Astronomy current events question: black hole companion to star MWC 656

Astronomy 210L, spring semester 2014
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!)

Universitat de Barcelona news release, "Spanish Researchers Discover the First Black Hole Orbiting a 'Spinning' Star," January 16, 2014
http://www.ub.edu/web/ub/en/menu_eines/noticies/2014/01/015.html

Spanish scientists determined that star MWC 656 is orbited by a black hole, based on the fact that it is invisible to telescopes, and:
(A) no other surviving stars are nearby.
(B) rich in dark matter.
(C) the star MWC 656 is steadily losing mass.
(D) absorbs gamma-ray radiation.
(E) more massive than a neutron star.

Correct answer: (E)

Student responses
Sections 30678, 30679, 30680
(A) : 7 students
(B) : 8 students
(C) : 15 students
(D) : 19 students
(E) : 9 students