Introduction to nucleosynthesis in asymptotic giant branch stars
|
|
- Florence Parks
- 5 years ago
- Views:
Transcription
1 Introduction to nucleosynthesis in asymptotic giant branch stars Amanda Karakas 1 and John Lattanzio 2 1) Research School of Astronomy & Astrophysics Mt. Stromlo Observatory 2) School of Mathematical Sciences, Monash University
2 Lecture Outline 1. Introduction to AGB stars, and evolution prior to the AGB phase 2. Nucleosynthesis before the AGB phase 3. Evolution and nucleosynthesis of AGB stars 4. The slow-neutron capture process in AGB stars 5. Low and zero-metallicity AGB evolution 6. Super-AGB stars and post-agb objects
3 Outline of this lecture 1. Introduction to AGB stars 2. Observational constraints 3. Brief overview of stellar modelling techniques 4. Evolution of low and intermediate-mass stars up to the AGB phase
4 Useful Reference Texts Some of these can be viewed using Google books: 1. Chapter 2 from Asymptotic Giant Branch Stars, 2004, eds. H. J. Habing and H. Olofsson 2. D. D. Clayton, 1983, Principles of stellar evolution and nucleosynthesis 3. D. Arnett, 1996, Supernovae & Nucleosynthesis 4. B. E.J. Pagel, 1997, Stellar Nucleosynthesis and Chemical evolution of Galaxies 5. C. Iliadis, 2007, Nuclear Physics of Stars 6. M. Lugaro, 2004, Stardust from Meteorites 7. Available for download: Karakas (PhD thesis, 2003) and Simon Campbell (PhD thesis, 2007)
5 Where are they on a HR diagram? AGB stars
6 Introduction to AGB stars The asymptotic giant branch (AGB) phase is the final nuclear burning phase for all stars with masses 0.8 to 8Msun Brief! Lasts less than 1% of the main-sequence lifetime Cool (~3000 K) evolved red giants with distended envelopes (~ few hundred solar radii) Spectral types: M, MS, S, SC, C type Many AGB stars are observed to be losing mass rapidly (~10-5 Msun yr -1 ) through slow outflows (~10 km/s) A7er ejection of the envelope, the AGB phase is terminated leading to: AGB -> post-agb -> PN -> WD Various mixing episodes alter the surface composition Most are long-period variables (Mira, semi-regular, irregular) Recent reviews: Herwig (2005), van Winckel (2003)
7 Asymptotic Giant Branch stars H-rich envelope Mass scale: Total mass = 3Msun, Core mass = 0.6Msun Envelope mass = 2.4Msun Radial scale: If we scale the core to the size of a marble (few cms) then to reach the outer layers we have to travel ~ 500 metres! H-exhausted core
8 AGB stars From Frank Timmes website
9 A few definitions Low-mass stars: Initial masses from 0.8 to ~2.5 solar masses Intermediate-mass stars: Initial masses from ~2.5 to 8Msun These definitions for Z = 0.02; depend on Z Some authors define stars with M < 0.8 Msun as low-mass X = hydrogen mass fraction, Y = helium mass fraction, and Z = 1 - X - Y = metals In the Sun: X = 0.705, Y = 0.28, Z = [X/Y] = log 10 (X/Y) star - log 10 (X/Y) sun ; in our Sun [Fe/H] = 0.0 by definition
10 Birth statistics From Frank Timmes website
11 Stellar Lifetimes Age of the galaxy 1.2 x years; Universe 1.37 x years Initial mass (M sun ) Main sequence lifetime (Myr) x x x 10 4 Total stellar lifetime (Myr) x x x 10 5 From Woosley, Heger & Weaver (2002, Rev. Mod. Phys. 74, 1015) From my models (e.g. Karakas & Lattanzio 2007)
12 The origin of the elements Lower mass stars (< 0.8Msun) are still on the main sequence fusing hydrogen in their cores Hence these stars have not contributed to the chemical evolution of our Galaxy In terms of single stars, the most important are 1) massive stars that explode as Type II (core collapse) supernova, and 2) stars that evolve through the asymptotic giant branch (AGB) phase Relative lifetimes are different! SN are short-lived and contribute quickly (assumed instantaneously) AGB stars more slowly (50Myr to few Gyr)
13
14 Aims of these lectures AGB stars are important! So we need accurate observations of their physical properties (e.g. composition, masses, luminosities) Along with accurate stellar evolution models that can explain these properties Naturally there are problems with all of the above! In these set of lectures, I aim to teach you about the evolution and nucleosynthesis of AGB stars From the perspective of a stellar modeller Let s start with an overview of the observational data
15 Carbon-rich AGB stars Much of the information we have about the composition of AGB stars comes from their stellar spectra Carbon stars have strong bands of carbon compounds (e.g. CN, C 2, CH) and no metallic oxide bands, caused by C/O > 1 in the atmosphere Most C-rich stars are evolved giants First discovered by Secchi (1868) In 1952, Merrill discovered that Tc was present in the atmosphere of S-type stars (with enhanced C but C/O < 1) Review by Knapp & Wallerstein (1998)
16 Carbon-star spectra (from SDSS) A-type:blue 7,500 to 11,000K G-type:white/yelllow 5,000 to 6,000K M3-late type:red < 3,500K Carbon star:red < 3,500K
17 Carbon-star spectra (from SDSS) A-type:blue 7,500 to 11,000K G-type:white/yelllow 5,000 to 6,000K M3-late type:red < 3,500K Carbon star:red < 3,500K
18 AGB stars are long-period variables The M bol -log(p) diagram for LMC long-period variables (Wood 1998) Spectra of two variables. Upper is M-type and lower is C-type (Olivier & Wood 2003)
19 Presolar grains Graphite grain Murchison meteorite Silicon carbide grain
20 Silicon carbide (SiC) grains Not SN Low-mass AGB stars SN Type II Nova grains? From José et al. (2004)
21 Stellar modelling With these observational constraints in mind, we ll have a look at how we make models First, we model the interior structure That gives us the density, temperature as a function of the interior mass, at each time step Start with a zero-age main sequence model of the mass and composition we want By model, we mean a snapshot in time of a star in hydrostatic equilibrium The ZAMS model is evolved (or moved forward in time) by solving the stellar structure equations at each mass-mesh point within the star at each time step
22 1 solar mass ZAMS model 16 O 12 C 14 N
23 Then we evolve forward in time Modeller s view of an Hertzsprung-Russell diagram: show the change in effective temperatures and luminosity as a function of time t = 0
24 Stellar modelling Evolve from the main sequence to the AGB We include 6 species (H, 3,4 He, C, N and O) involved in the main energy-generating reactions AGB phase is computationally demanding: Prior to the AGB: max ~10,000 time-steps, avg ~ 2000 During the AGB: max ~1.2 million!, avg ~ 100,000 We stop the calculation when the envelope mass is lost Or, convergence difficulties cause the calculation to cease (more common!) Then this structure is used as input into a postprocessing nucleosynthesis code
25 Output from evolution code
26 Post-processing nucleosynthesis Require as input the structure of the star as a function of time This tells us how hot each burning region is, how extended the convective zones (in mass), how many mixing episodes Then, in the nucleosynthesis code we re-solve for the abundances in the star, as a function of interior mass and time For many isotopes (74 to ~200) Require as input the initial abundances and reaction rates We assume that the energy from these extra reactions does not change the structure of the star!
27 74 species nuclear network
28 Output from nucleosynthesis code Composition as function of mass at a given time-step:
29 Output from nucleosynthesis code Composition as function of mass at a given time-step: Composition at the surface, as as function of time
30 Output from nucleosynthesis code Composition as function of mass at a given time-step: By integrating the surface abundances over the star s lifetime, we get yields: Composition at the surface, as as function of time
31 Basic Stellar Evolution Prior to reaching the AGB, the stars evolve through core H and He-burning Main sequence: H to Helium τ ~ yrs for 1 ~ 10 8 yrs for 5 Red Giant Branch: core contracts outer layers expand E-AGB phase: a7er core He-burning star becomes a red giant for the second time
32 Core H-burning and beyond: 1Msun Movies from John Lattanzio s website:
33 Core H-burning and beyond: 5Msun
34 Evolution prior to the AGB phase A7er core H-burning has ceased, the envelope expands and the core begins to contract A hydrogen-shell burning is established in a shell around the contracting He-core This provides most of the surface luminosity At this point (owing to L = 4πσR 2 T eff 4 ) T eff drops owing to increasing L and R The envelope becomes convective, and moves inward into regions partially processed by previous H-burning (first dredge-up) Following a period of core He-burning, the star becomes a giant for the second time (AGB)
35 Core H-burning and beyond: 1Msun
36 Core H-burning and beyond: 1Msun
37 Core H-burning and beyond: 5Msun
38 The first dredge-up: 1Msun
39 The first dredge-up: 5Msun
40 Core helium ignition: m < 2.5 As stars ascend the giant branch, the He core continues to contract and heat Once the temperature inside the core reaches about 10 8 K, core He ignition takes place Low-mass stars need to contract substantially before reaching this temperature, causing the central regions to become electron-degenerate Neutrino energy losses from the core cause the temperature maximum to move outward Eventually, the triple alpha reactions are ignited at the point of maximum temperature E.O.S only slightly dependent on T, leading to a thermonuclear runaway: The core He flash
41 Core He-flash
42 Core He-flash
43 Core helium burning Will be discussed in more detail in Lecture 2 Following core He-ignition, there is a stable period of core helium fusion The coulomb repulsion is larger for He than for H, hence more energy is required to fusion to occur This means higher burning temperatures and because energy generation T 40, shorter lifetimes! Typical He-burning lifetimes are ~100 million years for low-mass stars (~1Msun), compared to for H-burning Whereas core He-burning lasts about 20 million years for the 5Msun, compared to 80 million years for H-burning
44 Structure during second dredge-up Results for a 5 Msun, Z = 0.02 model:
45 The second dredge-up: 5Msun
46 Summary of 1 st lecture All stars with masses ~0.8 to 8 Msun will pass through the AGB phase This phase is brief, lasting less than 1% of the main sequence lifetime The richest nucleosynthesis occurs there Observational constraints come from observations of stars and from meteorites data AGB phase is computationally demanding Low and intermediate-mass stars go through central H and He-burning before reaching the AGB Experience the first and/or second dredge-up which alters their surface composition
Evolution and nucleosynthesis prior to the AGB phase
Evolution and nucleosynthesis prior to the AGB phase Amanda Karakas Research School of Astronomy & Astrophysics Mount Stromlo Observatory Lecture Outline 1. Introduction to AGB stars, and the evolution
