Multiplicity of the massive stars in the Orion Nebula cluster and implications on their formation mechanism

Th. Preibisch, H. Zinnecker, G. Weigelt, K.-H. Hofman, D. Schertl, Y. Balega

Contribution at the 33rd ESLAB Symposium Star Formation from the Small to the Large Scale

ESA, Nordwijk, November 1999

ESA Special Publications series (SP-445), in press (2000)


We present the results of a bispectrum speckle interferometric survey for binaries among the massive stars in the Orion~Nebula~cluster. Observations of 13 bright cluster members of spectral type O or B reveal 8 visual companions in total. Using the flux ratios of the resolved systems to estimate the masses of the companions, we find that the systems generally have mass ratios below 0.5. Extrapolation with correction for the unresolved systems suggests that there are at least 1.5 companions per primary star on average. This number is clearly higher than the corresponding number for low-mass primaries, suggesting that a different mechanism is at work in the formation of high-mass multiple systems than for low-mass multiple systems.

Here you can retrieve the compressed Postscript file of this paper

For detailed information see our recent paper on this project

Back to the publication list or to my homepage .