Science Briefing October 4, 2018 Deaths and Afterlives of Stars Dr. Bethany Cobb Kung (George Washington University) Dr. Elizabeth Ferrara (University of Maryland / NASA GSFC) Prof. Lynn Cominsky (Sonoma State University) Facilitator: Dr. Brandon Lawton (STScI) Additional Resources http://nasawavelength.org/list/2311 Featured Resources: Gamma-ray Burst Educator Guide (specific activities in Wavelength list)1 Supernova Educator Guide (specific activities in Wavelength list)1 Fermi Pulsar Explorer Merging Neutron Star Resources: Multi-messenger Astronomy: A New Era in Space Science (November 2017 Breaking News Briefing) Multimedia products for LIGO/Virgo Observations Additional Activities: Gamma-ray Bursts and Supernova video Star Maps: Stars Likely to Go Supernova A Universe with Supernovae Stellar Evolution: Our Cosmic Connection How to Hold a Dead Star in Your Hand Supernova Explosions 2 Outline of this Science Briefing 1. Dr. Bethany Cobb Kung (George Washington University) Supernovae, GRBs and Swift 2. Dr. Elizabeth Ferrara (University of Maryland / NASA GSFC) Gravity & Light from Merging Neutron Stars 3. Q & A 4. Prof. Lynn Cominsky (Sonoma State University) Educational Resources for Pulsars and Gamma-ray Bursts 5. Q&A 3 Supernovae, GRBs and Swift Dr. Bethany Cobb Kung 4 Stellar Balance: Gravity vs. Pressure • Hydrogen fusion energy/heat pressure • Stellar mass gravity • In hydrostatic equilibrium, gravity = pressure (Image: NASA/SDO) (Illustration: NASA/CXC/M.Weiss) 5 “Core Collapse” Supernovae • ≳ 8 Solar Masses • Iron doesn’t fuse, so gravity “wins” SN 1987a • Implosion rebound supernova (Image: David Malin, Anglo-Australian Observatory) (Illustration: A. C. Phillips, The Physics of Stars, 2nd Edition) Cassiopeia A, SN remnant (Image: NASA/CXC/MIT/UMass Amherst/M.D.Stage et al.) 6 Supernovae Stellar Remnants Neutron Star or Black Hole • Mass ~ 2 Solar Masses • Mass > 3 Solar Masses • Radius ~ 10 km • Radius = 3 km × Mass (Illustration: NASA's Goddard Space Flight Center) (Illustration: Alain Riazuelo) 7 Gamma Ray Bursts (GRBs) • Some GRB are “super” supernovae or hypernovae (other GRBs are caused by neutron stars colliding) • Death of stars originally maybe 20 – 50 Solar Masses • Incredibly energetic: 1048 – 1052 ergs (released in only a few seconds) more energy than the Sun produces in its entire 10 billion year lifetime! • Visible from incredibly large distances (up to 13 billion lightyears, from when the universe was only about half a billion years old) 8 (Illustration: NASA's Goddard Space Flight Center) Gamma Ray Burst Jet Structure (Illustration: NASA's Goddard Space Flight Center) 9 Neil Gehrels Swift Observatory (Illustration: NASA's Goddard Space Flight Center and 2MASS/J. Carpenter, T. H. Jarrett, and R. Hurt) 10 Swift GRB Localization Gamma-rays X-rays Optical ~ a few arcminutes ~ a few arcseconds < 1 arcsecond (full Moon = 30 arcminutes) (Illustration: NASA) 11 GRB Optical Afterglow Precise localizations from Swift allow ground-based follow-up work GRB afterglows = transient X-ray/Optical/Radio sources Fade away rapidly (timescales of minutes to hours) DSS “before” image Observed by the SMARTS 1.3m telescope at CTIO in Chile (pre-burst) GRB 050730 ~ 3 hrs ~ 28 hrs ~ 10 days 12 Multi-telescope/Multi-wavelength GRB Observations = PHYSICS! (Credit: NASA/GSFC) 13 Gravity & Light from Merging Neutron Stars Dr. Elizabeth C. Ferrara 14 Supernovae Explode In as well as Out 15 Supernovae Explode In as well as Out 16 Supernovae Explode In as well as Out 17 Mass Determines Final State ? 18 Mass Determines Final State White Dwarf ? 