Star Formation

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Star Formation
2012-04-28 16:58:03
Astro1 Exam2

star formation
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  1. What condition is considered sufficient for an interstellar cloud to collapse andform a star or stars (i.e., if this condition holds then the cloud has to collapse)?
    Gravity must dominate gas pressure inside the cloud.
  2. The smallest mass that a main sequence star can have is about 0.08 solar mass.The reason for this is that
    the temperature in the core of a contracting protostar of less than 0.08 solarmasses does not get high enough for nuclear reactions to start.
  3. Which kind of nebula is heated by hot, young massive stars?
  4. The most likely places in which stars and planetary systems are forming in theuniverse are
    gas and dust nebulae.
  5. Protostars are objects
    that are slowly contracting and heating up.
  6. Dark Nebulae
    Raw material for star and planet formation
  7. Protostars
    collapsing clumps of gas on their way to becoming stars, which have not started nuclear fusion. Protostars are large cool and luminous.
  8. At what temperature does nuclear fusion start?
    10 million K.
  9. What is the interstellar medium
    the matter that exists in the space between the star systems in a galaxy. The space is not completely empty, contains huge clouds of gas and dust called nebulae.
  10. Dark nebulae are also known as?
    molecular clouds
  11. Emission Nebulae
    • Clouds of ionized gas surrounding hot, massive,
    • newborn stars.