction and Overview .............................................................................. 5 2 Science Highlights ........................................................................................... 6 2.1 Highest Resolution Optical Images of Pluto from the Ground ...................... 6 2.2 Dynamical Measurements of Extremely Massive Black Holes ...................... 6 2.3 The Best Standard Candle for Cosmology ...................................................... 7 2.4 Beginning to Solve the Cooling Flow Problem ............................................... 8 2.5 A Disappearing Dusty Disk .............................................................................. 9 2.6 Gas Morphology and Kinematics of Sub-Millimeter Galaxies........................ 9 2.7 No Intermediate-Mass Black Hole at the Center of M71 ............................... 10 3 Operations ...................................................................................................... 11 3.1 Gemini Publications and User Relationships ............................................... 11 3.2 Science Operations ........................................................................................ 12 3.2.1 ITAC Software and Queue Filling Results .................................................. -
When Aspherical Cosmic Bubbles Betray a Difficult Marriage
When aspherical cosmic bubbles betray a difcult marriage A study of binary central stars of Planetary Nebulae Henri M.J. Boffin (ESO) Brent Miszalski, D. Frew, A. Moffat, A. Acker, J. Köppen, Q. Parker, R. Corradi, D. Jones, M. Santander-Garcia, P. Rodriguez-Gil, M. Rubio-Diez 2011年10月27日木曜日 Outline The zoo of planetary nebulae Explaining their shape and common envelope evolution The search for binary central stars Morphology affected by binarity? A barium-rich central star discovered Summary 2011年10月27日木曜日 2011年10月27日木曜日 2011年10月27日木曜日 2011年10月27日木曜日 2011年10月27日木曜日 2011年10月27日木曜日 Balick et al./NASA/HST 2011年10月27日木曜日 2011年10月27日木曜日 SN 1987A Eta Car Necklace MyCn18 Menzel 3 2011年10月27日木曜日 V. Icke 2011年10月27日木曜日 Cosmic Ant 2011年10月27日木曜日 Hourglass Nebula MyCn18 2011年10月27日木曜日 HST WFPC2 2011年10月27日木曜日 HST ACS 2011年10月27日木曜日 Causes for density contrasts? Rapid rotation and/or Magnetic fields? 2011年10月27日木曜日 Causes for density contrasts? Rapid rotation and/or Magnetic fields? • Models can reproduce some of the features when no feedback on field is introduced • But require strong fields (not detected) • Need a dynamo to keep the field (Nordhaus et al. 2007) 2011年10月27日木曜日 Causes for density contrasts? Rapid rotation and/or Magnetic fields? Models can reproduce some of the features But require strong fields, not detected Need a dynamo to keep the field 2011年10月27日木曜日 Causes for density contrasts? Rapid rotation and/or Magnetic fields? Binary star? 2011年10月27日木曜日 Causes for density contrasts? Rapid rotation and/or Magnetic fields? Binary star? jets (accretion discs) predicted (common envelope evolution; mass transfer by wind) post-AGB (pre-PNe) 2011年10月27日木曜日 Boffin & Miszalski, 2011 2011年10月27日木曜日 A binary containing 2 WDs! Boffin et al. 2011 2011年10月27日木曜日 Common envelope evolution Credit: STScI 2011年10月27日木曜日 Common envelope evolution Credit: STScI 2011年10月27日木曜日 Boffin et al. -
The Double Helix Nebula: a Magnetic Torsional Wave Propagating out of the Galactic Centre
The Double Helix Nebula: a magnetic torsional wave propagating out of the Galactic centre Mark Morris1, Keven Uchida2, and Tuan Do1 1Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-1547, USA 2Center for Radiophysics and Space Research, Cornell University, Space Sciences Building, Ithaca, NY 14853-6801 Radioastronomical studies have indicated that the magnetic field in the central few hundred parsecs of our Milky Way Galaxy has a dipolar geometry and a strength substantially larger than elsewhere in the Galaxy, with estimates ranging up to a milligauss1-6. A strong, large-scale magnetic field can affect the Galactic orbits of molecular clouds by exerting a drag on them, it can inhibit star formation, and it can guide a wind of cosmic rays away from the central region, so a characterization of the magnetic field at the Galactic center is important for understanding much of the activity there. Here, we report Spitzer Space Telescope observations of an unprecedented infrared nebula having the morphology of an intertwined double helix. This feature is located about 100 pc from the Galaxy’s dynamical centre toward positive Galactic latitude, and its axis is oriented perpendicular to the Galactic plane. The observed segment is about 25 pc in length, and contains about 1.25 full turns of each of the two continuous, helically wound strands. We interpret this feature as a torsional Alfvén wave propagating vertically away from the Galactic disk, driven by rotation of the magnetized circumnuclear gas disk. As such, it offers a new morphological probe of the Galactic center magnetic field. -
