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.
(a) With few ticks, moose retain a brown coat; (b) at high numbers of ticks, moose self-groom, destr
A true albino squirrel. Note the pink eyes.
scanning electron micrograph showing an ovum (pink) released by the ovary at ovulation surrounded by
True Forget-Me-Not