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The Skyscraper 2009 05.Indd
THE SKYSCRAPER • MAY 2009 A Better Galaxy Guide: Part 2, Late Spring Craig Cortis Those of you who enjoyed my first field eyepieces. the brighter objects listed and use what installment on this subject (in last Many of my choices here can be you’ve got. In closing, you might find month’s issue) will, I hope, find this seen in a 4-inch telescope and some it advisable to take another look at my second part to be even better. Three are doable in 50mm or larger binocu- article in last month’s issue. The intro- constellations are covered on the lars, but in general, I’d suggest using ductory section explains why I chose accompanying list of recommended telescopes of 6-to-8 inch aperture, at to come up with these observing lists objects and two—Virgo and Coma least for the galaxies. If you don’t own and also how they are planned. I hope Berenices-feature the grandest, richest a scope of that size range, just pick-out you’ll find my notes useful for star- assortment of galaxies bright enough to be seen in small-to-medium aperture Object Type R.A. Dec. Mag. Size Burnham’s instruments of all constellations in the sky, period. This “Virgo-Coma” cluster Virgo of galaxies is so crowded with objects M61 Sp Gx 12h 21.9m +04° 28’ 9.7 6.0x5.6’ v3, p. 2089-91 that trying to “zero-in” on only the best *M84 El Gx 12h 25.1m +12° 53’ 9.2 5.1x4.3’ v3, p. -
Rediscovering Our Galaxy Edited By
IAU IAU Symposium Proceedings of the International Astronomical Union IAU Symposium No. 334 Symposium 10–14 July 2017 Astronomers are at a crucial point in our understanding of the Milky Way. Deciphering the assembly history of our galaxy requires 334 Potsdam, Germany detailed mapping of the structure, dynamics, chemical composition, and age distribution of its stellar populations. In the last decade, astrometric, spectroscopic, photometric, and asteroseismic surveys have started to unveil the inner- and 10–14 July 2017 334 Rediscovering 10–14 July 2017 outermost regions of the Milky Way. IAU Symposium 334 explores Potsdam, Germany Our Galaxy the still open questions and focusses on the concepts emerging Potsdam, Germany Rediscovering from the analysis of these large, new, and complex datasets. This volume presents a summary of these topics, including the current novel data and the challenges they already pose to modeling, Our Galaxy before Gaia end-of-mission, PLATO, and large spectroscopic surveys such as WEAVE and 4MOST are about to start. Graduate students and researchers will learn that, in this golden era of Galactic Archaeology, we are about to rediscover our galaxy. Proceedings of the International Astronomical Union Editor in Chief: Dr Piero Benvenuti This series contains the proceedings of major scientifi c meetings held by the International Astronomical Union. Each volume contains a series of articles on a topic of current interest in astronomy, giving a timely overview of research in the fi eld. With contributions by leading -
98763 Conroy 2011 Apj 741 72
Evidence Against Dark Matter Halos Surrounding the Globular Clusters Mgc1 and Ngc 2419 The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Conroy, Charlie, Abraham Loeb, and David N. Spergel. 2011. “EVIDENCE AGAINST DARK MATTER HALOS SURROUNDING THE GLOBULAR CLUSTERS MGC1 AND NGC 2419.” The Astrophysical Journal 741 (2): 72. https://doi.org/10.1088/0004-637x/741/2/72. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:41393159 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA The Astrophysical Journal, 741:72 (5pp), 2011 November 10 doi:10.1088/0004-637X/741/2/72 C 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A. EVIDENCE AGAINST DARK MATTER HALOS SURROUNDING THE GLOBULAR CLUSTERS MGC1 AND NGC 2419 Charlie Conroy1, Abraham Loeb1, and David N. Spergel2 1 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA 2 Department of Astrophysical Sciences, Princeton University, Princeton, NJ, USA Received 2011 August 3; accepted 2011 August 3; published 2011 October 18 ABSTRACT The conjecture that the ancient globular clusters (GCs) formed at the center of their own dark matter (DM) halos was first proposed by Peebles in 1984 and has recently been revived to explain the puzzling abundance patterns observed within many GCs. In this paper, we demonstrate that the outer stellar density profile of isolated GCs is very sensitive to the presence of an extended dark halo. -
Globular Clusters in the Local Group As Probes of Galaxy Assembly
