first millisecond pulsar PSR B1937+21

Target entity: first millisecond pulsar PSR B1937+21
Context triple: [Arecibo Observatory, discovered, first millisecond pulsar PSR B1937+21]

• A. neutron star hypothesis
  The neutron star hypothesis is Fritz Zwicky’s pioneering proposal that supernova explosions leave behind extremely dense stellar remnants composed primarily of neutrons, now known as neutron stars.
• B. Baade’s star
  Baade’s star is a luminous, variable star in the Andromeda Galaxy notable for its role in Walter Baade’s work refining the cosmic distance scale.
• C. Tolman surface brightness test
  The Tolman surface brightness test is an observational cosmology method that checks whether the universe is expanding by examining how the surface brightness of distant galaxies diminishes with redshift.
• D. Oppenheimer–Volkoff limit
  The Oppenheimer–Volkoff limit is the theoretical maximum mass a neutron star can have before collapsing into a black hole under its own gravity.
• E. Cocconi
  Cocconi is an Italian surname most notably associated with physicist Giuseppe Cocconi, a pioneer in particle physics and early SETI research.
• F. None of above. chosen
• G. Unsure - the case is ambiguous/there is not enough information to decide.

Target entity: first millisecond pulsar PSR B1937+21
Target entity description: PSR B1937+21 is the first-discovered millisecond pulsar, a rapidly rotating neutron star that spins hundreds of times per second and serves as a key object in the study of extreme astrophysical environments and precise cosmic timing.

• A. neutron star hypothesis
  The neutron star hypothesis is Fritz Zwicky’s pioneering proposal that supernova explosions leave behind extremely dense stellar remnants composed primarily of neutrons, now known as neutron stars.
• B. Baade’s star
  Baade’s star is a luminous, variable star in the Andromeda Galaxy notable for its role in Walter Baade’s work refining the cosmic distance scale.
• C. Tolman surface brightness test
  The Tolman surface brightness test is an observational cosmology method that checks whether the universe is expanding by examining how the surface brightness of distant galaxies diminishes with redshift.
• D. Oppenheimer–Volkoff limit
  The Oppenheimer–Volkoff limit is the theoretical maximum mass a neutron star can have before collapsing into a black hole under its own gravity.
• E. Cocconi
  Cocconi is an Italian surname most notably associated with physicist Giuseppe Cocconi, a pioneer in particle physics and early SETI research.
• F. None of above. chosen