astronomy

National Science Olympiad Astronomy Event 2013

Stellar Evolution and Type II Supernovas

Chandra X-Ray Education & Public Outreach Office Donna L Young, Lead Educator – donna@aavso.org

The American Association of Variable Star Observers AAVSO

ASTRONOMY, Division C

DESCRIPTION: Students will demonstrate an understanding of the basic concepts of mathematics and physics relating to stellar evolution and Type II supernova events.

A TEAM OF UP TO: 2 APPROXIMATE TIME: 50 minutes

THE COMPETITION: Each team is permitted to bring two laptops, or two 3-ring binders, or one laptop computer and one 3-ring binder (any size) containing information in any form from any source. The materials must be 3-hole punched and inserted into the rings (notebook sleeves are allowable). Each team member is permitted to bring a programmable calculator. No Internet access is allowed.

Using information which may include Hertzsprung-Russell diagrams, spectra, light curves, motions, cosmological distance equations and relationships, stellar magnitudes and classification, multi-wavelength images (X-ray, UV, optical, IR, radio), charts, graphs, animations and DS9 imaging analysis software, participants will be asked to complete activities which include the following:

Use all available information to determine answers relating to stellar evolution, including stellar nurseries and star formation, proto-stars, main sequence stars, Cepheid variables, semiregular variables, red supergiants, neutron stars, magnetars, pulsars, Wolf-Rayet stars, stellar mass black holes, x-ray binary systems, and Type II supernovas.

Use all available information, including Kepler’s laws, rotation and circular motion to determine answers relating to the orbital motions of binary and multiple star systems; use parallax, spectroscopic parallax, and the distance modulus to calculate distances to Cepheid variables.

Students should be knowledgeable about the properties and characteristics of the stages of stellar evolution listed above, including spectral features and chemical composition, luminosity, blackbody radiation, color index (B-V), and H-R diagram transitions.

Students will be asked to identify, know the location, be knowledgeable about, and/or answer questions relating to the three content areas outlined above for the following Objects: Cas A, IGR J17091, NGC 6888/WR 136, PSR J0108-1431, Cygnus X-1, SXP 1062, M1, Delta Cep,V838 Mon, α Orionis, SN 2010JL, NGC 3582, LHa115-N19, IC 1396, Antares, the rhoOphiuchi cloud complex

Deep Sky Objects:

A. Stellar Nurseries & Star Formation 1) rho Ophiuchi Cloud Complex 2) IC 1396 (Elephant’s Trunk Nebula) 3) NGC 3582 B. Stars 1) delta Cep – Cepheid variable star 2) α Orionis (Betelgeuse) – red supergiant 3) α Scorpii (Antares) – red supergiant 4) V838 Mon – red supergiant 5) NGC 6888/WR 136 (Crescent Nebula & Wolf-Rayet Star) C. Type II Supernova remnants/cores 1) Cas A 2) SXP 1062 3) M1 (Crab Nebula) 4) LHa115-N19 5) SN 2010JL 6) PSR J0108-1431 D. X-Ray Binaries 1) IGR J17091 2) Cygnus X-1

Stellar Nurseries & Star Formation – rho Ophiuchi Cloud Complex

Stellar Nurseries & Star Formation – IC 1396 (Elephant’s Trunk Nebula)

Stellar Nurseries & Star Formation – NGC 3582

Stars: Delta Cep (δ Cephei)

delta cepzeta 3.6

alpha 2.4

epsilon 4.2

iota 3.5

gamma 3.2

beta 3.2

δ Cephei – prototype of all Cepheid variable stars

Delta Cep (δ Cephei)

Cepheid Instability Strip

Variable Star Astronomy, Chapter 7, Page 10http://www.aavso.org/sites/default/files/Chapter7.pdf

Stars: α Orionis - Betelgeuse

Stars: α Scorpii – Antares

Stars: V838 Monocerotis

Wolf-Rayet Star WR136 & NGC 6888 (Crescent Nebula)