This thesis has been submitted in fulfilment of the requirements for a postgraduate degree (e.g. PhD, MPhil, DClinPsychol) at the University of Edinburgh. Please note the following terms and conditions of use: • This work is protected by copyright and other intellectual property rights, which are retained by the thesis author, unless otherwise stated. • A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. • This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author. • The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author. • When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given. Globular clusters in the Local Group as probes of galaxy assembly Jovan Veljanoski Doctor of Philosophy The University of Edinburgh 13 June 2014 Lay Summary Understanding the formation and evolution of galaxies is one of the most active areas of research in astrophysics. Gradual build-up of matter by merging pre-galactic fragments is the current preferred model of constructing massive galaxies. A key prediction of this theory is that outskirts nearby galaxies should contain remnants of this assembly process in the form of fragmented stellar streams. Found in all but the smallest of galaxies, globular star clusters (GC) are excellent probes for studying properties of galaxies. Having high luminosities, they are favourable targets in the outer regions of galaxies where the associated stellar surface brightness is low. -
Making a Sky Atlas
Appendix A Making a Sky Atlas Although a number of very advanced sky atlases are now available in print, none is likely to be ideal for any given task. Published atlases will probably have too few or too many guide stars, too few or too many deep-sky objects plotted in them, wrong- size charts, etc. I found that with MegaStar I could design and make, specifically for my survey, a “just right” personalized atlas. My atlas consists of 108 charts, each about twenty square degrees in size, with guide stars down to magnitude 8.9. I used only the northernmost 78 charts, since I observed the sky only down to –35°. On the charts I plotted only the objects I wanted to observe. In addition I made enlargements of small, overcrowded areas (“quad charts”) as well as separate large-scale charts for the Virgo Galaxy Cluster, the latter with guide stars down to magnitude 11.4. I put the charts in plastic sheet protectors in a three-ring binder, taking them out and plac- ing them on my telescope mount’s clipboard as needed. To find an object I would use the 35 mm finder (except in the Virgo Cluster, where I used the 60 mm as the finder) to point the ensemble of telescopes at the indicated spot among the guide stars. If the object was not seen in the 35 mm, as it usually was not, I would then look in the larger telescopes. If the object was not immediately visible even in the primary telescope – a not uncommon occur- rence due to inexact initial pointing – I would then scan around for it. -
Binocular Universe
Binocular Universe: A Few Hairy Objects April 2014 Phil Harrington lear skies come few and far between at this time of year, at least in my neck of the C woods, so I like to take advantage of just about every one that happens along. The old saying that April showers bring May flowers is alive and well here in the northeastern U.S., as this is traditionally one of the cloudiest and wettest months of the year. Above: Spring star map from Star Watch by Phil Harrington. Asterism Above: Finder chart for this month's Binocular Universe . Chart adapted from Touring the Universe through Binoculars Atlas (TUBA), www.philharrington.net/tuba.htm One of the reasons I'm so keen to observe the April sky is the Coma Berenices Star Cluster , one of my favorite binocular targets. It’s one of those objects that does nothing through telescopes, but really comes alive through binoculars. That’s because the star cluster spans more than 7.5 degrees of sky. To find it, aim toward the center of the large, "empty" area framed by the constellations Boötes to the east, Leo to the west, and the arc of the Big Dipper's handle to the north. Scan back and forth slowly until you bump into a wedge-shaped group of stars that will likely fill the field of your binoculars. That's the Coma Star Cluster. In fact, if you are viewing from a dark site, you can see the Coma Star Cluster as a fuzzy patch of light without using any optical aid at all. -
Binocular Certificate Handbook
