Astronomy current events question: Gliese 581's super earth, part 2

Astronomy 10L, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events (skytonight.com, from Sky & Telescope magazine), and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

[0.2 points.] How was the recently discovered planet orbiting the red dwarf star Gliese 581 discovered? Circle your answer below.
(A) From the repetitive wobbles that the planet gravitationally exerts on Gliese 581.
(B) From the amount of light blocked by the planet as it passes in front of Gliese 581.
(C) From the amount of bright light emitted by the very hot planet, compared to the dim cool light emitted from Gliese 581.
(D) From deciphering ancient hieroglyphics in a newly discovered tomb in Egypt.
(E) From deciphering ancient glyphs from a previously overlooked Mayan codex.

Correct answer: (A).

Student responses
Section 4137
(A) : 13 students
(B) : 3 students
(C) : 5 students
(D) : 1 student
(E) : 0 students

Section 4138
(A) : 11 students
(B) : 5 students
(C) : 3 students
(D) : 0 students
(E) : 0 students

Section 4139
(A) : 10 students
(B) : 6 students
(C) : 1 student
(D) : 0 students
(E) : 0 students

Note that choices (A)-(C) are all used to find extrasolar planets. The one student who picked the nonsense choice (D) admitted to selecting it blindly at random.