The Triple-Ring Nebula: Fingerprint of a Binary Merger1 (Or Supernova 1987A: a Mystery Solved)
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Enhanced Mass Loss Rates in Red Supergiants and Their Impact in The
Revista Mexicana de Astronom´ıa y Astrof´ısica, 55, 161–175 (2019) DOI: https://doi.org/10.22201/ia.01851101p.2019.55.02.04 ENHANCED MASS LOSS RATES IN RED SUPERGIANTS AND THEIR IMPACT ON THE CIRCUMSTELLAR MEDIUM L. Hern´andez-Cervantes1,2, B. P´erez-Rend´on3, A. Santill´an4, G. Garc´ıa-Segura5, and C. Rodr´ıguez-Ibarra6 Received September 25 2018; accepted May 8 2019 ABSTRACT In this work, we present models of massive stars between 15 and 23 M⊙, with enhanced mass loss rates during the red supergiant phase. Our aim is to explore the impact of extreme red supergiant mass-loss on stellar evolution and on their cir- cumstellar medium. We computed a set of numerical experiments, on the evolution of single stars with initial masses of 15, 18, 20 and, 23 M⊙, and solar composi- tion (Z = 0.014), using the numerical stellar code BEC. From these evolutionary models, we obtained time-dependent stellar wind parameters, that were used ex- plicitly as inner boundary conditions in the hydrodynamical code ZEUS-3D, which simulates the gas dynamics in the circumstellar medium (CSM), thus coupling the stellar evolution to the dynamics of the CSM. We found that stars with extreme mass loss in the RSG phase behave as a larger mass stars. RESUMEN En este trabajo presentamos modelos evolutivos de estrellas en el intervalo de 15 a 23 M⊙, usando un incremento en la tasa de p´erdida de masa durante su fase de supergigante roja para explorar el impacto de una fuerte p´erdida de masa en la evoluci´on de la estrella y en la din´amica de su medio circunestelar. -
Science Fiction and Astronomy
Sci Fi Science Fiction and Astronomy Many science fiction books include subjects of astronomical interest. Here is a list of some that have been recommended to me or I’ve read. I expect that most are not in the University library but many are available in Kindle and other e-formats. At the top of my list is a URL to a much longer list by Andrew Fraknoi of the Astronomical Society of the Pacific. Each title in his list has a very brief summary indicating the kind of story it is. Andrew Fraknoi’s list (http://www.astrosociety.org/education/resources/scifi.html). Gregory Benford is a plasma physicist who has been rated by some as one of the finest observes and interpreters of science in modern fiction. Note: Timescape [Vista, ISBN 0575600500] In the Ocean of Night [Vista, ISBN 0575600357] Across the Sea of Suns [Vista, ISBN 0575600551] Great Sky River [Gallancy, ISBN 0575058315] Eater and over 2 dozen more available as e-books. Stephen Baxter Titan [Voyager, 1997, ISBN 0002254247] has been strongly recommended by New Scientist as a tense, near future, thriller you shouldn’t miss. David Brin has a PhD in astrophysics with which he brings real understanding of the Universe to his stories. The Crystal Spheres won an award. Fred Hoyle is probably the most famous astronomer to have written science fiction. The Back Cloud [Macmillan, ISBN 0333556011] is his classic, followed by A for Andromeda. Try also October the First is too late. Larry Niven’s stories include plenty of ideas inspired by modern astronomy. -
A Magnetar Model for the Hydrogen-Rich Super-Luminous Supernova Iptf14hls Luc Dessart
A&A 610, L10 (2018) https://doi.org/10.1051/0004-6361/201732402 Astronomy & © ESO 2018 Astrophysics LETTER TO THE EDITOR A magnetar model for the hydrogen-rich super-luminous supernova iPTF14hls Luc Dessart Unidad Mixta Internacional Franco-Chilena de Astronomía (CNRS, UMI 3386), Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile e-mail: [email protected] Received 2 December 2017 / Accepted 14 January 2018 ABSTRACT Transient surveys have recently revealed the existence of H-rich super-luminous supernovae (SLSN; e.g., iPTF14hls, OGLE-SN14-073) that are characterized by an exceptionally high time-integrated bolometric luminosity, a sustained blue optical color, and Doppler- broadened H I lines at all