Stsci Newsletter: 1997 Volume 014 Issue 01
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On the Weak-Wind Problem in Massive Stars: X-Ray Spectra Reveal a Massive Hot Wind in Mu Columbae
East Tennessee State University From the SelectedWorks of Richard Ignace September 10, 2012 On the Weak-Wind Problem in Massive Stars: X- Ray Spectra Reveal a Massive Hot Wind in mu Columbae. David P. Huenemoerder, Massachusetts nI stitute of Technology Lidia M. Oskinova, University of Potsdam Richard Ignace, East Tennessee State University Wayne L. Waldron, Eureka Scientific nI c. Helge Todt, University of Potsdam, et al. Available at: https://works.bepress.com/richard_ignace/61/ The Astrophysical Journal Letters, 756:L34 (5pp), 2012 September 10 doi:10.1088/2041-8205/756/2/L34 C 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A. ON THE WEAK-WIND PROBLEM IN MASSIVE STARS: X-RAY SPECTRA REVEAL A MASSIVE HOT WIND IN μ COLUMBAE David P. Huenemoerder1, Lidia M. Oskinova2, Richard Ignace3, Wayne L. Waldron4, Helge Todt2, Kenji Hamaguchi5,6, and Shunji Kitamoto7 1 Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar Street, Cambridge, MA 02139, USA 2 Institute for Physics and Astronomy, University of Potsdam, D-14476 Potsdam, Germany 3 Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614, USA 4 Eureka Scientific Inc., 2452 Dellmer Street, Suite 100, Oakland, CA 94602, USA 5 CRESST and X-ray Astrophysics Laboratory, NASA/GSFC, Greenbelt, MD 20771, USA 6 Department of Physics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA 7 Department of Physics, Rikkyo University, Tokyo 171-8501, Japan Received 2012 June 16; accepted 2012 August 3; published 2012 August 22 ABSTRACT μ Columbae is a prototypical weak-wind O star for which we have obtained a high-resolution X-ray spectrum with the Chandra LETG/ACIS instrument and a low-resolution spectrum with Suzaku. -
Near and Mid-IR Photometry of the Pleiades, and a New List Of
ApJS, in press; version with embedded figures can be obtained at http://spider.ipac.caltech.edu/staff/stauffer/ Near and Mid-IR Photometry of the Pleiades, and a New List of Substellar Candidate Members1,2 John R. Stauffer Spitzer Science Center, Caltech 314-6, Pasadena, CA 91125 [email protected] Lee W. Hartmann Astronomy Department, University of Michigan Giovanni G. Fazio, Lori E. Allen, Brian M. Patten Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 Patrick J. Lowrance, Robert L. Hurt, Luisa M. Rebull Spitzer Science Center, Caltech , Pasadena, CA 91125 Roc M. Cutri, Solange V. Ramirez Infrared Processing and Analysis Center, Caltech 220-6, Pasadena, CA 91125 Erick T. Young, George H. Rieke, Nadya I. Gorlova3, James C. Muzerolle Steward Observatory, University of Arizona, Tucson, AZ 85726 Cathy L. Slesnick Astronomy Department, Caltech, Pasadena, CA 91125 arXiv:0704.1832v1 [astro-ph] 13 Apr 2007 Michael F. Skrutskie Astronomy Department, University of Virginia, Charlottesville, VA 22903 1This work is based (in part) on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under NASA contract 1407. 2This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. 3Current address: University of Florida, 211 Bryant Space Center, Gainesville, FL 32611 –2– ABSTRACT We make use of new near and mid-IR photometry of the Pleiades cluster in order to help identify proposed cluster members. -
Chapter 16 the Sun and Stars
Chapter 16 The Sun and Stars Stargazing is an awe-inspiring way to enjoy the night sky, but humans can learn only so much about stars from our position on Earth. The Hubble Space Telescope is a school-bus-size telescope that orbits Earth every 97 minutes at an altitude of 353 miles and a speed of about 17,500 miles per hour. The Hubble Space Telescope (HST) transmits images and data from space to computers on Earth. In fact, HST sends enough data back to Earth each week to fill 3,600 feet of books on a shelf. Scientists store the data on special disks. In January 2006, HST captured images of the Orion Nebula, a huge area where stars are being formed. HST’s detailed images revealed over 3,000 stars that were never seen before. Information from the Hubble will help scientists understand more about how stars form. In this chapter, you will learn all about the star of our solar system, the sun, and about the characteristics of other stars. 1. Why do stars shine? 2. What kinds of stars are there? 3. How are stars formed, and do any other stars have planets? 16.1 The Sun and the Stars What are stars? Where did they come from? How long do they last? During most of the star - an enormous hot ball of gas day, we see only one star, the sun, which is 150 million kilometers away. On a clear held together by gravity which night, about 6,000 stars can be seen without a telescope. -
