Early-type stars in the young open cluster NGC 2244 and in the Monoceros OB2 association. I. The mul

  title={Early-type stars in the young open cluster NGC 2244 and in the Monoceros OB2 association. I. The mul},
  author={L. Mahy and Y. Naz{\'e} and G. Rauw and E. Gosset and M. D. Becker and H. Sana and P. Eenens},
  journal={Astronomy and Astrophysics},
Aims. We present the results obtained from a long-term spectroscopic campaign devoted to the multiplicity of O-type stars in the young open cluster NGC 2244 and in the Mon OB2 association. Methods. Our spectroscopic monitoring was performed over several years, allowing us to probe different time-scales. For each star, several spectral diagnostic tools are applied, in order to s earch for line shifts and profile variations. We also measure the projected rotational velocity and revisit the… Expand
A spectroscopic investigation of early-type stars in the young open cluster Westerlund 2
Context. The distance of the very young open cluster Westerlund 2, which contains the very massive binary system WR 20a and is likely associated with a TeV source, has been the subject of muchExpand
A spectroscopic investigation of the O-type star population in four Cygnus OB associations I. Determination of the binary fraction
Context. Establishing the multiplicity of O-type stars is the first st ep towards accurately determining their stellar parameters. Moreover, the distribution of the orbital parameters provi desExpand
A quantitative study of O stars in NGC 2244 and the Monoceros OB2 association
Aims. Our goal is to determine the stellar and wind properties of seven O stars in the cluster NGC 2244 and three O stars in the OB association Mon OB2. These properties give us insight into the massExpand
With an orbital period of about 3.078 days, the double-lined spectroscopic binary HD 48099 is, until now, the only short-period O+O system known in the Mon OB2 association. Even though an orbitalExpand
Massive binaries in the vicinity of Sgr A
A long-term spectroscopic and photometric survey of the most luminous and massive stars in the vicinity of the supermassive black hole Sgr A* revealed two new binaries: a long-period Ofpe/WN9 binary,Expand
A quantitative study of the O stars in NGC 2244
NGC 2244 located in the Rosette Nebula is a young open cluster composed of seven O-type stars. A first paper focused on the multiplicity of these stars, revealed only one binary system out of theExpand
Variability in the CoRoT photometry of three hot O-type stars HD 46223, HD 46150, and HD 46966
Context. The detection of pulsational frequencies in stellar photometry is required as input for asteroseismological modelling. The second short run (SRa02) of the CoRoT mission has providedExpand
The young massive SMC cluster NGC 330 seen by MUSE
A majority of massive stars are part of binary systems, a large fraction of which will inevitably interact during their lives. Binary-interaction products (BiPs), i.e. stars affected by suchExpand
Further results from the galactic O-Star Spectroscopic Survey: rapidly rotating late ON giants
With new data from the Galactic O-Star Spectroscopic Survey, we confirm and expand the ONn category of late-O, nitrogen-enriched (N), rapidly rotating (n) giants. In particular, we have discoveredExpand
The multiplicity of massive stars
  • H. Sana, C. Evans
  • Physics
  • Proceedings of the International Astronomical Union
  • 2010
Abstract Binaries are excellent astrophysical laboratories that provide us with direct measurements of fundamental stellar parameters. Compared to single isolated stars, multiplicity induces newExpand


The massive star binary fraction in young open clusters – I. NGC 6231 revisited
We present the results of a long-term high-resolution spectroscopy campaign on the O-type stars in NGC 6231. We revise the spectral classification and multiplicity of these objects and we constrainExpand
High-mass binaries in the very young open cluster NGC 6231. Implication for cluster and star formation
New radial-velocity observations of 37 O- and B stars in the very young open cluster NGC 6231 confirm the high frequency of short-period spectroscopic binaries on the upper main sequence. Among theExpand
Early-type stars in the young open cluster IC 1805. II. The probably single stars HD 15570 and HD 15629, and the massive binary/triple system HD 15558
Aims. We address the issue of the multiplicity of the three brightest early-type stars of the young open cluster IC 1805, namely HD 15570, HD 15629 and HD 15558. Methods. For the three stars, weExpand
Radial-velocity measurements in 20 young open clusters
The further results of a program to determine the radial velocities of young open clusters are presented. Using the KPNO coude spectrograph coupled with the 1-m feed and 2.1-m telescopes, radialExpand
A Chandra Study of the Rosette Star-forming Complex. I. The Stellar Population and Structure of the Young Open Cluster NGC 2244
We present the first high spatial resolution X-ray study of NGC 2244, the 2 Myr old stellar cluster in the Rosette Nebula, using Chandra. Over 900 X-ray sources are detected; 77% have optical orExpand
The Initial Mass Function and Massive Star Evolution in the OB Associations of the Northern Milky Way
We investigate the massive star content of Milky Way clusters and OB associations in order to answer three questions: (1) How coeval is star formation? (2) How constant is the initial mass functionExpand
The OB binary HD 152219: a detached, double-lined, eclipsing system*
We present the results of an optical spectroscopic campaign on the massive binary HD 152219 located near the core of the NGC6231 cluster. Though the primary to secondary optical brightness ratio isExpand
The origin of massive O-type field stars. I. A search for clusters
We present a study aimed at clarifying the birthplace for 43 massive O-type field stars. In this first paper we present the observational part: a search for stellar clusters near the target stars. WeExpand
An XMM–Newton view of the young open cluster NGC 6231 – II. The OB star population★
In this second paper of the series, we pursue the analysis of the 180-ks XMM‐Newton campaign towards the young open cluster NGC 6231 and we focus on its rich OB star population. We present aExpand
Mass Segregation in Very Young Open Clusters: A Case Study of NGC 2244 and NGC 6530
We derive the proper motions, membership probabilities, and velocity dispersions of stars in the regions of the young (similar to 2 - 4 Myr old) open clusters NGC 2244 ( the central cluster in theExpand