More informationEvolution and nucleosynthesis of AGB stars
Evolution and nucleosynthesis of AGB stars Amanda Karakas Research School of Astronomy & Astrophysics Mount Stromlo Observatory Lecture Outline 1. Introduction to AGB stars; evolution prior to the AGB
More informationLecture 7: Stellar evolution I: Low-mass stars
Lecture 7: Stellar evolution I: Low-mass stars Senior Astrophysics 2018-03-21 Senior Astrophysics Lecture 7: Stellar evolution I: Low-mass stars 2018-03-21 1 / 37 Outline 1 Scaling relations 2 Stellar
More informationPre Main-Sequence Evolution
Stellar Astrophysics: Stellar Evolution Pre Main-Sequence Evolution The free-fall time scale is describing the collapse of the (spherical) cloud to a protostar 1/2 3 π t ff = 32 G ρ With the formation
More informationHR Diagram, Star Clusters, and Stellar Evolution
Ay 1 Lecture 9 M7 ESO HR Diagram, Star Clusters, and Stellar Evolution 9.1 The HR Diagram Stellar Spectral Types Temperature L T Y The Hertzsprung-Russel (HR) Diagram It is a plot of stellar luminosity
More informationLife and Death of a Star. Chapters 20 and 21
Life and Death of a Star Chapters 20 and 21 90 % of a stars life Most stars spend most of their lives on the main sequence. A star like the Sun, for example, after spending a few tens of millions of years
More informationLifespan on the main sequence. Lecture 9: Post-main sequence evolution of stars. Evolution on the main sequence. Evolution after the main sequence
Lecture 9: Post-main sequence evolution of stars Lifetime on the main sequence Shell burning and the red giant phase Helium burning - the horizontal branch and the asymptotic giant branch The death of
More informationIntroductory Astrophysics A113. Death of Stars. Relation between the mass of a star and its death White dwarfs and supernovae Enrichment of the ISM
Goals: Death of Stars Relation between the mass of a star and its death White dwarfs and supernovae Enrichment of the ISM Low Mass Stars (M
More informationEvolution of Intermediate-Mass Stars
Evolution of Intermediate-Mass Stars General properties: mass range: 2.5 < M/M < 8 early evolution differs from M/M < 1.3 stars; for 1.3 < M/M < 2.5 properties of both mass ranges MS: convective core and
More informationAGB stars as laboratories for nuclear physics
AGB stars as laboratories for nuclear physics John Lattanzio with Amanda Karakas 1, Lisa Elliott, Simon Campbell, Maria Lugaro 2, Carolyn Doherty Centre for Stellar and Planetary Astrophysics, Monash University,Australia
More informationLecture 24: Testing Stellar Evolution Readings: 20-6, 21-3, 21-4
Lecture 24: Testing Stellar Evolution Readings: 20-6, 21-3, 21-4 Key Ideas HR Diagrams of Star Clusters Ages from the Main Sequence Turn-off Open Clusters Young clusters of ~1000 stars Blue Main-Sequence
More informationLecture 8: Stellar evolution II: Massive stars
Lecture 8: Stellar evolution II: Massive stars Senior Astrophysics 2018-03-27 Senior Astrophysics Lecture 8: Stellar evolution II: Massive stars 2018-03-27 1 / 29 Outline 1 Stellar models 2 Convection
More informationGuiding Questions. The Deaths of Stars. Pathways of Stellar Evolution GOOD TO KNOW. Low-mass stars go through two distinct red-giant stages
The Deaths of Stars 1 Guiding Questions 1. What kinds of nuclear reactions occur within a star like the Sun as it ages? 2. Where did the carbon atoms in our bodies come from? 3. What is a planetary nebula,
More informationThe Deaths of Stars 1
The Deaths of Stars 1 Guiding Questions 1. What kinds of nuclear reactions occur within a star like the Sun as it ages? 2. Where did the carbon atoms in our bodies come from? 3. What is a planetary nebula,
More informationChapter 19: The Evolution of Stars
Chapter 19: The Evolution of Stars Why do stars evolve? (change from one state to another) Energy Generation fusion requires fuel, fuel is depleted [fig 19.2] at higher temperatures, other nuclear process
More informationStellar Evolution: The Deaths of Stars. Guiding Questions. Pathways of Stellar Evolution. Chapter Twenty-Two
Stellar Evolution: The Deaths of Stars Chapter Twenty-Two Guiding Questions 1. What kinds of nuclear reactions occur within a star like the Sun as it ages? 2. Where did the carbon atoms in our bodies come
More informationThe Evolution of Low Mass Stars
The Evolution of Low Mass Stars Key Ideas: Low Mass = M < 4 M sun Stages of Evolution of a Low Mass star: Main Sequence star star star Asymptotic Giant Branch star Planetary Nebula phase White Dwarf star
More informationGuiding Questions. The Deaths of Stars. Pathways of Stellar Evolution GOOD TO KNOW. Low-mass stars go through two distinct red-giant stages
The Deaths of Stars Guiding Questions 1. What kinds of nuclear reactions occur within a star like the Sun as it ages? 2. Where did the carbon atoms in our bodies come from? 3. What is a planetary nebula,
More informationOxygen in AGB stars and the relevance of planetary nebulae to mapping oxygen in the Universe
Oxygen in AGB stars and the relevance of planetary nebulae to mapping oxygen in the Universe Amanda Karakas Research School of Astronomy & Astrophysics Mount Stromlo Observatory, Australia Introduction
More informationStellar Evolution Stars spend most of their lives on the main sequence. Evidence: 90% of observable stars are main-sequence stars.