Irish Federation of Astronomical Societies Binocular Certificate Handbook How to see 110 extraordinary celestial sights with an ordinary pair of binoculars © John Flannery, South Dublin Astronomical Society, August 2004 No ordinary binoculars! This photograph by the author is of the delightfully whimsical frontage of the Chiat/Day advertising agency building on Main Street, Venice, California. Binocular Certificate Handbook page 1 IFAS — www.irishastronomy.org Introduction HETHER NEW to the hobby or advanced am- Wateur astronomer you probably already own Binocular Certificate Handbook a pair of a binoculars, the ideal instrument to casu- ally explore the wonders of the Universe at any time. Name _____________________________ Address _____________________________ The handbook you hold in your hands is an intro- duction to the realm far beyond the Solar System — _____________________________ what amateur astronomers call the “deep sky”. This is the abode of galaxies, nebulae, and stars in many _____________________________ guises. It is here that we set sail from Earth and are Telephone _____________________________ transported across many light years of space to the wonderful and the exotic; dense glowing clouds of E-mail _____________________________ gas where new suns are being born, star-studded sec- tions of the Milky Way, and the ghostly light of far- Observing beginner/intermediate/advanced flung galaxies — all are within the grasp of an ordi- experience (please circle one of the above) nary pair of binoculars. Equipment __________________________________ True, the fixed magnification of (most) binocu- IFAS club __________________________________ lars will not allow you get the detail provided by telescopes but their wide field of view is perfect for NOTES: Details will be treated in strictest confidence. -
The Outer Halo Globular Cluster System of M31 – II. Kinematics
Mon. Not. R. Astron. Soc. 000, 1–24 (2014) Printed 24 July 2018 (MN LaTEX style file v2.2) The outer halo globular cluster system of M31 – II. Kinematics J. Veljanoski1, A. D. Mackey2, A. M. N. Ferguson1,⋆, A. P. Huxor3, P. Cˆot´e4,⋆ M. J. Irwin5, N. R. Tanvir6, J. Pe˜narrubia1, E. J. Bernard1, M. Fardal7, N. F. Martin8,9, A. McConnachie4, G. F. Lewis10, S. C. Chapman11, R. A. Ibata8, A. Babul12 1 Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, UK 2 Research School of Astronomy & Astrophysics, Australian National University, Mt. Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611, Australia 3 Astronomisches Rechen-Institut, Zentrum f¨ur Astronomie der Universit¨at Heidelberg, M¨onchhofstraße 12-14, 69120 Heidelberg, Germany. 4 NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7, Canada 5 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK 6 Department of Physics & Astronomy, University of Leicester, Leicester LE1 7RH, UK 7 University of Massachusetts, Department of Astronomy, LGRT 619-E, 710 N. Pleasant Street, Amherst, Massachusetts, 01003-9305, USA 8 Observatoire de Strasbourg, 11, rue de l’Universit´e, F-67000 Strasbourg, France 9 Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg, Germany 10 Institute of Astronomy, School of Physics, University of Sydney, NSW 2006, Australia 11 Dalhousie University, Dept. of Physics and Atmospheric Science, Coburg Road Halifax, B3H1A6, Canada 12 Department of Physics and Astronomy, University of Victoria, Elliott Building, 3800 Finnerty Road Victoria, BC V8P 5C2 Canada 24 July 2018 ABSTRACT We present a detailed kinematic analysis of the outer halo globular cluster system of the Andromeda galaxy (M31). -
Explore the Universe Observing Program
The RASC Explore the Universe Observing Program Welcome to the RASC Explore the Universe observing program, designed to provide any observer with a well-rounded introduction to the night sky visible from the Northern Hemisphere. Following EtU is an excellent way to gain knowledge and experience in amateur astronomy. You will find that a planned observing session based on EtU results in a more satisfying and interesting experience. You will learn and improve your observing skills, an excellent preparation for more challenging observing programs such as the Messier Catalogue, The Finest NGC Objects, and the two lunar programs. Those who complete the observing program and have their observations validated will earn a certificate and pin (RASC membership not required). The program covers the full range of astronomical objects. Here is a summary: Constellations Observing and Bright Deep-Sky Objective Stars The Moon Solar System Objects Double Stars Total Requirement 12 16 5 12 10 55 Available 24 32 10 24 20 110 In each category, a range of objects is provided so that you can begin the program at any time of the year. In order to earn your certificate, you need to observe a minimum of 55 of the 110 objects available. Here is a summary of some of the terms and abbreviations used in this program: Instrument (V/B/T) V—Visual (unaided eye), B—Binocular, T—Telescope* Description A brief description of the object, its common name, and other details. Con. Constellation in which an object can be found. See www.iau.org/public/themes/constellations/. Mag. -
第 28 届国际天文学联合会大会 Programme Book
