@article{a9ce12859ffe45f0964cc0169e5fdc61,
title = "Extended halo of NGC 2682 (M 67) from Gaia DR2",
abstract = "Context. NGC 2682 is a nearby open cluster that is approximately 3.5 Gyr old. Dynamically, most open clusters are expected to dissolve on shorter timescales of ≈1 Gyr. That it has survived until now means that NGC 2682 was likely much more massive in the past and is bound to have an interesting dynamical history. Aims. We investigate the spatial distribution of the stars in NGC 2682 to constrain dynamical evolution of the cluster. We particularly focus on the marginally bound stars in the cluster outskirts. Methods. We used Gaia DR2 data to identify NGC 2682 members up to a distance of ∼150 pc (10°). The two methods Clusterix and UPMASK were applied to this end. We estimated distances to obtain 3D stellar positions using a Bayesian approach to parallax inversion, with an appropriate prior for star clusters. We calculated the orbit of NGC 2682 using the GRAVPOT16 software. Results. The cluster extends up to 200′ (50 pc), which implies that its size is at least twice as large as previously believed. This exceeds the cluster Hill sphere based on the Galactic potential at the distance of NGC 2682. Conclusion. The extra-tidal stars in NGC 2682 may originate from external perturbations such as disc-shocking or dynamical evaporation from two-body relaxation. The former origin is plausible given the orbit of NGC 2682, which crossed the Galactic disc ≈40 Myr ago.",
keywords = "Astrometry, Open clusters and associations: individual: NGC 2682",
author = "R. Carrera and M. Pasquato and A. Vallenari and L. Balaguer-N{\'u}{\~n}ez and T. Cantat-Gaudin and M. Mapelli and A. Bragaglia and D. Bossini and C. Jordi and D. Galad{\'i}-Enr{\'i}quez and E. Solano",
note = "Funding Information: Acknowledgements. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https: //www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This project has received funding from the European Union{\textquoteright}s Horizon 2020 research and innovation programme under the Marie Sk{\l}odowska-Curie grant agreement No. 664931 This work was partly supported by the MINECO (Spanish Ministry of Economy) through grant ESP2016-80079-C2-1-R (MINECO/FEDER, UE) and MDM-2014-0369 of ICCUB (Unidad de Excelencia “Mar{\'i}a de Maeztu”), European Community{\textquoteright}s Seventh Framework Programme (FP7/2007-2013) under grant agreement GENIUS FP7 – 606740 and the European Commission Framework Programme Horizon 2020 Research and Innovation action under grant agreement ASTERICS 653477. Support from PREMIALE 2016 MITiC is acknowledged. Based on Clusterix 2.0 service at CAB (INTA-CSIC). DB is supported in the form of work contract FCT/MCTES through national funds and by FEDER through COMPETE2020 in connection to these grants: UID/FIS/04434/2019; PTDC/FIS-AST/30389/2017 and POCI-01-0145-FEDER-030389 Publisher Copyright: {\textcopyright} ESO 2019.",
year = "2019",
month = jul,
day = "1",
doi = "10.1051/0004-6361/201935599",
language = "English (US)",
volume = "627",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}