Astronomy current events question: composition of SDSS J122859.93+104032.9 planet fragment

Astronomy 210L, spring semester 2019
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!)

Peter Thorley, "Heavy Metal Planet Fragment Survives Destruction From Dead Star" (April 4, 2019)
warwick.ac.uk/newsandevents/pressreleases/heavy_metal_planet/

A planet fragment may be composed of __________, based on surviving its orbit around white dwarf SDSS J122859.93+104032.9.
(A) plasma.
(B) dark matter.
(C) heavy metals.
(D) degenerate matter.
(E) hydrogen and helium.

Correct answer: (C)

Student responses
Sections 30679, 30680
(A) : 4 students
(B) : 0 students
(C) : 35 students
(D) : 2 students
(E) : 2 students