Stellar Evolution Stars spend most of their lives on the main sequence. Evidence: 90% of observable stars are main-sequence stars. Stellar evolution during the main-sequence life-time, and during the post-main-sequence
More informationASTR-1020: Astronomy II Course Lecture Notes Section VI
ASTR-1020: Astronomy II Course Lecture Notes Section VI Dr. Donald G. Luttermoser East Tennessee State University Edition 4.0 Abstract These class notes are designed for use of the instructor and students
More informationLecture 16: The life of a low-mass star. Astronomy 111 Monday October 23, 2017
Lecture 16: The life of a low-mass star Astronomy 111 Monday October 23, 2017 Reminders Online homework #8 due Monday at 3pm Exam #2: Monday, 6 November 2017 The Main Sequence ASTR111 Lecture 16 Main sequence
More informationCHAPTER 11 LATE EVOLUTION OF M< 8 MSUN
CHAPTER 11 LATE EVOLUTION OF M< 8 MSUN SUMMARY M> 2 SOL AR MASSES H-rich He-rich SUMMARY M> 2 SOL AR MASSES 1) evolution on thermal timescale from ~C to E: very fast : ~105-6 yr ``Hertzspung gap in H-R
More informationStars and their properties: (Chapters 11 and 12)
Stars and their properties: (Chapters 11 and 12) To classify stars we determine the following properties for stars: 1. Distance : Needed to determine how much energy stars produce and radiate away by using
More informationEvolution Beyond the Red Giants
Evolution Beyond the Red Giants Interior Changes Sub-giant star 1 Post-Helium Burning What happens when there is a new core of non-burning C and O? 1. The core must contract, which increases the pressure
More informationThe life of a low-mass star. Astronomy 111
Lecture 16: The life of a low-mass star Astronomy 111 Main sequence membership For a star to be located on the Main Sequence in the H-R diagram: must fuse Hydrogen into Helium in its core. must be in a
More informationNucleosynthesis of Low and Intermediate-mass Stars
Nucleosynthesis of Low and Intermediate-mass Stars Amanda I. Karakas Research School of Astronomy & Astrophysics, Mount Stromlo Observatory, Weston Creek ACT 2611, Australia akarakas@mso.anu.edu.au Summary.
More informationStellar Evolution. Eta Carinae
Stellar Evolution Eta Carinae Evolution of Main Sequence Stars solar mass star: from: Markus Bottcher lecture notes, Ohio University Evolution off the Main Sequence: Expansion into a Red Giant Inner core
More informationChapter 12 Stellar Evolution
Chapter 12 Stellar Evolution Guidepost Stars form from the interstellar medium and reach stability fusing hydrogen in their cores. This chapter is about the long, stable middle age of stars on the main
More informationAST 101 Introduction to Astronomy: Stars & Galaxies
The H-R Diagram review So far: AST 101 Introduction to Astronomy: Stars & Galaxies - Stars on Main Sequence (MS) - Pre MS (Star Birth) Next: - Post MS: Giants, Super Giants, White dwarfs Evolution of Low
More informationCompton Lecture #4: Massive Stars and. Supernovae. Welcome! On the back table:
Compton Lecture #4: Massive Stars and Welcome! On the back table: Supernovae Lecture notes for today s s lecture Extra copies of last week s s are on the back table Sign-up sheets please fill one out only
More informationEinführung in die Astronomie II
Einführung in die Astronomie II Teil 10 Peter Hauschildt yeti@hs.uni-hamburg.de Hamburger Sternwarte Gojenbergsweg 112 21029 Hamburg 15. Juni 2017 1 / 47 Overview part 10 Death of stars AGB stars PNe SNe
More informationBefore proceeding to Chapter 20 More on Cluster H-R diagrams: The key to the chronology of our Galaxy Below are two important HR diagrams:
Before proceeding to Chapter 20 More on Cluster H-R diagrams: The key to the chronology of our Galaxy Below are two important HR diagrams: 1. The evolution of a number of stars all formed at the same time
More information10/17/2012. Stellar Evolution. Lecture 14. NGC 7635: The Bubble Nebula (APOD) Prelim Results. Mean = 75.7 Stdev = 14.7
