Triple

Target class: Type II supernova
Context triple: [SN 1987A, instanceOf, Type II supernova]

• A. subgiant star
  A subgiant star is a stellar object that has exhausted hydrogen in its core and is transitioning off the main sequence, expanding and cooling as it begins to burn hydrogen in a surrounding shell.
• B. orange giant star
  An orange giant star is an evolved, moderately cool, and luminous star that has exhausted hydrogen in its core and expanded to a large radius, emitting a characteristic orange hue.
• C. neutron star property
  A neutron star property is a physical or observational characteristic—such as mass, radius, spin, magnetic field strength, or temperature—that quantifies and describes the state and behavior of a neutron star.
• D. gravitational collapse model
  A gravitational collapse model is a theoretical framework that describes how matter in astrophysical systems contracts under its own gravity, potentially leading to the formation of dense objects such as stars, black holes, or compact stellar remnants.
• E. astrophysical instability
  An astrophysical instability is a physical process in which small perturbations in an astronomical system grow over time, potentially leading to dramatic structural or dynamical changes such as star formation, disk fragmentation, or explosive events.
• F. None of above. chosen