chapter 10 the death of stars part a n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Chapter 10: The Death of Stars ( part a ) PowerPoint Presentation
Download Presentation
Chapter 10: The Death of Stars ( part a )

Loading in 2 Seconds...

play fullscreen
1 / 37

Chapter 10: The Death of Stars ( part a ) - PowerPoint PPT Presentation


  • 159 Views
  • Uploaded on

Chapter 10: The Death of Stars ( part a ). The evolution of low-mass vs. that of high-mass stars. Planetary nebulae and the formation of white dwarf stars. Supernova explosions: two types Type I: due to “carbon detonation” of an accreting white dwarf in a binary.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Chapter 10: The Death of Stars ( part a )


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. Chapter 10: The Death of Stars (part a) The evolution of low-mass vs. that of high-mass stars. Planetary nebulae and the formation of white dwarf stars. Supernova explosions: two types Type I: due to “carbon detonation” of an accreting white dwarf in a binary. Type II: due to “core collapse” in a high-mass star. Both types of supernovae leave behind remnants. Evidence from clusters confirms our theories of stellar evolution. Compact objects: neutron stars, pulsars, quark stars, and black holes.

    2. In a young star on the main sequence, hydrogen shell burning occurs around an “ash” core, which is mostly helium. The core temperature is about T = 10 million K

    3. Stars with Masses between 0.08 and 0.4 times the mass of the Sun have low core temperatures, live a long time, convect helium from the core, so it mixes uniformly, and will end up composed entirely of helium.

    4. Stars with mass greater than 0.4 solar masses burn faster. During stage 7 hydrogen burning causes a build-up of helium in the star’s core.Eventually a core of helium “ash” accumulates in the core.On the next slide, we follow the evolution of a star like the Sun, with one solar mass.

    5. Helium shell burning continues, and carbonburning commences

    6. Examine each of these in detail on next 3 slides:

    7. Planetary Nebulae form when the core can’t reach 600 million K, the minimum needed for carbon burning.

    8. A Planetary Nebula shaped like a sphere, about 1.5 pc across. The white dwarf is in the center.

    9. A Planetary Nebula with the shape of a ring, 0.5 pc across, called the “Ring Nebula”.

    10. Cat’s Eye Nebula, 0.1 pc across, may be from a pair of binary stars that both shed envelopes.

    11. M2-9 has twin lobes leaving the central star at 300 km/sec, reaching 0.5 pc end-to-end.

    12. (See the slide show of planetary nebulae.) Many more examples of planetary nebulae are known: • NOAO: • http://www.noao.edu/outreach/aop/observers/pn.html • http://www.noao.edu/image_gallery/planetary_nebulae.html • AAO: http://www.aao.gov.au/images/general/planetary_frames.html • ESO:http://www.eso.org/gallery/v/ESOPIA • And for a list of the Messier Catalog, see the SEDS Messier database: (using a chart of icons here) http://seds.lpl.arizona.edu/messier/ ?link

    13. Sirius Binary System: Sirius B is a white dwarf

    14. White Dwarfformation on the H–R DiagramSome heavier elements are formed in the last years of the burning in the shells surrounding the carbon core. H, He, C, O, and some Ne and Mg are expelled from the star as a “planetary nebula”

    15. Sirius B has a high mass for a white dwarf, and probably came from a mass 4 Msolar star.

    16. Distant White Dwarfs in Globular cluster M4.

    17. A Nova is an explosion on a white dwarf, but only a small amount of material on the surface of the white dwarf explodes. Nova Herculis 1934a) in March 1935b) in May 1935, after brightening by a factor of 60,000

    18. Nova Persei - matter ejection seen 50 years after 1901 flash (brightened by factor of 40,000)

    19. Nova light curve – due to a nuclear flash on a white dwarf

    20. Artist’s drawing of a Close Binary System