How has the focus of astronomical discovery shifted regarding nebulae since the time of early catalogers?

Answer

From mere identification to deep physical characterization, including elements and timing of progenitor events.

Early catalogers focused on identifying objects that did not move like planets; modern discovery involves deep physical characterization, determining specific composition, element presence, and the timeline of the progenitor star's demise.

How has the focus of astronomical discovery shifted regarding nebulae since the time of early catalogers?
HistorydiscoverySpaceastronomynebulas