Download This Article in PDF Format
A&A 570, A131 (2014) Astronomy DOI: 10.1051/0004-6361/201424452 & c ESO 2014 Astrophysics Eyes in the sky Interactions between asymptotic giant branch star winds and the interstellar magnetic field?;?? A. J. van Marle1, N. L. J. Cox1, and L. Decin1;2 1 KU Leuven, Institute of Astronomy, Celestijnenlaan 200D, 3001 Leuven, Belgium e-mail: [email protected] 2 Universiteit van Amsterdam, Sterrenkundig Instituut Anton Pannekoek, Science Park 904, 1098 Amsterdam, The Netherlands Received 23 June 2014 / Accepted 6 August 2014 ABSTRACT Context. The extended circumstellar envelopes (CSEs) of evolved low-mass stars display a large variety of morphologies. Understanding the various mechanisms that give rise to these extended structures is important to trace their mass-loss history. Aims. Here, we aim to examine the role of the interstellar magnetic field in shaping the extended morphologies of slow dusty winds of asymptotic giant branch (AGB) stars in an effort to pin-point the origin of so-called eye shaped CSEs of three carbon-rich AGB stars. In addition, we seek to understand if this pre-planetary nebula (PN) shaping can be responsible for asymmetries observed in PNe. Methods. Hydrodynamical simulations are used to study the effect of typical interstellar magnetic fields on the free-expanding spher- ical stellar winds as they sweep up the local interstellar medium (ISM). Results. The simulations show that typical Galactic interstellar magnetic fields of 5 to 10 µG are sufficient to alter the spherical expanding shells of AGB stars to appear as the characteristic eye shape revealed by far-infrared observations. -
Ongoing Surveys for Close Binary Central Stars and Wider Implications
Planetary Nebulae: An Eye to the Future Proceedings IAU Symposium No. 283, 2011 c International Astronomical Union 2012 A. Manchado, L. Stanghellini & D. Sch¨onberner, eds. doi:10.1017/S1743921312010782 Ongoing surveys for close binary central stars and wider implications Brent Miszalski South African Astronomical Observatory and Southern African Large Telescope Foundation, PO Box 9, Observatory, 7935, South Africa email: [email protected] Abstract. Binary central stars have long been invoked to explain the vexing shapes of plane- tary nebulae (PNe) despite there being scant direct evidence to support this hypothesis. Modern large-scale surveys and improved observing strategies have allowed us to significantly boost the number of known close binary central stars and estimate at least 20% of PNe have close binary nuclei that passed through a common-envelope (CE) phase. The larger sample of post-CE neb- ulae appears to have a high proportion of bipolar nebulae, low-ionisation structures (especially in SN1987A-like rings) and polar outflows or jets. These trends are guiding our target selec- tion in ongoing multi-epoch spectroscopic and photometric surveys for new binaries. Multiple new discoveries are being uncovered that further strengthen the connection between post-CE trends and close binaries. These ongoing surveys also have wider implications for understanding CE evolution, low-ionisation structure and jet formation, spectral classification of central stars, asymptotic giant branch (AGB) nucleosynthesis and dust obscuration events in PNe. Keywords. planetary nebulae: general, binaries: general 1. Introduction The shapes of PNe are well known to demonstrate an amazing variety shapes (e.g. Sahai et al. 2011). -
Stars, Constellations, and Dsos [50 Pts]
