SN 1054, SN 1006, & Nova WZ Sagittae
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
FY08 Technical Papers by GSMTPO Staff
AURA/NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation July 23, 2008 Revised as Complete and Submitted December 23, 2008 NGC 660, ~13 Mpc from the Earth, is a peculiar, polar ring galaxy that resulted from two galaxies colliding. It consists of a nearly edge-on disk and a strongly warped outer disk. Image Credit: T.A. Rector/University of Alaska, Anchorage NATIONAL OPTICAL ASTRONOMY OBSERVATORY NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation December 23, 2008 TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................................. 1 1 SCIENTIFIC ACTIVITIES AND FINDINGS ..................................................................................... 2 1.1 Cerro Tololo Inter-American Observatory...................................................................................... 2 The Once and Future Supernova η Carinae...................................................................................................... 2 A Stellar Merger and a Missing White Dwarf.................................................................................................. 3 Imaging the COSMOS...................................................................................................................................... 3 The Hubble Constant from a Gravitational Lens.............................................................................................. 4 A New Dwarf Nova in the Period Gap............................................................................................................ -
A Hot Subdwarf-White Dwarf Super-Chandrasekhar Candidate
A hot subdwarf–white dwarf super-Chandrasekhar candidate supernova Ia progenitor Ingrid Pelisoli1,2*, P. Neunteufel3, S. Geier1, T. Kupfer4,5, U. Heber6, A. Irrgang6, D. Schneider6, A. Bastian1, J. van Roestel7, V. Schaffenroth1, and B. N. Barlow8 1Institut fur¨ Physik und Astronomie, Universitat¨ Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, D-14476 Potsdam-Golm, Germany 2Department of Physics, University of Warwick, Coventry, CV4 7AL, UK 3Max Planck Institut fur¨ Astrophysik, Karl-Schwarzschild-Straße 1, 85748 Garching bei Munchen¨ 4Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA 5Texas Tech University, Department of Physics & Astronomy, Box 41051, 79409, Lubbock, TX, USA 6Dr. Karl Remeis-Observatory & ECAP, Astronomical Institute, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Sternwartstr. 7, 96049 Bamberg, Germany 7Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA 8Department of Physics and Astronomy, High Point University, High Point, NC 27268, USA *[email protected] ABSTRACT Supernova Ia are bright explosive events that can be used to estimate cosmological distances, allowing us to study the expansion of the Universe. They are understood to result from a thermonuclear detonation in a white dwarf that formed from the exhausted core of a star more massive than the Sun. However, the possible progenitor channels leading to an explosion are a long-standing debate, limiting the precision and accuracy of supernova Ia as distance indicators. Here we present HD 265435, a binary system with an orbital period of less than a hundred minutes, consisting of a white dwarf and a hot subdwarf — a stripped core-helium burning star. -
DIRECT DETECTION of the L-DWARF DONOR in WZ SAGITTAE Thomas E
The Astrophysical Journal, 816:4 (6pp), 2016 January 1 doi:10.3847/0004-637X/816/1/4 © 2016. The American Astronomical Society. All rights reserved. DIRECT DETECTION OF THE L-DWARF DONOR IN WZ SAGITTAE Thomas E. Harrison1 Department of Astronomy, New Mexico State University, Box 30001, MSC 4500, Las Cruces, NM 88003-8001, USA Received 2015 September 15; accepted 2015 November 20; published 2015 December 21 ABSTRACT Analysis of a large set of phase-resolved K-band spectra of the cataclysmic variable WZ Sge shows that the secondary star of this system appears to be an L-dwarf. Previous K-band spectra of WZ Sge found that the CO 12 overtone bandheads were in emission. We show that absorption from the CO(2,0) bandhead of the donor star 12 creates a dip in the CO(2,0) emission