Outliers: multicolour photometry guiding the search for evolved binary systems in the globular cluster 47 Tucanae

2018/09/19 by Fabíola Campos, Fabiola Campos, I. Pelisoli +19
Physics and Astronomy · #Astronomical and nuclear sciences #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Binary number #Blue straggler #Globular cluster #Hubble space telescope #Photometry (optics) #Physics #Star cluster #Stars #Stellar, planetary, and galactic studies #White dwarf #astro-ph.GA #astro-ph.SR

paper · pdf · doi:10.1093/mnras/sty2591

13 pages, 8 figures, 2 tables. Accepted for publication in MNRAS on September 18, 2018

openalex publication_date 2018/09/19 · arxiv created 2018/09/21 · arxiv updated 2018/09/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We use Hubble Space Telescope multicolour photometry of the globular cluster 47 Tucanae to uncover a population of 24 objects with no previous classification that are outliers from the single-star model tracks in the colour-magnitude diagram and yet are likely cluster members. By comparing those sources with evolutionary models and X-ray source catalogues, we were able to show that the majority of those sources are likely binary systems that do not have any X-ray source detected nearby, most possibly formed by a white dwarf and a main-sequence star and a small number of possible double-degenerate systems.

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