1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 10/17/2012 Stellar Evolution Lecture 14 NGC 7635: The Bubble Nebula (APOD) Prelim Results 9 8 7 6 5 4 3 2 1 0 Mean = 75.7 Stdev = 14.7 1 Energy
More informationCh. 29 The Stars Stellar Evolution
Ch. 29 The Stars 29.3 Stellar Evolution Basic Structure of Stars Mass effects The more massive a star is, the greater the gravity pressing inward, and the hotter and more dense the star must be inside
More informationThe Later Evolution of Low Mass Stars (< 8 solar masses)
The Later Evolution of Low Mass Stars (< 8 solar masses) http://apod.nasa.gov/apod/astropix.html The sun - past and future central density also rises though average density decreases During 10 billion
More informationEvolution from the Main-Sequence
9 Evolution from the Main-Sequence Lecture 9 Evolution from the Main-Sequence P. Hily-Blant (Master PFN) Stellar structure and evolution 2016-17 111 / 159 9 Evolution from the Main-Sequence 1. Overview
More informationLate Stages of Stellar Evolution. Late Stages of Stellar Evolution
Late Stages of Stellar Evolution The star enters the Asymptotic Giant Branch with an active helium shell burning and an almost dormant hydrogen shell Again the stars size and luminosity increase, leading
More informationStellar Midlife. A. Main Sequence Lifetimes. (1b) Lifetime of Sun. Stellar Evolution Part II. A. Main Sequence Lifetimes. B. Giants and Supergiants
Stellar Evolution Part II 1 Stellar Midlife 2 Stellar Midlife A. Main Sequence Lifetimes B. Giants and Supergiants C. Variables (Cepheids) Dr. Bill Pezzaglia Updated Oct 9, 2006 A. Main Sequence Lifetimes
More informationNSCI 314 LIFE IN THE COSMOS
NSCI 314 LIFE IN THE COSMOS 2 BASIC ASTRONOMY, AND STARS AND THEIR EVOLUTION Dr. Karen Kolehmainen Department of Physics CSUSB COURSE WEBPAGE: http://physics.csusb.edu/~karen MOTIONS IN THE SOLAR SYSTEM
More informationChapter 17 Lecture. The Cosmic Perspective Seventh Edition. Star Stuff Pearson Education, Inc.
Chapter 17 Lecture The Cosmic Perspective Seventh Edition Star Stuff Star Stuff 17.1 Lives in the Balance Our goals for learning: How does a star's mass affect nuclear fusion? How does a star's mass affect
More informationAstronomy. Stellar Evolution
Astronomy A. Dayle Hancock adhancock@wm.edu Small 239 Office hours: MTWR 10-11am Stellar Evolution Main Sequence star changes during nuclear fusion What happens when the fuel runs out Old stars and second
More informationStellar Evolution and the HertzsprungRussell Diagram 7/14/09. Astronomy 101
Stellar Evolution and the HertzsprungRussell Diagram 7/14/09 Astronomy 101 Astronomy Picture of the Day Astronomy 101 Outline for Today Astronomy Picture of the Day News Articles Business Return Lab 5
More informationLecture 16: Evolution of Low-Mass Stars Readings: 21-1, 21-2, 22-1, 22-3 and 22-4
Lecture 16: Evolution of Low-Mass Stars Readings: 21-1, 21-2, 22-1, 22-3 and 22-4 For the protostar and pre-main-sequence phases, the process was the same for the high and low mass stars, and the main
More informationLow mass stars. Sequence Star Giant. Red. Planetary Nebula. White Dwarf. Interstellar Cloud. White Dwarf. Interstellar Cloud. Planetary Nebula.
Low mass stars Interstellar Cloud Main Sequence Star Red Giant Planetary Nebula White Dwarf Interstellar Cloud Main Sequence Star Red Giant Planetary Nebula White Dwarf Low mass stars Interstellar Cloud
More information20. Stellar Death. Interior of Old Low-Mass AGB Stars
20. Stellar Death Low-mass stars undergo three red-giant stages Dredge-ups bring material to the surface Low -mass stars die gently as planetary nebulae Low -mass stars end up as white dwarfs High-mass
More informationAstronomy 1504 Section 002 Astronomy 1514 Section 10 Midterm 2, Version 1 October 19, 2012
Astronomy 1504 Section 002 Astronomy 1514 Section 10 Midterm 2, Version 1 October 19, 2012 Choose the answer that best completes the question. Read each problem carefully and read through all the answers.
