Edwin Hubble’s 1923–1924 papers on Cepheids in Andromeda

Target entity: Edwin Hubble’s 1923–1924 papers on Cepheids in Andromeda
Context triple: [100-inch Hooker telescope, usedInPublication, Edwin Hubble’s 1923–1924 papers on Cepheids in Andromeda]

• A. Hubble–Humason galaxy redshift measurements
  The Hubble–Humason galaxy redshift measurements are a landmark set of observations that extended and refined Edwin Hubble’s work on the expanding universe by systematically measuring the redshifts of distant galaxies.
• B. “A New Method of Determining Distances to Galaxies”
  “A New Method of Determining Distances to Galaxies” is a scientific paper that presents an innovative technique for measuring the distances to external galaxies, contributing to more accurate extragalactic distance scaling in astronomy.
• C. Slipher galaxy redshift measurements
  Slipher galaxy redshift measurements are early 20th-century spectroscopic observations by Vesto Slipher that first revealed significant radial velocities of spiral nebulae, laying crucial groundwork for the discovery of the expanding universe.
• D. 1912 paper on periods of 25 Cepheid variables in the Small Magellanic Cloud
  The 1912 paper on periods of 25 Cepheid variables in the Small Magellanic Cloud is Henrietta Swan Leavitt’s landmark work that revealed the period–luminosity relationship of Cepheid variable stars, providing a crucial tool for measuring cosmic distances.
• E. A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae
  "A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae" is Edwin Hubble’s landmark 1929 paper that established the linear relationship between galaxies’ distances and their recessional velocities, providing the first strong evidence for the expanding universe.
• F. None of above. chosen
• G. Unsure - the case is ambiguous/there is not enough information to decide.

Target entity: Edwin Hubble’s 1923–1924 papers on Cepheids in Andromeda
Target entity description: Edwin Hubble’s 1923–1924 papers on Cepheids in Andromeda are landmark astronomical studies that demonstrated Andromeda is a separate galaxy beyond the Milky Way, fundamentally expanding the known scale of the universe.

• A. Hubble–Humason galaxy redshift measurements
  The Hubble–Humason galaxy redshift measurements are a landmark set of observations that extended and refined Edwin Hubble’s work on the expanding universe by systematically measuring the redshifts of distant galaxies.
• B. “A New Method of Determining Distances to Galaxies”
  “A New Method of Determining Distances to Galaxies” is a scientific paper that presents an innovative technique for measuring the distances to external galaxies, contributing to more accurate extragalactic distance scaling in astronomy.
• C. Slipher galaxy redshift measurements
  Slipher galaxy redshift measurements are early 20th-century spectroscopic observations by Vesto Slipher that first revealed significant radial velocities of spiral nebulae, laying crucial groundwork for the discovery of the expanding universe.
• D. 1912 paper on periods of 25 Cepheid variables in the Small Magellanic Cloud
  The 1912 paper on periods of 25 Cepheid variables in the Small Magellanic Cloud is Henrietta Swan Leavitt’s landmark work that revealed the period–luminosity relationship of Cepheid variable stars, providing a crucial tool for measuring cosmic distances.
• E. A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae
  "A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae" is Edwin Hubble’s landmark 1929 paper that established the linear relationship between galaxies’ distances and their recessional velocities, providing the first strong evidence for the expanding universe.
• F. None of above. chosen