Study of 26 Galactic Open Clusters with Extended Main-sequence Turnoffs  

作　　者：Yang-Yang Deng Zhong-Mu Li 

机构地区：[1]Yunnan Observatories,Chinese Academy of Sciences,Kunming 650216,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Institute of Astronomy and Information,Dali University,Dali 671003,China

出　　处：《Research in Astronomy and Astrophysics》2024年第6期28-37,共10页天文和天体物理学研究（英文版）

基　　金：supported by Yunnan Academician Workstation of Wang Jingxiu(202005AF150025);China Manned Space Project(NO.CMSCSST-2021-A08);Guanghe project(ghfund202302019167);the Natural Science Foundation of Yunnan Province(No.202201BC070003)。

摘　　要：Recent studies indicate that some Galactic open clusters(OCs)exhibit extended main-sequence turnoff(eMSTO)in their color–magnitude diagrams(CMDs).However,the number of Galactic OCs with eMSTO structures detected so far is limited,and the reasons for their formation are still unclear.This work identifies 26 Galactic OCs with undiscovered eMSTOs and investigates the causes of these features.Stellar population types and fundamental parameters of cluster samples are acquired using CMD fitting methods.Among them,the results of 11 OCs are reliable as the observed CMDs are well-reproduced.We propose the crucial role of stellar binarity and confirm the importance of stellar rotation in reproducing eMSTO morphologies.The results also show that the impact of age spread is important,as it can adequately explain the structure of young OCs and fit the observed CMDs of intermediate-age OCs better.

关 键 词：(stars:)binaries:general Galaxy:fundamental parameters (Galaxy:)open clusters and associations:general (stars:)Hertzsprung Russell and C-M-diagrams 

分 类 号：P154[天文地球—天文学]