More informationStellar Structure and Evolution
Stellar Structure and Evolution Achim Weiss Max-Planck-Institut für Astrophysik 01/2014 Stellar Structure p.1 Stellar evolution overview 01/2014 Stellar Structure p.2 Mass ranges Evolution of stars with
More information7. The Evolution of Stars a schematic picture (Heavily inspired on Chapter 7 of Prialnik)
7. The Evolution of Stars a schematic picture (Heavily inspired on Chapter 7 of Prialnik) In the previous chapters we have seen that the timescale of stellar evolution is set by the (slow) rate of consumption
More informationAstronomy Ch. 20 Stellar Evolution. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Name: Period: Date: Astronomy Ch. 20 Stellar Evolution MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A star (no matter what its mass) spends
More informationAstronomy Ch. 20 Stellar Evolution. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Name: Period: Date: Astronomy Ch. 20 Stellar Evolution MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A star (no matter what its mass) spends
More informationTHE 82ND ARTHUR H. COMPTON LECTURE SERIES
THE 82ND ARTHUR H. COMPTON LECTURE SERIES by Dr. Manos Chatzopoulos Enrico Fermi Postdoctoral Fellow FLASH Center for Computational Science Department of Astronomy & Astrophysics University of Chicago
More informationReview: HR Diagram. Label A, B, C respectively
Stellar Evolution Review: HR Diagram Label A, B, C respectively A C B a) A: White dwarfs, B: Giants, C: Main sequence b) A: Main sequence, B: Giants, C: White dwarfs c) A: Main sequence, B: White Dwarfs,
More informationNuclear Physics and Astrophysics of Exploding Stars
Nuclear Physics and Astrophysics of Exploding Stars Lars Bildsten Kavli Institute for Theoretical Physics Department of Physics University of California, Santa Barbara Dan Kasen (UCSC), Kevin Moore (UCSB),
More informationGuiding Questions. Stellar Evolution. Stars Evolve. Interstellar Medium and Nebulae
Guiding Questions Stellar Evolution 1. Why do astronomers think that stars evolve? 2. What kind of matter exists in the spaces between the stars? 3. What steps are involved in forming a star like the Sun?
More informationStars IV Stellar Evolution
Stars IV Stellar Evolution Attendance Quiz Are you here today? Here! (a) yes (b) no (c) my views are evolving on the subject Today s Topics Stellar Evolution An alien visits Earth for a day A star s mass
More informationThe MonKey Project. An Update on Stellar Yields
The MonKey Project An Update on Stellar Yields Current State of the Art Yields The most boring part of stellar evolution? Or is it isochrone construction? Run lots of models and collect numbers Well its
More informationThe Monash Chemical Yields Project
The Monash Chemical Yields Project Carolyn Doherty (Konkoly Observatory) George Angelou Simon W. Campbell Ross Church Thomas Constantino Sergio Cristallo Pilar Gil Pons Amanda Karakas John Lattanzio Maria
More informationChapter 12 Stellar Evolution
Chapter 12 Stellar Evolution Guidepost This chapter is the heart of any discussion of astronomy. Previous chapters showed how astronomers make observations with telescopes and how they analyze their observations
More information7/9. What happens to a star depends almost completely on the mass of the star. Mass Categories: Low-Mass Stars 0.2 solar masses and less
7/9 What happens to a star depends almost completely on the mass of the star. Mass Categories: Low-Mass Stars 0.2 solar masses and less Medium-Mass Stars 0.2 solar masses up to between 2 and 3 solar masses.
More informationAstronomy 210. Outline. Stellar Properties. The Mosquito Dilemma. Solar Observing & HW9 due April 15 th Stardial 2 is available.
Astronomy 210 Outline This Class (Lecture 31): Stars: Spectra and the H-R Diagram Next Class: Life and Death of the Sun Solar Observing & HW9 due April 15 th Stardial 2 is available. The Mosquito dilemma
More informationUniverse. Chapter 19. Stellar Evolution: On and After the Main Sequence 8/13/2015. By reading this chapter, you will learn
Roger Freedman Robert Geller William Kaufmann III Universe Tenth Edition Chapter 19 Stellar Evolution: On and After the Main Sequence By reading this chapter, you will learn 19 1 How a main sequence star
More informationHigh Mass Stars. Dr Ken Rice. Discovering Astronomy G
High Mass Stars Dr Ken Rice High mass star formation High mass star formation is controversial! May form in the same way as low-mass stars Gravitational collapse in molecular clouds. May form via competitive
More informationRubidium, zirconium, and lithium production in massive AGB stars
Rubidium, zirconium, and lithium production in massive AGB stars Sterrekundig Instituut, University of Utrecht, Postbus 80000, 3508 TA Utrecht, The Netherlands E-mail: m.a.vanraai@students.uu.nl M. Lugaro
More informationBirth & Death of Stars
Birth & Death of Stars Objectives How are stars formed How do they die How do we measure this The Interstellar Medium (ISM) Vast clouds of gas & dust lie between stars Diffuse hydrogen clouds: dozens of
More information(2) low-mass stars: ideal-gas law, Kramer s opacity law, i.e. T THE STRUCTURE OF MAIN-SEQUENCE STARS (ZG: 16.2; CO 10.6, 13.
