R 136a in the 30 Doradus nebula resolved by holographic speckle interferometry.

The authors have performed digital speckle interferometry observations of R 136, the luminous central object in the 30 Doradus nebula. It was possible to reconstruct a diffraction-limited true image of R 136a by using R 136b and R 136c as the deconvolution keys (holographic speckle interferometry). The reconstructed image shows for the first time that R 136a is a dense star cluster consisting of 8 stars within a diameter of 1arcsec (at λ ≡ 710 nm). The dominating objects are three stars of almost identical magnitudes with separations of 0.10arcsec and 0.48arcsec. The reconstructed image has a resolution of 0.09arcsec.