{"title":"A Rare Cepheid-hosting Open Cluster Triad in Sagittarius","authors":"Daniel Majaess, David G. Turner, Igor Usenko","doi":"10.3847/2515-5172/ad7139","DOIUrl":null,"url":null,"abstract":"The following Galactic star clusters may constitute a rare Cepheid hosting triad in Sagittarius: M25, NGC 6716, and Collinder 394. The open clusters have comparable ages (<italic toggle=\"yes\">τ</italic> ≃ 80 Myr) and nearly aligned main-sequences and turnoffs after accounting for differential extinction (<italic toggle=\"yes\">A</italic>\n<sub>\n<italic toggle=\"yes\">G</italic>\n</sub>, <inline-formula>\n<tex-math>\n<?CDATA ${E}_{{B}_{P}-{R}_{P}}$?>\n</tex-math>\n<mml:math overflow=\"scroll\"><mml:msub><mml:mrow><mml:mi>E</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>B</mml:mi></mml:mrow><mml:mrow><mml:mi>P</mml:mi></mml:mrow></mml:msub><mml:mo>−</mml:mo><mml:msub><mml:mrow><mml:mi>R</mml:mi></mml:mrow><mml:mrow><mml:mi>P</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:math>\n<inline-graphic xlink:href=\"rnaasad7139ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\n</inline-formula>). Gaia DR3 astrometry confirms an association between the three clusters, and importantly, the classical Cepheid U Sgr is a member (<italic toggle=\"yes\">P</italic> ≃ 6.ͩ75, <italic toggle=\"yes\">τ</italic> ≃ 80 Myr), while DR3 data indicate that the classical Cepheid BB Sgr (<italic toggle=\"yes\">P</italic> ≃ 6.ͩ64, <italic toggle=\"yes\">τ</italic> ≃ 80 Myr) could possibly be an escaped member traversing the background field.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"37 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Research notes of the AAS","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3847/2515-5172/ad7139","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The following Galactic star clusters may constitute a rare Cepheid hosting triad in Sagittarius: M25, NGC 6716, and Collinder 394. The open clusters have comparable ages (τ ≃ 80 Myr) and nearly aligned main-sequences and turnoffs after accounting for differential extinction (AG, EBP−RP). Gaia DR3 astrometry confirms an association between the three clusters, and importantly, the classical Cepheid U Sgr is a member (P ≃ 6.ͩ75, τ ≃ 80 Myr), while DR3 data indicate that the classical Cepheid BB Sgr (P ≃ 6.ͩ64, τ ≃ 80 Myr) could possibly be an escaped member traversing the background field.