Which of the following statements about brown dwarfs is not true?
A) Brown dwarfs are supported against gravity by degeneracy pressure, which does not depend on the object's temperature.
B) Brown dwarfs eventually collapse to become white dwarfs.
C) All brown dwarfs have masses less than about 8 that of our Sun.
D) Brown dwarfs form like ordinary stars but are too small to sustain nuclear fusion in their cores.
Question 2
A star is seen to have two transiting planets. Planet 1 transits every 3 months, and Planet 2 transits every 15 months. What can we infer about their orbits? (Hint: Review the use of Newton's version of Kepler's Third law from Ch. 4)
A) Planet 2's semimajor axis is about 5 times smaller than Planet 1's.
B) Planet 2's semimajor axis is about 3 times smaller than Planet 1's.
C) Planet 2's semimajor axis is about 3 times larger than Planet 1's.
D) Planet 2's semimajor axis is about 5 times larger than Planet 1's.
Apparent and True Orbits of Alpha Centauri.
True-color image of layers of haze in Titan's atmosphere.
Dred Scott and his wife and children are featured on the cover of Frank Leslie’s Illustrated Newspap