From Color–Magnitude Diagram and Hertzsprung–Russell Diagram: Mapping the bibliometric trajectory of stellar evolution diagrams

The Color–Magnitude Diagram (CMD) and the Hertzsprung–Russell Diagram (HRD) have historically functioned as essential instruments for illustrating stellar evolution. This work presents a two-phase bibliometric analysis to delineate the research trajectories of these pictures in astronomical literature. In the initial phase, we have carried out with the results of CMD-related papers obtained from the Scopus database, exclusively using Q1-ranked journal articles to guarantee high academic rigor. Through the analysis of co-authorship networks, keyword co-occurrence mapping and temporal citation patterns, we delineate fundamental research clusters, prominent contributors and emerging themes in CMD-related studies. The second phase entails a comparative bibliometric assessment of HR diagram literature, ensuring alignment of analytical parameters for consistency. The comparison highlights considerable thematic similarities and differences in discipline emphasis, author connections and research activity. This dual-lens methodology elucidates the developing epistemological functions of CMD and HRD while providing insights into their separate impacts on the wider domain of stellar astrophysics.