feature. Measuring the motion of this feature over the orbital period, we −1 construct a radial velocity curve that gives a velocity amplitude of Kabs = 520±35 km s , consistent with the previously published values for this parameter. Key words: brown dwarfs – novae, cataclysmic variables – stars: dwarf novae 1. INTRODUCTION Harrison et al. 2004a) and has a very low accretion rate (Patterson 1998), the donor object has remained elusive. Cataclysmic variables (CVs) are short period binaries where While direct photospheric absorption features from the donor the white dwarf primary is accreting matter from a lower mass in WZ Sge have not previously been detected, Hα emission, secondary star. An angular momentum loss process keeps the ( ) due to the irradiation of the companion during the 2001 system in contact c.f., King & Kolb 1995 , and the orbital outburst, were clearly seen, and led to the first quantitative period shortens over time as the secondary continues to lose constraints on the nature of the secondary. -
EVOLUTION of the CRAB NEBULA in a LOW ENERGY SUPERNOVA Haifeng Yang and Roger A
Draft version August 23, 2018 Preprint typeset using LATEX style emulateapj v. 5/2/11 EVOLUTION OF THE CRAB NEBULA IN A LOW ENERGY SUPERNOVA Haifeng Yang and Roger A. Chevalier Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904; [email protected], [email protected] Draft version August 23, 2018 ABSTRACT The nature of the supernova leading to the Crab Nebula has long been controversial because of the low energy that is present in the observed nebula. One possibility is that there is significant energy in extended fast material around the Crab but searches for such material have not led to detections. An electron capture supernova model can plausibly account for the low energy and the observed abundances in the Crab. Here, we examine the evolution of the Crab pulsar wind nebula inside a freely expanding supernova and find that the observed properties are most consistent with a low energy event. Both the velocity and radius of the shell material, and the amount of gas swept up by the pulsar wind point to a low explosion energy ( 1050 ergs). We do not favor a model in which circumstellar interaction powers the supernova luminosity∼ near maximum light because the required mass would limit the freely expanding ejecta. Subject headings: ISM: individual objects (Crab Nebula) | supernovae: general | supernovae: indi- vidual (SN 1054) 1. INTRODUCTION energy of 1050 ergs (Chugai & Utrobin 2000). However, SN 1997D had a peak absolute magnitude of 14, con- The identification of the supernova type of SN 1054, − the event leading to the Crab Nebula, has been an en- siderably fainter than SN 1054 at maximum. -
Variable Star Classification and Light Curves Manual
Variable Star Classification and Light Curves An AAVSO course for the Carolyn Hurless Online Institute for Continuing Education in Astronomy (CHOICE) This is copyrighted material meant only for official enrollees in this online course. Do not share this document with others. Please do not quote from it without prior permission from the AAVSO. Table of Contents Course Description and Requirements for Completion Chapter One- 1. Introduction . What are variable stars? . The first known variable stars 2. Variable Star Names . Constellation names . Greek letters (Bayer letters) . GCVS naming scheme . Other naming conventions . Naming variable star types 3. The Main Types of variability Extrinsic . Eclipsing . Rotating . Microlensing Intrinsic . Pulsating . Eruptive . Cataclysmic . X-Ray 4. The Variability Tree Chapter Two- 1. Rotating Variables . The Sun . BY Dra stars . RS CVn stars . Rotating ellipsoidal variables 2. Eclipsing Variables . EA . EB . EW . EP . Roche Lobes 1 Chapter Three- 1. Pulsating Variables . Classical Cepheids . Type II Cepheids . RV Tau stars . Delta Sct stars . RR Lyr stars . Miras . Semi-regular stars 2. Eruptive Variables . Young Stellar Objects . T Tau stars . FUOrs . EXOrs . UXOrs . UV Cet stars . Gamma Cas stars . S Dor stars . R CrB stars Chapter Four- 1. Cataclysmic Variables . Dwarf Novae . Novae . Recurrent Novae . Magnetic CVs . Symbiotic Variables . Supernovae 2. Other Variables . Gamma-Ray Bursters . Active Galactic Nuclei 2 Course Description and Requirements for Completion This course is an overview of the types of variable stars most commonly observed by AAVSO observers. We discuss the physical processes behind what makes each type variable and how this is demonstrated in their light curves. Variable star names and nomenclature are placed in a historical context to aid in understanding today’s classification scheme. -