19 Mass Determines Final State White Dwarf ? Black Hole 20 Mass Determines Final State White Dwarf Neutron ? Star Black Hole 21 Mass Determines Final State Mass Size White Dwarf Low Large Neutron ? Star Black Hole High Small 22 Binary Stars can be More Complicated 23 Binary Stars can be More Complicated 24 Eventually both stars evolve into Remnants Neutron Star Normal Star 25 Eventually both stars evolve into Remnants Neutron Star Normal Star 26 August 17, 2017 was a Very Special Day Play video: Fermi_GRB_1 (Sound On, please) 27 August 17, 2017 was a Very Special Day 28 29 30 So, What Happened Next? NGC 4993 31 So, What Happened Next? NGC 4993 32 33 3434 3535 Discovery Drives Understanding 36 Putting it all together Play video: Fermi_GRB_2 (No Sound, please) 37 We are All (Neutron Star) Stuff Thank You 38 Educational Resources for Pulsars and Gamma-ray Bursts Prof. Lynn Cominsky Sonoma State University 39 Neil Gehrels Swift Observatory • Launched November 21, 2004 • Three instruments: – Burst Alert Telescope (BAT) – Ultraviolet/Optical Telescope (UVOT) – X-ray Telescope (XRT) • Studies Gamma-Ray Bursts with a swift response – usually within ~1 minute http://swift.gsfc.nasa.gov 40 Gamma-ray Burst Educator Guide Includes: • Background Information • Activity 1 – Sorting out the Cosmic Zoo • Activity 2 – Angling for GRBs • Activity 3 – GRB Distribution on the Sky: The Plots Thicken • Activity 4 – Beam Me Hard copies of guide and poster available! Up! Send email to [email protected] 41 SortingSorting Out Out the the Cosmic Cosmic Zoo Zoo • Not everything that makes blastsAre these of X-rays the and gamma-rays is a GRB! same type of • This classification activity mimicsastrophysical the historical process that scientistsphenomenon? used to sort out events that appear similar at first glance Explain your reasoning by citing observational evidence. 42 Fermi Gamma-ray Space Telescope • Launched June 11, 2008 • Studies gamma rays over a very wide energy range • Two different instruments: – Large Area Telescope – Gamma-ray Burst Monitor • http://fermi.gsfc.nasa.gov https://fermi.gsfc.nasa.gov/fermi10/ 43 Fermi Pulsar Explorer https://fermi.gsfc.nasa.gov/science/pulsar5/ Interactive describing many pulsars seen with Fermi Large Area Telescope 44 Supernova Educator Guide Includes: • Background Information • Activity 1 - Fishing for Supernovae • Activity 2 - The Crawl of the Crab • Activity 3 - Magnetic Poles and Pulsars A. Seeing Magnetic Fields B. Make Your Own Pulsar C. Transfer Activity: Comparing the Earth to a Pulsar • Activity 4 - Neutron Stars in the News https://www.universe-of-learning.org/science- briefings/2017/7/21/cosmic-beacons 45 LIGO Educator Guide Includes: • Background Information • Activity 1 - Coalescing Black Holes • Activity 2 - Warping of Spacetime Multimedia products for LIGO/Virgo Observations of merging neutron star binary are here: https://www.ligo.org/detections /GW170817.php https://www.universe-of- learning.org/science- briefings/2017/10/25/multi-messenger- astronomy 46 LIGO FAQ for Kids 47 To ensure we meet the needs of the education community (you!), NASA’s UoL is committed to performing regular evaluations, to determine the effectiveness of Professional Learning opportunities like the Science Briefings. If you prefer not to participate in the evaluation process, you can opt out by contacting Kay Ferrari <[email protected]>. This product is based upon work supported by NASA under award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Jet Propulsion Laboratory, Smithsonian Astrophysical Observatory, and Sonoma State University. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration. 48.