Astronomy current events question: brown dwarf 2MASS 2139 giant storm

Astronomy 210L, fall semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)

Ian O'Neill, "Violent Storms Rage on Nearby Brown Dwarf," September 13, 2011
http://news.discovery.com/space/violent-storms-rage-on-nearby-brown-dwarf-110913.html

A University of Toronto-led team of astronomers detected a possible gigantic storm on a brown dwarf by observing __________ over a short time span.
(A) lightning flashes.
(B) spacetime ripples.
(C) fluctuations in radio noise.
(D) infrared brightness variations.
(E) increasing color intensities.

Correct answer: (D)

Student responses
Sections 70178, 70186, 70200
(A) : 2 students
(B) : 1 student
(C) : 3 students
(D) : 30 students
(E) : 14 students