STARS, PLANETS and GALAXIES 13-18 April Dahlem, Berlin
STARS, PLANETS AND GALAXIES 13-18 April Dahlem, Berlin Friday, 13 April STRUCTURE FORMATION: FROM COSMOLOGICAL TO ISM SCALES 12h15 Drinks and light lunch available 13h15 Guinevere Kauffmann Welcome 13h30 Philippe Andre The Interstellar Medium and Star Formation: Observations. 14h00 Simon White The Origin of the Cosmic Web of Structure on Large Scales 14h30 Oliver Hahn Shocks and Caustics and their importance for galaxy formation 15h00 Eva Grebel Environmental dependence of stellar chemical evolution and dependence on galaxy properties 15h30 COFFEE BREAK 16h00 Daniel Price Star formation and the role of magnetic fields and turbulence 16h30 Thorsten Naab Simulations of Interstellar Medium and Star formation in Galaxies 17h00 Volker Springel Multi-scale, multi-physics simulation methods. 17h30 DISCUSSION (organizer: G. Kauffmann) 18h30 Reception - Dinner at Harnack House ------------------------------------------------------------------------------------------------------------------- Saturday, 14 April DYNAMICAL PROCESSES IN PLANETS, STARS AND GALAXIES 9h00 Sean Andrews Small-Scale Substructures in Protoplanetary Disks 9h30 Ruth Murray-Clay Pebble Accretion in Protoplanetary Disks 10h00 Francoise Combes Dynamical Processes in Galaxies 10h30 Kathryn Johnston Physical Manifestations of Chaos and Regularity Around Galaxies 11h00 COFFEE 11h30 Scott Tremaine Statistical mechanics of self-gravitating N-body systems 12h00 Silvia Toonen Evolution & interaction in stellar binaries and multiples. 12h30 LUNCH FREE AFTERNOON FOR DISCUSSION/RECREATION -
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). -
10. Scientific Programme 10.1
10. SCIENTIFIC PROGRAMME 10.1. OVERVIEW (a) Invited Discourses Plenary Hall B 18:00-19:30 ID1 “The Zoo of Galaxies” Karen Masters, University of Portsmouth, UK Monday, 20 August ID2 “Supernovae, the Accelerating Cosmos, and Dark Energy” Brian Schmidt, ANU, Australia Wednesday, 22 August ID3 “The Herschel View of Star Formation” Philippe André, CEA Saclay, France Wednesday, 29 August ID4 “Past, Present and Future of Chinese Astronomy” Cheng Fang, Nanjing University, China Nanjing Thursday, 30 August (b) Plenary Symposium Review Talks Plenary Hall B (B) 8:30-10:00 Or Rooms 309A+B (3) IAUS 288 Astrophysics from Antarctica John Storey (3) Mon. 20 IAUS 289 The Cosmic Distance Scale: Past, Present and Future Wendy Freedman (3) Mon. 27 IAUS 290 Probing General Relativity using Accreting Black Holes Andy Fabian (B) Wed. 22 IAUS 291 Pulsars are Cool – seriously Scott Ransom (3) Thu. 23 Magnetars: neutron stars with magnetic storms Nanda Rea (3) Thu. 23 Probing Gravitation with Pulsars Michael Kremer (3) Thu. 23 IAUS 292 From Gas to Stars over Cosmic Time Mordacai-Mark Mac Low (B) Tue. 21 IAUS 293 The Kepler Mission: NASA’s ExoEarth Census Natalie Batalha (3) Tue. 28 IAUS 294 The Origin and Evolution of Cosmic Magnetism Bryan Gaensler (B) Wed. 29 IAUS 295 Black Holes in Galaxies John Kormendy (B) Thu. 30 (c) Symposia - Week 1 IAUS 288 Astrophysics from Antartica IAUS 290 Accretion on all scales IAUS 291 Neutron Stars and Pulsars IAUS 292 Molecular gas, Dust, and Star Formation in Galaxies (d) Symposia –Week 2 IAUS 289 Advancing the Physics of Cosmic -
GU Monocerotis: a High-Mass Eclipsing Overcontact Binary in the Young Open Cluster Dolidze 25? J
A&A 590, A45 (2016) Astronomy DOI: 10.1051/0004-6361/201628224 & c ESO 2016 Astrophysics GU Monocerotis: A high-mass eclipsing overcontact binary in the young open cluster Dolidze 25? J. Lorenzo1, I. Negueruela1, F. Vilardell2, S. Simón-Díaz3; 4, P. Pastor5, and M. Méndez Majuelos6 1 Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Escuela Politécnica Superior, Universidad de Alicante, Carretera de San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Alicante, Spain e-mail: [email protected] 2 Institut d’Estudis Espacials de Catalunya, Edifici Nexus, c/ Capitá, 2−4, desp. 201, 08034 Barcelona, Spain 3 Instituto de Astrofísica de Canarias, Vía Láctea s/n, 38200 La Laguna, Tenerife, Spain 4 Departamento de Astrofísica, Universidad de La Laguna, Facultad de Física y Matemáticas, Avda. Astrofísico Francisco Sánchez s/n, 38205 La Laguna, Tenerife, Spain 5 Departamento de Lenguajes y Sistemas Informáticos, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain 6 Departamento de Ciencias, IES Arroyo Hondo, c/ Maestro Manuel Casal 2, 11520 Rota, Cádiz, Spain Received 30 January 2016 / Accepted 3 March 2016 ABSTRACT Context. The eclipsing binary GU Mon is located in the star-forming cluster Dolidze 25, which has the lowest metallicity measured in a Milky Way young cluster. Aims. GU Mon has been identified as a short-period eclipsing binary with two early B-type components. We set out to derive its orbital and stellar parameters. Methods. We present a comprehensive analysis, including B and V light curves and 11 high-resolution spectra, to verify the orbital period and determine parameters. -