6.1 THE STUCTUE OF MAIN-SEQUENCE STAS (ZG: 16.2; CO 10.6, 13.1) main-sequence phase: hydrogen core burning phase zero-age main sequence (ZAMS): homogeneous composition Scaling relations for main-sequence
More informationLecture 24. Reprise: Evolution Timescale
Lecture 24 Life as a Low Mass Giant Dating the Stars Shell vs Core Fusion Helium Fusion Planetary Nebulae Mar 22, 2006 Astro 100 Lecture 24 1 Reprise: Evolution Timescale To estimate the duration of any
More informationAST 101 Introduction to Astronomy: Stars & Galaxies
AST 101 Introduction to Astronomy: Stars & Galaxies The H-R Diagram review So far: Stars on Main Sequence (MS) Next: - Pre MS (Star Birth) - Post MS: Giants, Super Giants, White dwarfs Star Birth We start
More informationThe physics of stars. A star begins simply as a roughly spherical ball of (mostly) hydrogen gas, responding only to gravity and it s own pressure.
Lecture 4 Stars The physics of stars A star begins simply as a roughly spherical ball of (mostly) hydrogen gas, responding only to gravity and it s own pressure. X-ray ultraviolet infrared radio To understand
More informationChapters 12 and 13 Review: The Life Cycle and Death of Stars. How are stars born, and how do they die? 4/1/2009 Habbal Astro Lecture 27 1
Chapters 12 and 13 Review: The Life Cycle and Death of Stars How are stars born, and how do they die? 4/1/2009 Habbal Astro 110-01 Lecture 27 1 Stars are born in molecular clouds Clouds are very cold:
More informationLife of a High-Mass Stars
Life of a High-Mass Stars 1 Evolutionary Tracks Paths of high-mass stars on the HR Diagram are different from those of low-mass stars. Once these stars leave the main sequence, they quickly grow in size
More informationA Star Becomes a Star
A Star Becomes a Star October 28, 2002 1) Stellar lifetime 2) Red Giant 3) White Dwarf 4) Supernova 5) More massive stars Review Solar winds/sunspots Gases and Dust Molecular clouds Protostars/Birth of
More informationThe Later Evolution of Low Mass Stars (< 8 solar masses)
The sun - past and future The Later Evolution of Low Mass Stars (< 8 solar masses) During 10 billion years the suns luminosity changes only by about a factor of two. After that though, changes become rapid
More informationLecture 44: The Future of Life in the Solar System
Lecture 44 The Future of Life in the Solar System Astronomy 141 Autumn 2009 This lecture is about the future of life in the Solar System. The Sun today is a steadily shining, middle-aged Main Sequence
More informationOutline - March 18, H-R Diagram Review. Protostar to Main Sequence Star. Midterm Exam #2 Tuesday, March 23
Midterm Exam #2 Tuesday, March 23 Outline - March 18, 2010 Closed book Will cover Lecture 8 (Special Relativity) through Lecture 14 (Star Formation) only If a topic is in the book, but was not covered
More informationStars: Their Life and Afterlife
The 68 th Compton Lecture Series Stars: Their Life and Afterlife Lecture 3: The Life and Times of Low Mass Stars Brian Humensky, lecturer http://kicp.uchicago.edu/~humensky/comptonlectures.htm October
More informationASTRONOMY 1 EXAM 3 a Name
ASTRONOMY 1 EXAM 3 a Name Identify Terms - Matching (20 @ 1 point each = 20 pts.) Multiple Choice (25 @ 2 points each = 50 pts.) Essays (choose 3 of 4 @ 10 points each = 30 pt 1.Luminosity D 8.White dwarf
More information5) What spectral type of star that is still around formed longest ago? 5) A) F B) A C) M D) K E) O
HW2 Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The polarization of light passing though the dust grains shows that: 1) A) the dust grains
More informationReading and Announcements. Read Chapter 14.1, 14.2 Homework #6 due Tuesday, March 26 Exam #2, Thursday, March 28
Reading and Announcements Read Chapter 14.1, 14.2 Homework #6 due Tuesday, March 26 Exam #2, Thursday, March 28 The life of the Sun The Sun started as a cloud of gas. Gravity caused the cloud to collapse.
More informationPlanetary Nebulae White dwarfs
Life of a Low-Mass Star AST 101 Introduction to Astronomy: Stars & Galaxies Planetary Nebulae White dwarfs REVIEW END STATE: PLANETARY NEBULA + WHITE DWARF WHAS IS A WHITE DWARF? Exposed core of a low-mass
More informationChapter 12 Review. 2) About 90% of the star's total life is spent on the main sequence. 2)
Chapter 12 Review TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 1) As a main-sequence star, the Sun's hydrogen supply should last about 10 billion years from the zero-age
More informationStellar Astronomy Sample Questions for Exam 4
Stellar Astronomy Sample Questions for Exam 4 Chapter 15 1. Emission nebulas emit light because a) they absorb high energy radiation (mostly UV) from nearby bright hot stars and re-emit it in visible wavelengths.
More informationStellar Evolution Notes
Name: Block: Stellar Evolution Notes Stars mature, grow old and die. The more massive a star is, the shorter its life will be. Our Sun will live about 10 billion years. It is already 5 billion years old,
More informationAstronomy II (ASTR1020) Exam 3 Test No. 3D
Astronomy II (ASTR1020) Exam 3 Test No. 3D 23 October 2001 The answers of this multiple choice exam are to be indicated on the Scantron with a No. 2 pencil. Don t forget to write your name and the Test
More informationthe nature of the universe, galaxies, and stars can be determined by observations over time by using telescopes
the nature of the universe, galaxies, and stars can be determined by observations over time by using telescopes The spectral lines of stars tell us their approximate composition Remember last year in Physics?