IAU XXVIII GENERAL ASSEMBLY 20-31 AUGUST, 2012 第 28 届国际天文学联合会大会 PROGRAMME BOOK 1 Table of Contents Welcome to IAU Beijing General Assembly XXVIII ........................... 4 Welcome to Beijing, welcome to China! ................................................ 6 1.IAU EXECUTIVE COMMITTEE, HOST ORGANISATIONS, PARTNERS, SPONSORS AND EXHIBITORS ................................ 8 1.1. IAU EXECUTIVE COMMITTEE ..................................................................8 1.2. IAU SECRETARIAT .........................................................................................8 1.3. HOST ORGANISATIONS ................................................................................8 1.4. NATIONAL ADVISORY COMMITTEE ........................................................9 1.5. NATIONAL ORGANISING COMMITTEE ..................................................9 1.6. LOCAL ORGANISING COMMITTEE .......................................................10 1.7. ORGANISATION SUPPORT ........................................................................ 11 1.8. PARTNERS, SPONSORS AND EXHIBITORS ........................................... 11 2.IAU XXVIII GENERAL ASSEMBLY INFORMATION ............... 14 2.1. LOCAL ORGANISING COMMITTEE OFFICE .......................................14 2.2. IAU SECRETARIAT .......................................................................................14 2.3. REGISTRATION DESK – OPENING HOURS ...........................................14 2.4. ON SITE REGISTRATION FEES AND PAYMENTS ................................14 -
Stsci Newsletter: 2017 Volume 034 Issue 02
2017 - Volume 34 - Issue 02 Emerging Technologies: Bringing the James Webb Space Telescope to the World Like the rest of the Institute, excitement is building in the Office of Public Outreach (OPO) as the clock winds down for the launch of the James Webb Space Telescope. Our task is translating and sharing this excitement over groundbreaking engineering—and the scientific discoveries to come—with the public. Webb @ STScI In the lead-up to Webb’s launch in Spring 2019, the Institute continues its work as the science and operations center for the mission. The Institute has played a critical role in a number of recent Webb mission milestones. Updates on Hubble Operation at the Institute Observations with the Hubble Space Telescope continue to be in great demand. This article discusses Cycle 24 observing programs and scheduling efficiency, maintaining COS productivity into the next decade, keeping Hubble operations smooth and efficient, and ensuring the freshness of Hubble archive data. Hubble Cycle 25 Proposal Selection Hubble is in high demand and continues to add to our understanding of the universe. The peer-review proposal selection process plays a fundamental role in establishing a merit-based science program, and that is only possible thanks to the work and integrity of all the Time Allocation Committee (TAC) and review panel members, and the external reviewers. We present here the highlights of the Cycle 25 selection process. Using Gravity to Measure the Mass of a Star In a reprise of the famous 1919 solar eclipse experiment that confirmed Einstein's general relativity, the nearby white dwarf, Stein 2051 B, passed very close to a background star in March 2014. -
Gravity: Dark Sector, Post-Newtonian Limit and Schwarzschild Solution
universe Article d Gravity: Dark Sector, Post-Newtonian Limit and Schwarzschild Solution Jorge Alfaro 1,*,† and Pablo González 2,† 1 Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Macul, Santiago 7810000, Chile 2 Sede Esmeralda, Universidad de Tarapacá, Avda. Luis Emilio Recabarren 2477, Iquique 1130000, Chile; [email protected] * Correspondence: jalfaro@fis.puc.cl † These authors contributed equally to this work. Received: 17 March 2019; Accepted: 20 April 2019; Published: 26 April 2019 Abstract: We present a new kind of model, which we call d Theories, where standard theories are modified including new fields, motivated by an additional symmetry (d symmetry). In previous works, we proved that d Theories just live at one loop, so the model in a quantum level can be interesting. In the gravitational case, we have d Gravity, based on two symmetric tensors, gmn and g˜mn, where quantum corrections can be controlled. In this paper, a review of the classical limit of d Gravity in a Cosmological level will be developed, where we explain the accelerated expansion of the universe without Dark Energy and the rotation velocity of galaxies by the Dark Matter effect. Additionally, we will introduce other phenomenon with d Gravity like the deflection of the light produced by the sun, the perihelion precession, Black Holes and the Cosmological Inflation. Keywords: modified gravity; dark energy; dark matter; general relativity 1. Introduction In the last century, the cosmological observations have revealed that the dynamic of the Universe is dominated by an accelerated expansion, apparently due to a mysterious component called Dark Energy [1–3].