times. Here, I investigate the effect that a magnetar (with an initial rotational energy of 4 × 1050 erg and 13 field strength of 7 × 10 G) would have on the properties of a typical Type II supernova (SN) ejecta (mass of 13.35 M , kinetic 51 56 energy of 1:32 × 10 erg, 0.077 M of Ni) produced by the terminal explosion of an H-rich blue supergiant star. I present a non-local thermodynamic equilibrium time-dependent radiative transfer simulation of the resulting photometric and spectroscopic evolution from 1 d until 600 d after explosion. With the magnetar power, the model luminosity and brightness are enhanced, the ejecta is hotter and more ionized everywhere, and the spectrum formation region is much more extended. This magnetar-powered SN ejecta reproduces most of the observed properties of SLSN iPTF14hls, including the sustained brightness of −18 mag in the R band, the blue optical color, and the broad H I lines for 600 d. -
Science Fiction Stories with Good Astronomy & Physics
Science Fiction Stories with Good Astronomy & Physics: A Topical Index Compiled by Andrew Fraknoi (U. of San Francisco, Fromm Institute) Version 7 (2019) © copyright 2019 by Andrew Fraknoi. All rights reserved. Permission to use for any non-profit educational purpose, such as distribution in a classroom, is hereby granted. For any other use, please contact the author. (e-mail: fraknoi {at} fhda {dot} edu) This is a selective list of some short stories and novels that use reasonably accurate science and can be used for teaching or reinforcing astronomy or physics concepts. The titles of short stories are given in quotation marks; only short stories that have been published in book form or are available free on the Web are included. While one book source is given for each short story, note that some of the stories can be found in other collections as well. (See the Internet Speculative Fiction Database, cited at the end, for an easy way to find all the places a particular story has been published.) The author welcomes suggestions for additions to this list, especially if your favorite story with good science is left out. Gregory Benford Octavia Butler Geoff Landis J. Craig Wheeler TOPICS COVERED: Anti-matter Light & Radiation Solar System Archaeoastronomy Mars Space Flight Asteroids Mercury Space Travel Astronomers Meteorites Star Clusters Black Holes Moon Stars Comets Neptune Sun Cosmology Neutrinos Supernovae Dark Matter Neutron Stars Telescopes Exoplanets Physics, Particle Thermodynamics Galaxies Pluto Time Galaxy, The Quantum Mechanics Uranus Gravitational Lenses Quasars Venus Impacts Relativity, Special Interstellar Matter Saturn (and its Moons) Story Collections Jupiter (and its Moons) Science (in general) Life Elsewhere SETI Useful Websites 1 Anti-matter Davies, Paul Fireball. -
The Drink Tank Sixth Annual Giant Sized [email protected]: James Bacon & Chris Garcia
The Drink Tank Sixth Annual Giant Sized Annual [email protected] Editors: James Bacon & Chris Garcia A Noise from the Wind Stephen Baxter had got me through the what he’ll be doing. I first heard of Stephen Baxter from Jay night. So, this is the least Giant Giant Sized Crasdan. It was a night like any other, sitting in I remember reading Ring that next Annual of The Drink Tank, but still, I love it! a room with a mostly naked former ballerina afternoon when I should have been at class. I Dedicated to Mr. Stephen Baxter. It won’t cover who was in the middle of what was probably finished it in less than 24 hours and it was such everything, but it’s a look at Baxter’s oevre and her fifth overdose in as many months. This was a blast. I wasn’t the big fan at that moment, the effect he’s had on his readers. I want to what we were dealing with on a daily basis back though I loved the novel. I had to reread it, thank Claire Brialey, M Crasdan, Jay Crasdan, then. SaBean had been at it again, and this time, and then grabbed a copy of Anti-Ice a couple Liam Proven, James Bacon, Rick and Elsa for it was up to me and Jay to clean up the mess. of days later. Perhaps difficult times made Ring everything! I had a blast with this one! Luckily, we were practiced by this point. Bottles into an excellent escape from the moment, and of water, damp washcloths, the 9 and the first something like a month later I got into it again, 1 dialed just in case things took a turn for the and then it hit. -