Uvsat: a Concept of an Ultraviolet/Optical Photometric Satellite
UVSat: a concept of an ultraviolet/optical photometric satellite A. Pigulski1, A. Baran2, M. Bzowski3, H. Cugier1, B. Czerny4, J. Daszy´nska-Daszkiewicz1, W. Dziembowski5·6, G. Handler5, Z. Ko laczkowski1, M. Kr´olikowska3, J. Krzesi´nski2, G. Maciejewski7, G. Michalska1, J. Molenda-Zakowicz_ 1, P. Moskalik5, A. Niedzielski7, E. Niemczura1, J. Ostrowski1, A. Pamyatnykh5, M. Ratajczak1, S. Rucinski8, M. Siwak2, R. Smolec5, S. Szutowicz3, T. Tomov7,L. Wyrzykowski6, S. Zo la9 and M. Sarna5 1. Instytut Astronomiczny, Uniwersytet Wroc lawski, Kopernika 11, 51-622 Wroc law, Poland 2. Instytut Fizyki Uniwersytetu Pedagogicznego, Podchora_zych, 2, 30-084 Krak´ow, Poland 3. Centrum Bada´nKosmicznych PAN, Bartycka 18a, 00-716 Warszawa, Poland 4. Centrum Fizyki Teoretycznej PAN, Al. Lotnik´ow 32/46, 02-668 Warszawa, Poland 5. Centrum Astronomiczne im. M. Kopernika PAN, Bartycka 18, 00-716 Warszawa, Poland 6. Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Al. Ujazdowskie 4, 00-478 Warszawa, Poland 7. Centrum Astronomii, Wydzia lFizyki, Astronomii i Informatyki Stosowanej, Uniwersytet Miko laja Kopernika, Grudziadzka, 5, 87-100 Toru´n, Poland 8. Department of Astronomy & Astrophysics, University of Toronto, 50 St. George Street, Toronto, Canada 9. Obserwatorium Astronomiczne Uniwersytetu Jagiello´nskiego, Orla 171, 30-244 Krak´ow, Poland Time-series photometry from space in the ultraviolet can be presently done with only a few platforms, none of which is able to provide wide-field long-term high- cadence photometry. We present a concept of UVSat, a twin space telescope which will be capable to perform this kind of photometry, filling an observational niche. The satellite will host two telescopes, one for observations in the ultravi- olet, the other for observations in the optical band. -
A New Universe to Discover: a Guide to Careers in Astronomy
A New Universe to Discover A Guide to Careers in Astronomy Published by The American Astronomical Society What are Astronomy and Astrophysics? Ever since Galileo first turned his new-fangled one-inch “spyglass” on the moon in 1609, the popular image of the astronomer has been someone who peers through a telescope at the night sky. But astronomers virtually never put eye to lens these days. The main source of astronomical data is still photons (particles of light) from space, but the tools used to gather and analyze them are now so sophisticated that it’s no longer necessary (or even possible, in most cases) for a human eye to look through them. But for all the high-tech gadgetry, the 21st-Century astronomer is still trying to answer the same fundamental questions that puzzled Galileo: How does the universe work, and where did it come from? Webster’s dictionary defines “astronomy” as “the science that deals with the material universe beyond the earth’s atmosphere.” This definition is broad enough to include great theoretical physicists like Isaac Newton, Albert Einstein, and Stephen Hawking as well as astronomers like Copernicus, Johanes Kepler, Fred Hoyle, Edwin Hubble, Carl Sagan, Vera Rubin, and Margaret Burbidge. In fact, the words “astronomy” and “astrophysics” are pretty much interchangeable these days. Whatever you call them, astronomers seek the answers to many fascinating and fundamental questions. Among them: *Is there life beyond earth? *How did the sun and the planets form? *How old are the stars? *What exactly are dark matter and dark energy? *How did the Universe begin, and how will it end? Astronomy is a physical (non-biological) science, like physics and chemistry. -
Ioptron CEM40 Center-Balanced Equatorial Mount
