A1 19 Star Death

High Mass and Binary System Stellar Evolution

LACC §: 22.1, 22.2, 23.5

• High Mass (>~10 Msolar) Stars

• Binary Systems

• Enrichment of the ISM

An attempt to answer the “big questions”: What is out there? Where did I come from?

1Thursday, April 29, 2010

HR Diagram

http://outreach.atnf.csiro.au/education/senior/astrophysics/stellarevolution_hrintro.html




http://abyss.uoregon.edu/~js/ast122/lectures/lec16.html

The stellar wind causes mass loss for AGB stars. This loss is around 10-4 solar masses per year, which means that in 10,000 years the typical star will dissolve, leaving the central, hot core (the central star in a planetary nebula).

Low and High Mass Evolution




High Mass Evolution


If the star is larger than 8 solar masses, then the core continues to heat. Carbon and oxygen fuse to form neon, then magnesium, then silicon. All forming into burning shells surrounding an iron ash core.

Text




http://www.williams.edu/astronomy/Course-Pages/111/

Images/SN/sn_explosion.gif

Type-IISupernova


http://www.williams.edu/astronomy/Course-Pages/111/Images/SN/sn_explosion.gif






http://cse.ssl.berkeley.edu/bmendez/ay10/2000/cycle/snII.html

Supernova 1987a


http://physics.uoregon.edu/~jimbrau/astr122/Notes/Exam3rev.html

http://physics.uoregon.edu/~jimbrau/astr122/Notes/Exam3rev.html

http://ircamera.as.arizona.edu/NatSci102/NatSci102/movies/suprnova.mpg

Type-II Supernova






http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/supernovae.htm

Supernova Light Curves


http://www.williams.edu/astronomy/Course-Pages/111/Images/SN/saul_sm.mpg




http://www.stsci.edu/~mutchler/images/clouds_ctio.jpg

Supernova 1987a

http://apod.nasa.gov/apod/ap020331.html










http://www.sflorg.com/spacenews/sn022207_02.html

Supernova 1987a




http://astro.unl.edu/classaction/stellarevolution.html



















http://antwrp.gsfc.nasa.gov/apod/ap060726.html

Novae and Type-Ia Supernovae





Novae and Type-Ia SupernovaeSpectacular explosions keep occurring in the binary star system named RS Ophiuchi. Every 20 years or so, the red giant star dumps enough hydrogen gas onto its companion white dwarf star to set off a brilliant thermonuclear explosion on the white dwarf's surface. At about 2,000 light years distant, the resulting nova explosions cause the RS Oph system to brighten up by a huge factor and become visible to the unaided eye. The red giant star is depicted on the right...while the white dwarf is at the center of the bright accretion disk on the left. As the stars orbit each other, a stream of gas moves from the giant star to the white dwarf. Astronomers speculate that at some time in the next 100,000 years, enough matter will have accumulated on the white dwarf to push it over the Chandrasekhar Limit, causing a much more powerful and final explosion known as a supernova.




http://en.wikipedia.org/wiki/RS_Oph

http://en.wikipedia.org/wiki/RS_Oph

http://en.wikipedia.org/wiki/Red_giant

http://en.wikipedia.org/wiki/Red_giant

http://periodic.lanl.gov/elements/1.html

http://periodic.lanl.gov/elements/1.html

http://www.cfo.doe.gov/me70/manhattan/proliferation.htm

http://www.cfo.doe.gov/me70/manhattan/proliferation.htm



http://chandra.harvard.edu/photo/cosmic_distance.html

http://chandra.harvard.edu/photo/cosmic_distance.html

http://en.wikipedia.org/wiki/Nova

http://en.wikipedia.org/wiki/Nova

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2001ApJ...558..323H

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2001ApJ...558..323H



http://news.bbc.co.uk/2/hi/science/nature/5204676.stm

http://news.bbc.co.uk/2/hi/science/nature/5204676.stm

http://www.aas.org/

http://www.aas.org/



http://en.wikipedia.org/wiki/Chandrasekhar_limit

http://en.wikipedia.org/wiki/Chandrasekhar_limit

http://en.wikipedia.org/wiki/Supernova#Type_Ia

http://en.wikipedia.org/wiki/Supernova#Type_Ia

http://www.ifa.hawaii.edu/~barnes/ast110_06/tooe/1314a.jpg

Type Ia and Type II Supernovae




http://physics.uoregon.edu/~jimbrau/BrauImNew/Chap21/FG21_08.jpg

Type-I vs. Type-II Supernovae




http://www.redorbit.com/

education/reference_library/

universe/stellar_evolution/246/

index.html

Stellar Evolution:Low vs. High Mass

[Nova]


http://www.redorbit.com/education/reference_library/universe/stellar_evolution/246/index.html














