Letters to Nature

Nature 394, 448-451 (30 July 1998) | doi:10.1038/28799; Received 5 January 1998; Accepted 7 May 1998

An extraordinary cluster of massive stars near the centre of the Milky Way

E. Serabyn1, D. Shupe2 & D. F. Figer3

  1. Jet Propulsion Laboratory, California Institute of Technology, MS 171-113, 4800 Oak Grove Drive, Pasadena, California 91109, USA
  2. IPAC, California Institute of Technology 100-22, Pasadena, California 91125, USA
  3. Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA

Correspondence to: E. Serabyn1 Correspondence and requests for materials should be addressed to E.S. (e-mail: Email: serabyn@tacos.caltech.edu).

The relative numbers of newborn stars of different masses in a galaxy (the initial mass function) determines whether the galaxy's interstellar gas goes mainly into long-lived low-mass stars, as in the disks of normal spiral galaxies, or into short-lived massive stars, as has been proposed for "starburst" galaxies1,2. The centre of the Milky Way is not a fully-fledged starburst region, but its star formation rate per unit volume of space is nevertheless roughly a thousand times that of the disk3,4. It is, however, very difficult to study the initial mass function near the centre, because the dust in the gas clouds obscures the starlight, and the relatively rare young stars are mixed with much more numerous older stars11. Here we report high-resolution infrared observations of a compact cluster of stars in the central region of our Galaxy. We find approximately 100 young, massive main-sequence stars, several of which seem to be among the most massive in the Galaxy. This cluster may be a weak analogue of the large star clusters in starburst galaxies, which opens the possibility of studying the starburst phenomenon through a local example.