iOptron®CEM40 Center-Balanced Equatorial Mount Instruction Manual Product CEM40 (#7400A series) and CEM40EC (#7400ECA series, as shown) Please read the included CEM40 Quick Setup Guide (QSG) BEFORE taking the mount out of the case! This product is a precision instrument. Please read the included QSG before assembling the mount. Please read the entire Instruction Manual before operating the mount. You must hold the mount firmly when disengaging the gear switches. Otherwise personal injury and/or equipment damage may occur. Any worm system damage due to improper operation will not be covered by iOptron’s limited warranty. If you have any questions please contact us at [email protected] WARNING! NEVER USE A TELESCOPE TO LOOK AT THE SUN WITHOUT A PROPER FILTER! Looking at or near the Sun will cause instant and irreversible damage to your eye. Children should always have adult supervision while using a telescope. 2 Table of Contents Table of Contents ........................................................................................................................................ 3 1. CEM40 Introduction ............................................................................................................................... 5 2. CEM40 Overview ................................................................................................................................... 6 2.1. Parts List ......................................................................................................................................... -
Lars Hernquist and Volker Springel Receive $500,000 Gruber Cosmology Prize
Media Contact: A. Sarah Hreha +1 (203) 432‐6231 [email protected] Online Newsroom: https://gruber.yale.edu/news‐media Lars Hernquist and Volker Springel Receive $500,000 Gruber Cosmology Prize Lars Hernquist Volker Springel New Haven, CT — The 2020 Gruber Cosmology Prize recognizes Lars Hernquist, Center for Astrophysics | Harvard & Smithsonian, and Volker Springel, Max Planck Institute for Astrophysics, for their defining contributions to cosmological simulations, a method that tests existing theories of, and inspires new investigations into, the formation of structures at every scale from stars to galaxies to the universe itself. Hernquist and Springel will divide the $500,000 award, and each will receive a gold laureate pin at a ceremony that will take place later this year. The award recognizes their transformative work on structure formation in the universe, and development of numerical algorithms and community codes further used by many other researchers to significantly advance the field. Hernquist was a pioneer in cosmological simulations when he joined the fledgling field in the late 1980s, and since then he has become one of its most influential figures. Springel, who entered the field in 1998 and first partnered with Hernquist in the early 2000s, has written and applied several of the most widely used codes in cosmological research. Together Hernquist and Springel constitute, in the words of one Gruber Prize nominator, “one of the most productive collaborations ever in cosmology.” Computational simulations in cosmology begin with the traditional source of astronomical data: observations of the universe. Then, through a combination of theory and known physics that might approximate initial conditions, the simulations recreate the subsequent processes that would have led to the current structure. -
Arxiv:0908.2624V1 [Astro-Ph.SR] 18 Aug 2009
Astronomy & Astrophysics Review manuscript No. (will be inserted by the editor) Accurate masses and radii of normal stars: Modern results and applications G. Torres · J. Andersen · A. Gim´enez Received: date / Accepted: date Abstract This paper presents and discusses a critical compilation of accurate, fun- damental determinations of stellar masses and radii. We have identified 95 detached binary systems containing 190 stars (94 eclipsing systems, and α Centauri) that satisfy our criterion that the mass and radius of both stars be known to ±3% or better. All are non-interacting systems, so the stars should have evolved as if they were single. This sample more than doubles that of the earlier similar review by Andersen (1991), extends the mass range at both ends and, for the first time, includes an extragalactic binary. In every case, we have examined the original data and recomputed the stellar parameters with a consistent set of assumptions and physical constants. To these we add interstellar reddening, effective temperature, metal abundance, rotational velocity and apsidal motion determinations when available, and we compute a number of other physical parameters, notably luminosity and distance. These accurate physical parameters reveal the effects of stellar evolution with un- precedented clarity, and we discuss the use of the data in observational tests of stellar evolution models in some detail. Earlier findings of significant structural differences between moderately fast-rotating, mildly active stars and single stars, ascribed to the presence of strong magnetic and spot activity, are confirmed beyond doubt. We also show how the best data can be used to test prescriptions for the subtle interplay be- tween convection, diffusion, and other non-classical effects in stellar models.