Unveiling the binary nature of NGC 2323
Context . As a well-known open cluster, NGC 2323 (also called M50) has been widely investigated for over a hundred years and has always been considered a classical single cluster. Aims . We studied the binary structure nature of NGC 2323 with Gaia Data Release 3 (DR3). Methods . We discovered the binary structure of NGC 2323 by the HDBSCAN algorithm based on the astrometric and photometric data from Gaia DR3. Then we employed the PETAR N -body code to investigate its binary structure origin. Results . We found that NGC 2323 consists of two distinct subclusters (NGC 2323-a and NGC 2323-b) that are still gravitationally bound. They have very close positions (three-dimensional Δpos = 12.3 pc, σ Δpos = 3.4 pc) and similar tangential velocities (two-dimensional ΔV = 2.2 km s −1 , σ ΔV = 0.02 km s −1 ). The best isochrone fitting ages of the two clusters are the same (158 Myr), further proving their possibly common origin. The numerical N -body simulation suggests that the less massive cluster is unlikely to be the cluster tidal tails created by the differential rotation of the Milky Way.
Authors
- Kai Wu (ORCID: https://orcid.org/0000-0002-5016-0251)
- Songmei Qin (ORCID: https://orcid.org/0000-0003-3713-2640)
- Jing Zhong (ORCID: https://orcid.org/0000-0001-5245-0335)
- L. Balaguer-Núñez (ORCID: https://orcid.org/0000-0001-9789-7069)
- F. Anders (ORCID: https://orcid.org/0000-0003-4524-9363)
- Guimei Liu
- Yueyue Jiang (ORCID: https://orcid.org/0000-0002-4986-2408)
- Li Chen (ORCID: https://orcid.org/0000-0002-4907-9720)
- Chunyan Li (ORCID: https://orcid.org/0000-0003-2021-4818)
- Long Wang (ORCID: https://orcid.org/0000-0002-9882-108X)
- Jinliang Hou (ORCID: https://orcid.org/0000-0002-6193-5307)
- Tong Tang (ORCID: https://orcid.org/0000-0003-1864-8721)
Institutions
- Sun Yat-sen University (CN)
- China West Normal University (CN)
- Chinese Academy of Sciences (CN)
- Heidelberg University (DE)
- Shanghai Astronomical Observatory (CN)
- Xinjiang Astronomical Observatory (CN)
- Institut d'Estudis Espacials de Catalunya (ES)
- Institut Català de Ciències del Clima (ES)
- University of Chinese Academy of Sciences (CN)
- Universitat de Barcelona (ES)
- Universitat Politècnica de Catalunya (ES)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1051/0004-6361/202452962
- Citations
- 6
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 6.93
Funders
- European Space Agency
- European Commission
- Deutsche Forschungsgemeinschaft
- National Natural Science Foundation of China
- Sun Yat-sen University
- Science and Technology Commission of Shanghai Municipality
- China Scholarship Council
- Youth Innovation Promotion Association of the Chinese Academy of Sciences
- Universitat de Barcelona
- European Regional Development Fund
- Agencia Estatal de Investigación
- Fundamental Research Funds for the Central Universities
- Program of Shanghai Academic Research Leader
- Youth Innovation Promotion Association
- Institut de Ciències del Cosmos