The Life Cycle of the Stars Chart
NAME__________________________________DATE_______________PER________ The Life Cycle of the Stars Chart Refer to the “Life Cycle of the Stars Notes and the following terms to fill in the labels on the chart: Black Hole (Forms after the supernova of a massive star that is more than 5 times the mass of the sun) Black Dwarf Star (The remains of a white dwarf that no longer shines) Blue Supergiant Star (more than 3 times more massive than our sun) Nebula (clouds of interstellar dust and gas) Neutron Star (Forms after the supernova of a massive star. Neutron stars are about 10-20 km in diameter but 1.4 times the mass of sun) Planetary or Ring Nebula (the aftermath of a Red Giant that goes “nova”, which means it expels it outer layers) Red Dwarf Star ( a main sequence star of small size and lower temperature) Red Giant Star ( Forms from sun-like stars that start fusing helium. The star expands and cools to a red giant) Red Supergiant Star (Forms from massive stars that start fusing helium. The star expands and cools to a supergiant) Sun-Like Star (a yellow medium-sized star) Supernova (Occurs after a massive star produces iron which cannot be fused further. The result us a massive explosion) White Dwarf (The left-over core of a red giant that has expelled its outer layers. It may continue to shine for billions of years) Color all stars (except neutron star) the appropriate color with colored pencil or marker. Color nebulas red and orange. Do not color supernovas and black holes. -
Frontiers in Coalescent Theory: Pedigrees, Identity-By-Descent, and Sequentially Markov Coalescent Models
Frontiers in Coalescent Theory: Pedigrees, Identity-by-Descent, and Sequentially Markov Coalescent Models The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Wilton, Peter R. 2016. Frontiers in Coalescent Theory: Pedigrees, Identity-by-Descent, and Sequentially Markov Coalescent Models. Doctoral dissertation, Harvard University, Graduate School of Arts & Sciences. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493608 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 Frontiers in Coalescent Theory: Pedigrees, Identity-by-descent, and Sequentially Markov Coalescent Models a dissertation presented by Peter Richard Wilton to The Department of Organismic and Evolutionary Biology in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of Biology Harvard University Cambridge, Massachusetts May 2016 ©2016 – Peter Richard Wilton all rights reserved. Thesis advisor: Professor John Wakeley Peter Richard Wilton Frontiers in Coalescent Theory: Pedigrees, Identity-by-descent, and Sequentially Markov Coalescent Models Abstract The coalescent is a stochastic process that describes the genetic ancestry of individuals sampled from a population. It is one of the main tools of theoretical population genetics and has been used as the basis of many sophisticated methods of inferring the demo- graphic history of a population from a genetic sample. This dissertation is presented in four chapters, each developing coalescent theory to some degree. -
Black Hole Central Engine for Ultra-Long Gamma-Ray Burst
DRAFT VERSION OCTOBER 16, 2018 Preprint typeset using LATEX style emulateapj v. 5/2/11 BLACK HOLE CENTRAL ENGINE FOR ULTRA-LONG GAMMA-RAY BURST 111209A AND ITS ASSOCIATED SUPERNOVA 2011KL HE GAO1 ,WEI-HUA LEI2,ZHI-QIANG YOU1 AND WEI XIE2 Draft version October 16, 2018 ABSTRACT Recently, the first association between an ultra-long gamma-ray burst (GRB) and a supernovais reported, i.e., GRB 111209A/SN 2011kl, which enables us to investigate the physics of central engines or even progenitors for ultra-long GRBs. In this paper, we inspect the broad-band data of GRB 111209A/SN 2011kl. The late- time X-ray lightcurve exhibits a GRB 121027A-like fall-back bump, suggesting a black hole central engine. We thus propose a