Pulsars and Supernova Remnants
1604–2004: SUPERNOVAE AS COSMOLOGICAL LIGHTHOUSES ASP Conference Series, Vol. 342, 2005 M. Turatto, S. Benetti, L. Zampieri, and W. Shea Pulsars and Supernova Remnants Roger A. Chevalier Dept. of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903, USA Abstract. Massive star supernovae can be divided into four categories de- pending on the amount of mass loss from the progenitor star and the star’s ra- dius. Various aspects of the immediate aftermath of the supernova are expected to develop in different ways depending on the supernova category: mixing in the supernova, fallback on the central compact object, expansion of any pul- sar wind nebula, interaction with circumstellar matter, and photoionization by shock breakout radiation. Models for observed young pulsar wind nebulae ex- panding into supernova ejecta indicate initial pulsar periods of 10 − 100 ms and approximate equipartition between particle and magnetic energies. Considering both pulsar nebulae and circumstellar interaction, the observed properties of young supernova remnants allow many of them to be placed in one of the super- nova categories; the major categories are represented. The pulsar properties do not appear to be related to the supernova category. 1. Introduction The association of SN 1054 with the Crab Nebula and its central pulsar can be understood in the context of the formation of the neutron star in the core collapse and the production of a bubble of relativistic particles and magnetic fields at the center of an expanding supernova. Although the finding of more young pulsars and their wind nebulae initially proceeded slowly, there has recently been a rapid set of discoveries of more such pulsars and nebulae (Camilo 2004). -
Blasts from the Past Historic Supernovas
BLASTS from the PAST: Historic Supernovas 185 386 393 1006 1054 1181 1572 1604 1680 RCW 86 G11.2-0.3 G347.3-0.5 SN 1006 Crab Nebula 3C58 Tycho’s SNR Kepler’s SNR Cassiopeia A Historical Observers: Chinese Historical Observers: Chinese Historical Observers: Chinese Historical Observers: Chinese, Japanese, Historical Observers: Chinese, Japanese, Historical Observers: Chinese, Japanese Historical Observers: European, Chinese, Korean Historical Observers: European, Chinese, Korean Historical Observers: European? Arabic, European Arabic, Native American? Likelihood of Identification: Possible Likelihood of Identification: Probable Likelihood of Identification: Possible Likelihood of Identification: Possible Likelihood of Identification: Definite Likelihood of Identification: Definite Likelihood of Identification: Possible Likelihood of Identification: Definite Likelihood of Identification: Definite Distance Estimate: 8,200 light years Distance Estimate: 16,000 light years Distance Estimate: 3,000 light years Distance Estimate: 10,000 light years Distance Estimate: 7,500 light years Distance Estimate: 13,000 light years Distance Estimate: 10,000 light years Distance Estimate: 7,000 light years Distance Estimate: 6,000 light years Type: Core collapse of massive star Type: Core collapse of massive star Type: Core collapse of massive star? Type: Core collapse of massive star Type: Thermonuclear explosion of white dwarf Type: Thermonuclear explosion of white dwarf? Type: Core collapse of massive star Type: Thermonuclear explosion of white dwarf Type: Core collapse of massive star NASA’s ChANdrA X-rAy ObServAtOry historic supernovas chandra x-ray observatory Every 50 years or so, a star in our Since supernovas are relatively rare events in the Milky historic supernovas that occurred in our galaxy. Eight of the trine of the incorruptibility of the stars, and set the stage for observed around 1671 AD. -
Supernovae 6 Supernovae Stellar Catastrophes 1. Observations
