test 3a - The stellar birthline is A The luminosities and...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
A. The luminosities and temperatures at which protostars first become visible as cool, luminous stellar objects Which of the following would likely trigger star formation Supernovae If a star begins on the main sequence with a chemical composition of (X,Y,Z)=(0.74, 0.24, 0.02), what will be the composition in the core at the end of helium burning? (0, 0, 0.02) 0, 0, 1 Which of the following best describes a Type Ia supernova? Explosion of a white dwarf. The spectra of emission nebulae contain mainly: Emission lines. What is the source of pressure in a white dwarf that successfully resists the force of gravity? Electrons that have become incompressible (degenerate). Order the sequence of nuclear burning phases of a 15 solar mass star where C = carbon burning, Fe = iron burning, H = hydrogen burning, He = helium burning, O = oxygen burning, N = nitrogen burning, Ne = neon burning, and Si = silicon burning. Some phases may be missing in the sequence. C. H,He,C,O,Si. ….. How does general relativity describe the force of gravity? As due to a curvature of space How were the heaviest elements in the universe formed? By core nuclear burning in massive stars The interstellar medium is kept at a million kelvins by Ionizing radiation from hot O and B stars . .supernovae explosions A typical size for a NS is 30 km The HR diagram shows evolutionary tracks of protostars (dashed lines) of different massas. Dots and numbers designate positions on the tracks; lower case letters identify several lines. Some may correspond to something real and others may not. Which track corresponds to the least massive protostar:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This test prep was uploaded on 04/21/2008 for the course ASTRONOMY 102 taught by Professor Flowers during the Spring '06 term at Clemson.

Page1 / 4

test 3a - The stellar birthline is A The luminosities and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online