Reach for the Stars B – KEY Bonus (+1) TRAPPIST-1 Part I: Stars, Constellations, and DSOs [50 pts] 1. Kepler’s SNR 2. Tycho’s SNR 3. M16 (Eagle Nebula) 4. Radiation pressure (wind) from young stars 5. Cas A 6. Extinction (from interstellar dust) 7. 30 Dor 8. [T10] Tarantula Nebula 9. LMC 10. Sgr A* 11. Gravitational interaction with orbiting stars (based on movement over time) 12. M42 (Orion Nebula) 13. [T8] Trapezium 14. (Charles) Messier 15. NGC 7293 (Helix Nebula) –OR– M57 (Ring Nebula) 16. TP-AGB (thermal pulse AGB) 17. Binary system –OR– stellar winds –OR– stellar rotation –OR– magnetic fields 18. Geminga 19. [T4] Jets from pulsar spin poles 20. X-ray 21. NGC 3603 22. Among the most massive & luminous stars known 23. T Tauri 24. FUors (FU Orionis stars) 25. NGC 602 26. Open cluster 27. LMC –AND– SMC 28. Irregular 29. Tidal forces –OR– gravity of MW 30. M1 (Crab Nebula) 31. PWN (pulsar wind nebula) 32. X-ray 33. M17 (Omega Nebula) 34. Omega Nebula –OR– Swan Nebula –OR– Checkmark Nebula –OR– Horseshoe Nebula 35. NGC 6618 36. Zeta Ophiuchi 37. Bow shock (from moving quickly through the ISM) 38. It “wobbles” across the sky (moves perpendicular to overall proper motion) 39. Procyon (α CMi) 40. Mizar –AND– Alcor 41. Mizar 42. Pollux (β Gem) 43. [T5] High rotational velocity 44. Altair (α Aql) –OR– Regulus (α Leo) –OR– Vega (α Lyr) 45. Polaris (α UMi) 46. Precession 47. Binary with observed Doppler shift of spectral lines 48. Beta Cephei variable (β Cep) 49. -
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 -
Astronomy Magazine 2011 Index Subject Index
Astronomy Magazine 2011 Index Subject Index A AAVSO (American Association of Variable Star Observers), 6:18, 44–47, 7:58, 10:11 Abell 35 (Sharpless 2-313) (planetary nebula), 10:70 Abell 85 (supernova remnant), 8:70 Abell 1656 (Coma galaxy cluster), 11:56 Abell 1689 (galaxy cluster), 3:23 Abell 2218 (galaxy cluster), 11:68 Abell 2744 (Pandora's Cluster) (galaxy cluster), 10:20 Abell catalog planetary nebulae, 6:50–53 Acheron Fossae (feature on Mars), 11:36 Adirondack Astronomy Retreat, 5:16 Adobe Photoshop software, 6:64 AKATSUKI orbiter, 4:19 AL (Astronomical League), 7:17, 8:50–51 albedo, 8:12 Alexhelios (moon of 216 Kleopatra), 6:18 Altair (star), 9:15 amateur astronomy change in construction of portable telescopes, 1:70–73 discovery of asteroids, 12:56–60 ten tips for, 1:68–69 American Association of Variable Star Observers (AAVSO), 6:18, 44–47, 7:58, 10:11 American Astronomical Society decadal survey recommendations, 7:16 Lancelot M. Berkeley-New York Community Trust Prize for Meritorious Work in Astronomy, 3:19 Andromeda Galaxy (M31) image of, 11:26 stellar disks, 6:19 Antarctica, astronomical research in, 10:44–48 Antennae galaxies (NGC 4038 and NGC 4039), 11:32, 56 antimatter, 8:24–29 Antu Telescope, 11:37 APM 08279+5255 (quasar), 11:18 arcminutes, 10:51 arcseconds, 10:51 Arp 147 (galaxy pair), 6:19 Arp 188 (Tadpole Galaxy), 11:30 Arp 273 (galaxy pair), 11:65 Arp 299 (NGC 3690) (galaxy pair), 10:55–57 ARTEMIS spacecraft, 11:17 asteroid belt, origin of, 8:55 asteroids See also names of specific asteroids amateur discovery of, 12:62–63 -
Modelling the Warm H2 Infrared Emission of the Helix Nebula
Mon. Not. R. Astron. Soc. 000, 1–12 (2011) Printed 17 July 2018 (MN LATEX style file v2.2) Modelling the Warm H2 Infrared Emission of the Helix Nebula Cometary Knots Isabel Aleman1,2⋆, Albert A. Zijlstra1, Mikako Matsuura3,4, Ruth Gruenwald2, and Rafael K. Kimura2 1Jodrell Bank Centre for Astrophysics, The Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK 2IAG-USP, Universidade de S˜ao Paulo, Cidade Universit´aria, Rua do Mat˜ao 1226, S˜ao Paulo, SP, 05508-090, Brazil 3Institute of Origins, Astrophysics Group, Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK 4Institute of Origins, Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT, UK Accepted 2011 May 17. Received 2011 May 16; in original form 2010 September 28 ABSTRACT Molecular hydrogen emission is commonly observed in planetary nebulae. Images taken in infrared H2 emission lines show that at least part of the molecular emission is produced inside the ionised region. In the best-studied case, the Helix nebula, the H2 emission is produced inside cometary knots (CKs), comet-shaped structures believed to be clumps of dense neutral gas embedded within the ionised gas. Most of the H2 emission of the CKs seems to be produced in a thin layer between the ionised diffuse gas and the neutral material of the knot, in a mini photodissociation region (PDR). However, PDR models published so far cannot fully explain all the characteristics of the H2 emission of the CKs.