Passage
In the early twentieth century, astronomer Henrietta Swan Leavitt made a groundbreaking discovery while analyzing photographic plates at the Harvard College Observatory. By studying Cepheid variable stars, she established that a star’s intrinsic luminosity is directly related to the period of its pulsations. This relationship became a vital tool, enabling astronomers to calculate the distance to far-off galaxies. Indeed, Edwin Hubble used Leavitt’s law to determine the distance to the Andromeda Nebula, showing that it lay far outside our own galaxy.
Given that all the choices are true, the writer wants to revise the bolded sentence to provide the most specific, concrete details that support the claim that Leavitt's discovery was essential in measuring the vast scale of the universe. Which choice best accomplishes this goal?
- AIndeed, Leavitt's discovery earned her wide acclaim from peers, and Magnus Gösta Mittag-Leffler even considered nominating her for a Nobel Prize in 1924, though she had unfortunately passed away by then.
- Indeed, Edwin Hubble used Leavitt's law to calculate that the Andromeda Nebula was 2.5 million light-years away, proving it was a separate galaxy rather than a local cloud of gas.Cevap
- CIndeed, Edwin Hubble used Leavitt's law to show that another galaxy was located extremely far away from the Milky Way.
- DIndeed, Edwin Hubble used Leavitt's law to determine that Andromeda was a separate galaxy; which lay millions of light-years beyond our own Milky Way.