The Blue Straggler Population of the Open Clusters Trumpler 5, Trumpler 20, and NGC 2477
- Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo Osservatorio 3, I-35122, Padova (Italy)
- Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, X5000BGR, Córdoba (Argentina)
- Departamento de Astronomía, Universidad de Concepción, 160 Casilla, Concepción (Chile)
- ESO, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany)
- Departamento de Ciencias Fisicas, Universidad Andres Bello, Santiago de Chile (Chile)
We present a study based on Gaia DR2 of the population of blue straggler stars in the open clusters Trumpler 5, Trumpler 20, and NGC 2477. All candidates were selected according to their position in the color–magnitude diagram, their proper motion components, and their parallax. We also looked for yellow stragglers, i.e., possible evolved blue stragglers. We found that Trumpler 5 hosts a large blue straggler star population, which allowed us to analyze their radial distribution as a probe of the cluster’s dynamical status. The blue straggler star distribution was compared with that of red giant branch stars to evaluate mass segregation. Our results indicate that blue straggler stars are not more centrally concentrated than red giant branch stars stars in any of the clusters. The radial distribution of blue straggler stars in Trumpler 5 is flat. Additionally, using a multi-epoch radial velocity survey conducted with the high-resolution spectrograph FLAMES/GIRAFFE at the Very Large Telescope, we measured the radial velocities of a sample of stragglers to compare with the mean radial velocity and velocity dispersion of the clusters. Based on the radial velocity variations for different epochs, we roughly classified these stars as possible close or long-period binaries.
- OSTI ID:
- 23159073
- Journal Information:
- The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 1 Vol. 161; ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
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