Supernovae 6 Supernovae Stellar Catastrophes 1. Observations Which stars explode? Which collapse? Which outwit the villain gravity and settle down to a quiet old age as a white dwarf? Astrophysicists are beginning to block out answers to these questions. We know that a quiet death eludes some stars. Astronomers observe some stars exploding as supernovae, a sudden brightening by which a single star becomes as bright as an entire galaxy. Estimates of the energy involved in such a process reveal that a major portion of the star, if not the entire star, must be blown to smithereens. Historical records, particularly the careful data recorded by the Chinese, show that seven or eight supernovae have exploded over the last 2000 years in our portion of the Galaxy. The supernova of 1006 was the brightest ever recorded. One could read by this supernova at night. Astronomers throughout the Middle and Far East observed this event. The supernova of 1054 is by far the most famous, although this event is clearly not the only so-called “Chinese guest star.” This explosion produced the rapidly expanding shell of gas that modern astronomers identify as the Crab nebula. The supernova of 1054 was apparently recorded first by the Japanese and was also clearly mentioned by the Koreans, although the Chinese have the most careful records. There is a strong suspicion that Native Americans recorded the event in rock paintings and perhaps on pottery. An entertaining mystery surrounds the question of why there is no mention of the event in European history. One line of thought is that the church had such a grip on people in the Middle Ages that no one having seen the supernova would have dared voice a difference with the dogma of the immutability of the heavens. -
Appendix: Spectroscopy of Variable Stars
Appendix: Spectroscopy of Variable Stars As amateur astronomers gain ever-increasing access to professional tools, the science of spectroscopy of variable stars is now within reach of the experienced variable star observer. In this section we shall examine the basic tools used to perform spectroscopy and how to use the data collected in ways that augment our understanding of variable stars. Naturally, this section cannot cover every aspect of this vast subject, and we will concentrate just on the basics of this field so that the observer can come to grips with it. It will be noticed by experienced observers that variable stars often alter their spectral characteristics as they vary in light output. Cepheid variable stars can change from G types to F types during their periods of oscillation, and young variables can change from A to B types or vice versa. Spec troscopy enables observers to monitor these changes if their instrumentation is sensitive enough. However, this is not an easy field of study. It requires patience and dedication and access to resources that most amateurs do not possess. Nevertheless, it is an emerging field, and should the reader wish to get involved with this type of observation know that there are some excellent guides to variable star spectroscopy via the BAA and the AAVSO. Some of the workshops run by Robin Leadbeater of the BAA Variable Star section and others such as Christian Buil are a very good introduction to the field. © Springer Nature Switzerland AG 2018 M. Griffiths, Observer’s Guide to Variable Stars, The Patrick Moore 291 Practical Astronomy Series, https://doi.org/10.1007/978-3-030-00904-5 292 Appendix: Spectroscopy of Variable Stars Spectra, Spectroscopes and Image Acquisition What are spectra, and how are they observed? The spectra we see from stars is the result of the complete output in visible light of the star (in simple terms). -
The Electron-Capture Origin of Supernova 2018Zd
