Cygnus OB2 – a young globular cluster in the Milky Way Jürgen Knödlseder To cite this version: Jürgen Knödlseder. Cygnus OB2 – a young globular cluster in the Milky Way. Astronomy and Astrophysics - A&A, EDP Sciences, 2000, 360, pp.539 - 548. hal-01381935 HAL Id: hal-01381935 https://hal.archives-ouvertes.fr/hal-01381935 Submitted on 14 Oct 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Astron. Astrophys. 360, 539–548 (2000) ASTRONOMY AND ASTROPHYSICS Cygnus OB2–ayoung globular cluster in the Milky Way J. Knodlseder¨ INTEGRAL Science Data Centre, Chemin d’Ecogia 16, 1290 Versoix, Switzerland Centre d’Etude Spatiale des Rayonnements, CNRS/UPS, B.P. 4346, 31028 Toulouse Cedex 4, France (
[email protected]) Received 31 May 2000 / Accepted 23 June 2000 Abstract. The morphology and stellar content of the Cygnus particularly good region to address such questions, since it is OB2 association has been determined using 2MASS infrared extremely rich (e.g. Reddish et al. 1966, hereafter RLP), and observations in the J, H, and K bands. The analysis reveals contains some of the most luminous stars known in our Galaxy a spherically symmetric association of ∼ 2◦ in diameter with (e.g.