More information17.1 Lives in the Balance. Our goals for learning: How does a star's mass affect nuclear fusion?
Stellar Evolution 17.1 Lives in the Balance Our goals for learning: How does a star's mass affect nuclear fusion? How does a star's mass affect nuclear fusion? Stellar Mass and Fusion The mass of a main-sequence
More information10/26/ Star Birth. Chapter 13: Star Stuff. How do stars form? Star-Forming Clouds. Mass of a Star-Forming Cloud. Gravity Versus Pressure
10/26/16 Lecture Outline 13.1 Star Birth Chapter 13: Star Stuff How do stars form? Our goals for learning: How do stars form? How massive are newborn stars? Star-Forming Clouds Stars form in dark clouds
More informationAstronomy 114. Lecture 20: Death of stars. Martin D. Weinberg. UMass/Astronomy Department
Astronomy 114 Lecture 20: Death of stars Martin D. Weinberg weinberg@astro.umass.edu UMass/Astronomy Department A114: Lecture 20 28 Mar 2007 Read: Ch. 22,23 Astronomy 114 1/19 Announcements PS#5 posted
More informationASTRONOMY 220C ADVANCED STAGES OF STELLAR EVOLUTION AND NUCLEOSYNTHESIS. Spring, This is a one quarter course dealing chiefly with:
This is a one quarter course dealing chiefly with: ASTRONOMY 220C ADVANCED STAGES OF STELLAR EVOLUTION AND NUCLEOSYNTHESIS Spring, 2015 http://www.ucolick.org/~woosley a) Nuclear astrophysics and the relevant
More informationA Zoo of Ancient Stellar Relics in our Galactic Halo
A Zoo of Ancient Stellar Relics in our Galactic Halo Simon W. Campbell1,2 1) GAA, Dept. Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya 2) CSPA, Australia (Centre for Stellar and Planetary
More informationAnnouncement: Quiz Friday, Oct 31
Announcement: Quiz Friday, Oct 31 What is the difference between the giant, horizontal, and asymptotic-giant branches? What is the Helium flash? Why can t high-mass stars support themselves in hydrostatic
More informationASTRONOMY 220C ADVANCED STAGES OF STELLAR EVOLUTION AND NUCLEOSYNTHESIS. Spring, 2013
ASTRONOMY 220C ADVANCED STAGES OF STELLAR EVOLUTION AND NUCLEOSYNTHESIS Spring, 2013 http://www.ucolick.org/~woosley This is a one quarter course dealing chiefly with: a) Nuclear astrophysics (and nuclear
More informationStars, Galaxies & the Universe Announcements. Stars, Galaxies & the Universe Lecture Outline. HW#7 due Friday by 5 pm! (available Tuesday)
Stars, Galaxies & the Universe Announcements HW#7 due Friday by 5 pm! (available Tuesday) Midterm Grades (points) posted today in ICON Exam #2 next week (Wednesday) Review sheet and study guide posted
More informationASTRONOMY QUIZ NUMBER 11
ASTRONOMY QUIZ NUMBER. Suppose you measure the parallax of a star and find 0. arsecond. The distance to this star is A) 0 light-years B) 0 parsecs C) 0. light-year D) 0. parsec 2. A star is moving toward
More informationStars with Mⵙ go through two Red Giant Stages
Astronomy A. Dayle Hancock adhancock@wm.edu Small 239 Office hours: MTWR 10-11am Death of Stars Nuclear reactions in small stars How stars disperse carbon How low mass stars die The nature of white dwarfs
More informationChapter 17: Stellar Evolution
Astr 2310 Thurs. Mar. 30, 2017 Today s Topics Chapter 17: Stellar Evolution Birth of Stars and Pre Main Sequence Evolution Evolution on and off the Main Sequence Solar Mass Stars Massive Stars Low Mass
More informationStellar structure and evolution
Stellar structure and evolution Ulrike Heiter Uppsala University July 2012, Nordic-Baltic Summer School Outline 1. The lives of stars Overview of stellar evolution 2. Physics of stellar evolution Stellar
More informationLife on the main sequence is characterized by the stable burning of hydrogen to helium under conditions of hydrostatic
Chapter 9 Red Giant Evolution Life on the main sequence is characterized by the stable burning of hydrogen to helium under conditions of hydrostatic equilibrium. While the star is on the main sequence
More informationStars. The composition of the star It s temperature It s lifespan
Stars Stars A star is a ball of different elements in the form of gases The elements and gases give off electromagnetic radiation (from nuclear fusion) in the form of light Scientists study the light coming
More informationProtostars evolve into main-sequence stars
Understanding how stars evolve requires both observation and ideas from physics The Lives of Stars Because stars shine by thermonuclear reactions, they have a finite life span That is, they fuse lighter
More information