collapsar model with fall-back accretion for GRB 111209A/SN 2011kl. The required model parameters, such as the total mass and radius of the progenitorstar, suggest that the progenitorof GRB 111209A is more likely a Wolf-Rayet star instead of blue supergiant, and the central engine of this ultra-long burst is a black hole. The implications of our results is discussed. Subject headings: accretion, accretion disks - black hole physics - gamma-ray burst: individual (GRB 111209A) 1. INTRODUCTION tized millisecond neutronstar (a magnetar) (Levan et al. 2014; Recently, “ultra-long bursts”, a subclass of gamma-ray Greiner et al. 2015). Research on the physical origin of ultra- bursts (GRBs) with unusually long central engine activity (∼ long GRBs would potentially promote our understanding of hours) compared to typical GRBs (tens of seconds), have been the central engine and progenitor of GRBs. -
2. Descriptive Astronomy (“Astronomy Without a Telescope”)
•How do we locate stars in the heavens? •What stars are visible from a given location? 2. Descriptive Astronomy •Where is the sun in the sky at any given time? (Astronomy Without a Telescope) •Where are you on the Earth? http://www.star.ucl.ac.uk/~idh/apod/ In 1930 the International Astronomical Union (IAU) ruled the heavens off into 88 legal, precise constellations. Every star, galaxy, etc., is a member of one of these constellations. Many stars are named according to their constellation and relative brightness (Bayer 1603). Sirius Centauri, -Canis see http://calgary.rasc.ca/constellation.htm#list Majoris, -Orionis An asterism is two stars that appear http://www.google.com/sky/ Betelgeuse To be close in the sky but actually arent http://www.seds.org/messier/ (1758 – 1782) Brief History E.g., ORION Some of the current constellations can be traced back to the inhabitants of the Euphrates valley, from whom they were handed down through the Greeks and Arabs. Few pictorial records of the ancient constellation figures have survived, but in the Almagest AD 150, Ptolemy catalogued the positions of 1,022 of the brightest stars both in terms of celestial latitude and longitude, and of their places in 48 constellations. The Ptolemaic constellations left a blank area centered not on the present south pole but on a point which, because of precession, would have been the south pole c. 2800 BC, a fact that is consistent with the belief that the constellation system had its origin about 5,000 Betelgeuse and Rigel are M42 = Orion nebula M43 = DeMairans nebula years ago. -
Recent Progress in Coalescent Theory
SOCIEDADEBRASILEIRADEMATEMÁTICA ENSAIOS MATEMATICOS´ 200X, Volume XX, X–XX Recent Progress in Coalescent Theory Nathana¨el Berestycki Abstract. Coalescent theory is the study of random processes where particles may join each other to form clusters as time evolves. These notes provide an introduction to some aspects of the mathe- matics of coalescent processes and their applications to theoretical population genetics and other fields such as spin glass models. The emphasis is on recent work concerning in particular the connection of these processes to continuum random trees and spatial models such as coalescing random walks. arXiv:0909.3985v1 [math.PR] 22 Sep 2009 2000 Mathematics Subject Classification: 60J25, 60K35, 60J80. Introduction The probabilistic theory of coalescence, which is the primary subject of these notes, has expanded at a quick pace over the last decade or so. I can think of three factors which have essentially contributed to this growth. On the one hand, there has been a rising demand from population geneticists to develop and analyse models which incorporate more realistic features than what Kingman’s coalescent allows for. Simultaneously, the field has matured enough that a wide range of techniques from modern probability theory may be success- fully applied to these questions. These tools include for instance martingale methods, renormalization and random walk arguments, combinatorial embeddings, sample path analysis of Brownian motion and L´evy processes, and, last but not least, continuum random trees and measure-valued processes. Finally, coalescent processes arise in a natural way from spin glass models of statistical physics. The identification of the Bolthausen-Sznitman coalescent as a universal scaling limit in those models, and the connection made by Brunet and Derrida to models of population genetics, is a very exciting re- cent development. -