Enrichment of the ISM

http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/supernovae.htm

the iron core collapses in just a few seconds to a neutron star (or black hole).

when the stellar core becomes solid iron, there is no fusion reaction available to produce energy to keep the core hot and maintain the pressure that resists gravity


http://www.scienceinschool.org

http://www.scienceinschool.org

Enrichment of the Interstellar Medium

Gas is recycled in the Galaxy. It goes into forming stars and is returned during the death throws of stars enriched with heavy elements for the next generation of stars. It is a giant cycle of life.

http://cse.ssl.berkeley.edu/bmendez/ay10/2002/notes/lec16.html




High Mass and Binary System Stellar Evolution

LACC §: 22.1, 22.2, 23.5• High Mass (>~10 Msolar) Stars: fuse all the way

up to Fe, iron; Type-II Supernovae (sometimes Gamma-Ray Bursters) fuse past Fe, iron

• Binary Systems: Novae, Type-Ia Supernovae, X-ray Binaries, X-ray Bursters)

• Enrichment of the ISM: Stars convert H into elements up to Fe: He, C, O, Ne, Mg, Si, Fe; Supernovae create elements heavier than Fe



LACC HW: Franknoi, Morrison, and Wolff, Voyages Through the Universe,

3rd ed.

• Ch. 22, pp. 509-511: 8 (Specifically, what is the cause of each: Nova, Type Ia Supernova, Type II Supernova)

Due first class period of the next week (unless there is a test this week, in which case it’s due

before the test).

AstroTeams, be working on your Distance Ladders


Stellar RemnantsLACC §: 22.1, 22.2, 23.5

• White Dwarfs

• Neutron

• Black Holes



Stellar Remnants

http://www.maa.mhn.de/Scholar/Starlife/evolutnc.html

electron degeneracy pressureneutron degeneracy

pressure




http://ircamera.as.arizona.edu/NatSci102/lectures/whitedwrf.htm

About 15 km

About 10,000 km

White Dwarf: Mass-Radius Relationship




Stellar Remnants

http://astro.ucc.ie/research/intro/index.html

About 15 km

About 10,000 kmDensity: ~100,000,000 tons/cc

Density: ~0.5 tons/cc




Stellar Remnants: Black Hole

http://www.astro.cornell.edu/academics/courses/astro201/bh_structure.htm

Note that the Schwarzschild radius scales with the mass of the black hole. The Schwarzschild radius of a 1 solar mass

black hole is 3 x 105 cm [3 km, less than 2 miles].





Neutron Stars / PulsarsWhat a star becomes when it dies depends on the mass left when all possible nuclear fuels are exhausted and the star has lost some of its original mass by ejecting it:

M <= 1.4 M -----> white dwarf (planetary nebulae)

1.4 M <M < ~3 M --> neutron stars/pulsars (type II supernova)

M > ~ 3 M ----> supernovae/black holes (type II supernova)

Pulsar Animation




http://www3.amherst.edu/~gsgreenstein/progs/animations/pulsar_beacon/

http://www3.amherst.edu/~gsgreenstein/progs/animations/pulsar_beacon/

http://hera.ph1.uni-koeln.de/%7Eheintzma/NS1/SN1054.htm

The Crab Nebula/Pulsars

This picture shows a time sequence for the pulsar in the Crab nebula, shown in context against an image.... Both the nebula and its central pulsar were created by a supernova explosion in the year 1054 A.D. The enlarged region is a mosaic of 33 time slices, ordered from top to bottom and from left to right. Each slice represents approximately one millisecond in the period of the pulsar.






What would a naked black hole look like? Maybe...

http://www.tutorgig.com/ed/black_hole

“A (simulated) Black Hole of ten solar masses as seen from a distance of 600 km with the Milky Way in the background (horizontal camera opening angle: 90°).”




http://www.spitzer.caltech.edu/Media/happenings/20050526/




http://www.daviddarling.info/encyclopedia/G/gamma-ray_burst.html

Gamma-Ray BurstsJames Annis, an astrophysicist at Fermilab, near Chicago, has speculated that such events could sterilize entire galaxies, wiping out life-forms before they had the chance to evolve to the stage of interstellar travel. 1 "If one went off in the Galactic center," he wrote, "we here two-thirds of the way out of the Galactic disk would be exposed over a few seconds to a wave of powerful gamma rays." It would be enough, according to Annis, to exterminate every species on Earth. Even the hemisphere shielded by the planet's mass from immediate exposure would not escape, he claimed, since there would be lethal indirect effects such as the demolition of the entire protective ozone layer. The rate of GRBs in the universe today appears to be about one burst per galaxy per several hundred million years.




