Skip to main content
Log in

Membership of stars in open clusters using random forest with gaia data

The European Physical Journal Special Topics Aims and scope Submit manuscript

Cite this article


Membership of stars in open clusters is one of the most crucial parameters in studies of star clusters. Gaia opened a new window in the estimation of membership because of its unprecedented 6-D data. In the present study, we used published membership data of nine open star clusters as a training set to find new members from Gaia DR2 data using a supervised random forest model with a precision of around 90%. The number of new members found is often double the published number. Membership probability of a larger sample of stars in clusters is a major benefit in determination of cluster parameters like distance, extinction and mass functions. We also found members in the outer regions of the cluster and found sub-structures in the clusters studied. The color magnitude diagrams are more populated and enriched by the addition of new members making their study more promising.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

Data Availability Statement

This manuscript has no associated data or the data will not be deposited. [Authors’ comment: Requests for access to membership data should be made to]


  1. Right Ascension (RA) is denoted by \(\alpha \) and declination (Dec) by \(\delta \). Proper motion in RA is pmra (\(\mu _{\alpha }\)) and proper motion in declination is pmdec (\(\mu _{\delta }\)) and both are in units of milli-arcseconds per year (mas/yr). Parallax is denoted by \(\omega \) and has units of (mas).

  2. The combined membership data for all the nine clusters can be requested from PH.


  1. G. Lyngå, Astron. Astrophys. 109, 213 (1982)

    ADS  Google Scholar 

  2. K.A. Janes, R.L. Phelps, Astron. J. 108, 1773 (1994).

    Article  ADS  Google Scholar 

  3. N.V. Kharchenko, A.E. Piskunov, S. Röser, E. Schilbach, R.D. Scholz, Astron. Astrophys. 438, 1163 (2005).

    Article  ADS  Google Scholar 

  4. E.D. Friel, Annurev.aa. 33, 381 (1995).

  5. C. Bonatto, L.O. Kerber, E. Bica, B.X. Santiago, Astron. Astrophys. 446, 121 (2006).

    Article  ADS  Google Scholar 

  6. W.S. Dias, B.S. Alessi, A. Moitinho, J.R.D. Lépine, Astron. Astrophys. 389, 871 (2002).

    Article  ADS  Google Scholar 

  7. N.V. Kharchenko, A.E. Piskunov, E. Schilbach, S. Röser, R.D. Scholz, Astron. Astrophys. 558, A53 (2013).

    Article  ADS  Google Scholar 

  8. S. Vasilevskis, A. Klemola, G. Preston, Astron. J. 63, 387 (1958).

    Article  ADS  Google Scholar 

  9. W.L. Sanders, Astron. Astrophys. Suppl. 27, 89 (1977)

    ADS  Google Scholar 

  10. J.L. Zhao, Y.P. He, Astron. Astrophys. 237, 54 (1990)

    ADS  Google Scholar 

  11. L. Balaguer-Núñez, M. López del Fresno, E. Solano, D. Galadí-Enríquez, C. Jordi, F. Jimenez-Esteban, E. Masana, J. Carbajo-Hijarrubia, E. Paunzen, Mon. Not. R. Astron. Soc. 492(4), 5811 (2020).

  12. Gaia Collaboration, T. Prusti, J.H.J. de Bruijne, A.G.A. Brown, A. Vallenari, C. Babusiaux, C.A.L. Bailer-Jones, U. Bastian, M. Biermann, D.W. Evans, et al., Astron. Astrophys. 595, A1 (2016).

  13. Gaia Collaboration, A.G.A. Brown, A. Vallenari, T. Prusti, J.H.J. de Bruijne, C. Babusiaux, C.A.L. Bailer-Jones, M. Biermann, D.W. Evans, L. Eyer, et al., Astron. Astrophys. 616, A1 (2018).

  14. T. Cantat-Gaudin, C. Jordi, A. Vallenari, A. Bragaglia, L. Balaguer-Núñez, C. Soubiran, D. Bossini, A. Moitinho, A. Castro-Ginard, A. Krone-Martins, L. Casamiquela, R. Sordo, R. Carrera, Astron. Astrophys. 618, A93 (2018).

    Article  ADS  Google Scholar 

  15. A. Krone-Martins, A. Moitinho, Astron. Astrophys. 561, A57 (2014).

    Article  ADS  Google Scholar 

  16. T. Cantat-Gaudin, F. Anders, A&A 633, A99 (2020).

    Article  ADS  Google Scholar 

  17. X. Gao, Astrophys. J. 869(1), 9 (2018).

    Article  ADS  Google Scholar 

  18. X.H. Gao, Res. Astron. Astrophys. 14(2), 159–164 (2014).

    Article  ADS  Google Scholar 

  19. M.A. El Aziz, I.M. Selim, A. Essam, Exp. Astron. 42(1), 49 (2016).

    Article  ADS  Google Scholar 

  20. X. Gao, Astrophys. Space Sci. 365(2), 24 (2020).

    Article  ADS  Google Scholar 

  21. X. Gao, Astron. J. 156(3), 121 (2018).

    Article  ADS  Google Scholar 

  22. M. Agarwal, K.K. Rao, K. Vaidya, S. Bhattacharya, Mon. Not. R. Astron. Soc. 502(2), 2582 (2021).

    Article  ADS  Google Scholar 

Download references


This work has made use of data from the European Space Agency (ESA) mission Gaia (, processed by the Gaia Data Processing and Analysis Consortium (DPAC, Funding for the DPAC institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Virtual observatory tools like Aladin, Vizier and TOPCAT have been used in the analysis. Astropy, Scikit Learn, Seaborn, Numpy and Pandas packages in python have been used in the analysis and visualizations. MM is very thankful to Dr. Rohan Sekhar, Associate Professor of Computational Sciences in Minerva Schools at KGI for providing necessary support and insights on the RF model.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Priya Hasan.

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mahmudunnobe, M., Hasan, P., Raja, M. et al. Membership of stars in open clusters using random forest with gaia data. Eur. Phys. J. Spec. Top. 230, 2177–2191 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: