Gilligan, Christina K.Chaboyer, BrianCummings, Jeffrey D.Mackey, DougalCohen, Roger E.Geisler, DouglasGrocholski, Aaron J.Parisi, M. C.Sarajedini, AtaVentura, PaoloVillanova, SandroYang, Soung ChulWagner-Kaiser, Rachel2025-03-142025-03-14researchoutputwizard:u3102795xPUB3557Scopus:85068009953WOS:WOS:000474908200087https://dspace-test.anu.edu.au/handle/1885/733716145We present a multiple population search in two old Large Magellanic Cloud (LMC) Globular clusters, Hodge 11 and NGC 2210. This work uses data from the Advanced Camera for Surveys and Wide Field Camera 3 on the Hubble Space Telescope from programme GO- 14164 in Cycle 23. Both of these clusters exhibit a broadened main sequence with the second population representing (20±~5) per cent forNGC2210 and (30±~5) per cent forHodge 11. In both clusters, the smaller population is redder than the primary population, suggesting CNO variations. Hodge 11 also displays a bluer second population in the horizontal branch, which is evidence for helium enhancement. However, even though NGC 2210 shows similarities to Hodge 11 in the main sequence, there does not appear to be a second population on NGC 2210's horizontal branch. This is the first photometric evidence that ancient LMC Globular clusters exhibit multiple stellar populations.This research has used NASA’s Astrophysics Data System. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. This work was supported in part by STScI through a grant HST-GO-14164. DG gratefully acknowledges support from the Chilean Centro de Excelencia en Astrofísica y Tecnologías Afines (CATA) BASAL grant AFB-170002. DG also acknowledges financial support from the Dirección de Investigación y Desarrollo de la Universidad de La Serena through the Programa de Incentivo a la Investigación de Académicos (PIA-DIDULS). DM gratefully acknowledges support from an Australian Research Council (ARC) Future Fellowship (FT160100206). SV gratefully acknowledges the support provided by Fondecyt reg. n. 1170518.19EnglishPublisher Copyright: © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.Galaxies: star clusters: individual (Hodge 11, NGC 2210)Magellanic Clouds2019-07-0110.1093/mnras/stz1174http://www.scopus.com/inward/record.url?scp=85068009953&partnerID=8YFLogxK