http://www.daviddarling.info/encyclopedia/O/ozone.html

http://www.daviddarling.info/encyclopedia/O/ozone.html

http://www.roe.ac.uk/roe/support/pr/pressreleases/050608-ultracam/index.html

X-ray binaries & X-ray bursters




into it forming an even tighter binary system. The core of the massive star produces a supernova and leaves behind a neutron star. The neutron star's companion eventually begins to lose mass and forms an accretion disk around the neutron star. The accretion of material onto the neutron star causes it to spin faster and faster, eventually reaching a spin period of a few milliseconds. The accreted material produces X-rays which in turn can begin vaporizing the companion. All that remains at the end is a highly compact, rapidly rotating neutron star which produces a pair of radio beams and may be observable as a millisecond radio pulsar. http://heasarc.gsfc.nasa.gov/docs/

xte/Snazzy/Movies/millisecond.html

Millisecond PulsarsThis animation attempts to condense the billion year evolutionary history of such a binary system into a few tens of seconds. It begins with two stars, one more massive than the other, in a tight orbit. The massive star evolves first and swallows up its companion, which spirals


http://heasarc.gsfc.nasa.gov/docs/xte/Snazzy/Movies/millisecond.html




http://heasarc.gsfc.nasa.gov/docs/xte/Snazzy/Movies/millisecond.mov

http://heasarc.gsfc.nasa.gov/docs/xte/Snazzy/Movies/millisecond.mov

Stellar RemnantsLACC §: 22.1, 22.2, 23.5

• White Dwarfs (Chandrasekhar mass limit = 1.4 M☉): the dead carbon cores (<~1.4 M☉) of low mass stars (<~10 M☉) left behind after a Planetary Nebulae

• Neutron Stars and Pulsars: neutron degenerate remnants (1.4 < 3 M☉) of high mass stars (>~10 M☉) left behind after a Type-II Supernovae

• Black Holes (>3 M☉): ∞ dense remnants of high mass stars (>~10 M☉) after a Type-II Supernovae



LACC HW: Franknoi, Morrison, and Wolff, Voyages Through the Universe,

3rd ed.

• Ch. 23, p. 532: 4.

Due at the beginning of next class period.

Test covering chapters 14-23 next class period.


Review for Test (4 of 5): Stars[10 pts] The Sun

• proton-proton chain (hydrogen nucleus, proton, positron, gamma rays, helium nucleus), the neutrino problem

• interior → atmosphere: core, radiation zone, convection zone, photosphere, chromosphere, corona, solar wind

• solar phenomena (solar magnetic field): granules sunspots, flares, prominence/filaments, coronal mass ejection, aurora and geomagnetic storms (on Earth)

[10 pts] Stars • stellar spectra: temperature, spectral class, radial velocity

(red-shift vs. blue shift), composition, cluster age (main sequence turn-off)

• determining distances: (radar (closest planets/asteroids only)), stellar parallax, standard candles--e.g. main sequence fitting, RR Lyrae and Cepheid variables

• other properties: proper motion, luminosity, apparent brightness/magnitude vs. absolute brightness/magnitude, spectroscopic or eclipsing binaries to determine mass

[10 pts] Stellar Evolution• HR Diagram: x-,y-axes, evolutionary tracks• low mass evolution: Hayashi track, main sequence (H

core burning), red giant branch (H shell burning), helium flash (He core ignition), horizontal giant branch (He core burning), asymptotic giant branch (He shell burning), planetary nebulae (envelope ejection), white dwarf

• high mass evolution: similar to low mass stars, but keep fusing elements up to iron, type-II supernova (gamma ray burst), neutron star (pulsar) or black hole

[10 pts] Nebulae, Binary Systems & Stellar Remnants • nebulae: molecular clouds, HII regions (star forming

regions, planetary nebulae, supernova remnants), reflection nebulae, supernova remnants

• nova and type-I supernova: binary system with a white dwarf, light curves; X-ray binaries and X-ray bursters: binary system with a neutron star or black hole; accretion disks

• stellar remnants: masses, sizes, densities of white dwarfs vs. neutron star vs. black holes; pulsars; black holes (singularity, Schwarzschild radius, event horizon)

[10 pts] Identify from an Image or Chart• solar surface features: sun spots (umbra, penumbra),

granules, prominence, flare, coronal mass ejection; nebulae: molecular clouds, star forming HII region, planetary nebulae, reflection nebulae

• HR Diagram: regions--main sequence, white dwarfs, giants, supergiants, spectral class, luminosity class; axes--x-axis = temperature, spectral class; y-axis = luminosity, absolute magnitude; mass & age & main sequence--high mass at top left, short lifetimes; low mass at lower right, long lifetimes; main sequence turn-off point gives a star cluster’s age

• Make use of a chart containing the following stellar data: apparent magnitude (mv), absolute magnitude (Mv), spectral class, luminosity class


A1 19 Star Death

Education

Transcript of A1 19 Star Death