The electron-capture origin of supernova 2018zd Daichi Hiramatsu1;2∗, D. Andrew Howell1;2, Schuyler D. Van Dyk3, Jared A. Goldberg2, Keiichi Maeda4;5, Takashi J. Moriya6;7, Nozomu Tominaga8;5, Ken’ichi Nomoto5, Griffin Hosseinzadeh9, Iair Arcavi10;11, Curtis McCully1;2, Jamison Burke1;2, K. Azalee Bostroem12, Stefano Valenti12, Yize Dong12, Peter J. Brown13, Jennifer E. Andrews14, Christopher Bilinski14, G. Grant Williams14;15, Paul S. Smith14, Nathan Smith14, David J. Sand14, Gagandeep S. Anand16;17, Chengyuan Xu18, Alexei V.Filippenko19;20, Melina C. Bersten21;22;5, Gaston´ Folatelli21;22;5, Patrick L. Kelly23, Toshi- hide Noguchi24 & Koichi Itagaki25 *Corresponding author. Email: [email protected] 1Las Cumbres Observatory, 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA 2Department of Physics, University of California, Santa Barbara, CA 93106-9530, USA 3Caltech/Spitzer Science Center, Caltech/IPAC, Mailcode 100-22, Pasadena, CA 91125, USA 4Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606- 8502, Japan 5Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277- 8583, Japan arXiv:2011.02176v1 [astro-ph.HE] 4 Nov 2020 6National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Os- awa, Mitaka, Tokyo 181-8588, Japan 7School of Physics and Astronomy, Faculty of Science, Monash University, Clayton, Victoria 1 3800, Australia -
WZ Sagittae Space Weather—Global Warming
Journal of Earth Science and Engineering 7 (2017) 154-174 doi: 10.17265/2159-581X/2017.03.004 D DAVID PUBLISHING WZ Sagittae Space Weather—Global Warming William Sokeland Retired, Heat Transfer Expert, Spacecraft and Turbine Engines, Oakland City, Indiana47660, USA Abstract: The planet responds thermally to the impacts of nova WZ Sagittae debris by heating and cooling. The result in the first 19 years of the nova WZ Sagittae cycle is global warming that is hemi-spherically dependent and is detectable in South America ice core data and Antarctica surface mass balance data. Planetary thermal data are correlated in the past by calculating the debris impact times from the super outbursts times of nova WZ Sagittae. The shape of the arctic ice cap is dependent on the 220 degree path of the debris and does not exist southward between the western extension and eastern termini of nova WZ Sagittae that define the Arctic heating path. Future global heating from nova WZ Sagittae will begin in 2020-2021. The increase of 6 to 8 magnitude unusual earthquakes in recent years is the results of nova WZ Sagittae and SN 1054 debris impact. Unusual occurrences in the biosphere indicate the starting time of impacting supernova debris streams. The Antarctic sea ice distribution in November of 2016 defines the termini of maximum particle concentration impact from supernova 1006 in the southern hemisphere. The killing heat in India of the northern hemisphere is associated with the western terminus of this supernova. Novas and supernovas times of impact correlate with plague outbreaks in the western USA marking the particles in the debris streams as the cause of the disease. -
Supernovae and Neutron Stars
Outline of today’s lecture Lecture 17: •Finish up lecture 16 (nucleosynthesis) •Supernovae •2 main classes: Type II and Type I Supernovae and •Their energetics and observable properties Neutron Stars •Supernova remnants (pretty pictures!) •Neutron Stars •Review of formation http://apod.nasa.gov/apod/ •Pulsars REVIEWS OF MODERN PHYSICS, VOLUME 74, OCTOBER 2002 The evolution and explosion of massive stars S. E. Woosley* and A. Heger† Department of Astronomy and Astrophysics, University of California, Santa Cruz, California 95064 T. A. Weaver Lawrence Livermore National Laboratory, Livermore, California 94551 (Published 7 November 2002) Like all true stars, massive stars are gravitationally confined thermonuclear reactors whose composition evolves as energy is lost to radiation and neutrinos. Unlike lower-mass stars (M Շ8M᭪), however, no point is ever reached at which a massive star can be fully supported by electron degeneracy. Instead, the center evolves to ever higher temperatures, fusing ever heavier elements until a core of iron is produced. The collapse of this iron core to a neutron star releases an enormous amount of energy, a tiny fraction of which is sufficient to explode the star as a supernova. The authors examine our current understanding of the lives and deaths of massive stars, with special attention to the relevant nuclear and stellar physics. Emphasis is placed upon their post-helium-burning evolution. Current views regarding the supernova explosion mechanism are reviewed, and the hydrodynamics of supernova shock propagation and ‘‘fallback’’ is discussed. The calculated neutron star masses, supernova light curves, and spectra from these model stars are shown to be consistent with observations.