Wolf-Rayet Star WR 136 & NGC 6888 (Crescent Nebula)

Semiregular Variables:

Semiregular Variables

Type II Supernova: Cassiopeia A (Cas A)/ Neutron Star

Type II Supernova: SXP 1062/ Pulsar

Type II Supernova: M1 (The Crab Nebula)/ Pulsar

Type II Supernova: LHa115-N19

Type II Supernova: SN 2010JL

Type II Supernova: PSR J0108-1431/ Pulsar

X-Ray Binary: IGR J17091/ Black Hole

X-Ray Binary: Cygnus X-1/ Black Hole

Arcturus - K1

Procyon – F5

Sun – G2

Spectroscopy

Spectral Image

Spectral Plot

Spectral Image & Spectral Plot

Spectral Image& Spectral Plot

HydrogenBalmerLines

Spectral Image, Spectral Plot &BalmerLines

Spectral Image

HydrogenBalmer Lines

Fraunhofer Lines Ca, H, He

Spectral Plot

Summary of the Classification of Stars

SpectralClass

Temperature (oK) Strength of Balmer lines Other lines to look for

O 30,000 - 60,000 weak or not visible Ionized He (4540Å)

B 10,000 - 30,000 moderate

A 7,500 - 10,000 strong

F 6,000 - 7,500 weak Ionized Ca (3930Å, 3970Å) strong compared to neutral H (4340Å)

G 5,000 - 6,000 weak Ionized Ca (3930Å, 3970Å) strong compared to neutral H (4340Å)

K 3,500 - 5,000 weak or not visible Many lines, neutral Ca 4230 Å

M < 3,500 not visible Many lines

Astronomy Event2012 Image Sets:

Images of DSOsLight CurvesSpectraH-R Diagram

Blackbody Radiation

Stellar Radiation Laws: Planck’s Law Wien’s Law Stefan-Boltzmann’s Law

L = 4πR2σT4

Cosmological Distances

Cepheid Variables

Cepheid Variable Stars:

Period-Luminosity Relationship and The Distance Modulus Mv = m - 5log10 (r) 10

Msun -M* = 2.5 log L*/Lsun

Basic Equations and Relationships The Distance Modulus: M = m - 5log10 (r) 10Kepler’s 3rd Law: (MA + MB) = a3

p2

v = d ; a = v ; 2π a = vP ; Fc = mac ; ac = v2 = rω2

t t r

Small Angle Formula: D = αd 206,265

1 pc = 206,265 au = 3.26 ly = 3.08 x 1016m1° = 60 arcmin = 60´ ; 1´ = 60 arcsec = 60˝

Inverse Square Law: L = 1/r2

Circumference, Area, Surface Area, and Volume of a Sphere

chandra.harvard.eduhttp://soinc.org

aavso.org

apod.nasa.gov

Chandra.harvard.edu/edu/request.html

National Astronomy Event Supervisors:Donna L Young, Lead Educator – donna@aavso.orgTad Komacek – tkomacek@uchicago.edu

Rules clarifications: available at www.soinc.org under event information

Event Preparation:1. Read the Event Description for content and allowable resources.2. Use the Webinar and PowerPoint for an overview of the content topics and deep sky objects.3. Use the Astronomy Coaches Manuel as a guide to collect images and information for the 2013 competition. 4. Use the APOD, Chandra and AAVSO websites for images and content.5. Download the 2012 Astronomy Event from the AAVSO website to use as a guide for types of questions and practice.

Astronomy Event Description for 2014 Stellar Evolution & Variable Stars

From Astronomy 2012 Event: T Tauri, RR Lyrae, Miras, Type Ia Supernovas

From Astronomy 2013 Event: Cepheids, Semiregulars, Type II Supernovas, X-ray Binaries

Astronomy 2014 Event: Some of the above plus other types of variables related to stages of stellar evolution