Pulsar Wind Nebulae and Their Supernovae 3 Two Other Cases (0540–69 and G292.0+1.8), There Is an Age Estimate from the Expansion of Optical filaments
Young Neutron Stars and Their Environments IAU Symposium, Vol. 218, 2004 F. Camilo and B. M. Gaensler, eds. Pulsar Wind Nebulae and Their Supernovae Roger A. Chevalier Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903, USA Abstract. Young supernova remnants that contain pulsar wind nebulae provide diagnostics for both the inner part of the supernova and the interaction with the surrounding medium, providing an opportunity to relate these objects to supernova types. Among observed young nebulae, there is evidence for a range of supernova types, including Type IIP (Crab Nebula and SN 1054) and Type IIb/IIn/IIL (G292.0+1.8). 1. Introduction Recent X-ray satellites (ASCA, Chandra, and Newton XMM) have substantially increased the number of observed young PWNe (pulsar wind nebulae), as well as adding to our knowledge of the nebulae and their surrounding supernova remnants. Young PWNe are expected to be interacting with freely expanding ejecta in the interior of a supernova, providing a probe of the inner parts of the supernova. The surrounding supernova remnant is typically interacting with circumstellar mass loss from the progenitor star. The combination of this infor- mation can be related to our expections for core-collapse supernovae and their surroundings. Here, I examine the properties of 8 young PWNe in this context. 2. Supernovae and their surroundings Recent observations of core-collapse supernovae at X-ray and radio wavelengths arXiv:astro-ph/0310730v1 24 Oct 2003 have yielded a fairly complete picture of the circumstellar surroundings of the various supernova types (Chevalier 2003a). Although the numbers are still small, Type IIP (plateau) supernovae have been found to be relatively weak X-ray and radio sources, with a mass loss density corresponding to a mass loss rate −6 −1 −1 M˙ ≈ 10 M⊙ yr for a wind velocity of vw = 10 km s ; the light curves of these supernovae indicate red supergiant progenitors. -
Lab Title: Observing Project – Orion, Saturn, and the Moon Your Name
Lab Title: Observing Project – Orion, Saturn, and the Moon Your name:___________________________ Instructor's Initials:_________ Lab partners:_______________________________________________________ Your write-up for this lab shall contain answers to all the questions in this lab. You will be able to write most of your answers in the space provided in this write-up, but some discussion of your observations should be written up separately at the end. No Conclusions section is required for this exercise. If you write down notes on your observations, hand those in as well. Purpose: In this lab you will get a chance to observe three objects in the constellation Orion – the red supergiant star Betelgeuse, the blue supergiant star Rigel, and Orion’s nebula. You will then apply principles of blackbody radiation to estimate some of the properties of these objects. Finally, we’ll re-visit Saturn and the Moon for some more detailed observations. Required materials: 1. Warm clothes (even though the daytime temperatures are fairly warm, it still cools off quickly after dark, and you won't be moving around much). 2. If you have one, a flashlight covered with red cellophane or similar material (to preserve night vision). 3. Pencil, eraser, and blank sheets of paper for sketches. 4. For the write-up you will need a scientific calculator, access to an introductory astronomy textbook, and a computer with internet access. Introduction: Betelgeuse The great star Betelgeuse, also called Alpha Orionis, is one of the two stars that dominate the constellation Orion. We will come to the other, Rigel, in a moment.