High Contrast Imaging with the New Vortex Coronagraph on NACO

Mawet, D.; Absil, O.; Girard, J. H.; Milli, J.; O'Neal, J.; Delacroix, C.; Baudoz, P.; Boccaletti, A.; Bourget, P.; Christiaens, V.; Forsberg, P.; Gonté, F.; Habraken, S.; Hanot, C.; Karlsson, M.; Kasper, M.; Lagrange, A.; Lizon, J.; Muzic, K.; Peña, E.; Olivier, R.; Slusarenko, N.; Tacconi-Garman, L. E.; Surdej, J.
The Messenger, vol. 152, p. 8-13 (2013).


The installation and successful commissioning of an L'-band annular groove phase mask (AGPM) coronagraph on VLT/NACO is presented. The AGPM is a vector vortex coronagraph made from diamond sub-wavelength gratings tuned to the L'-band. The vector vortex coronagraph enables high-contrast imaging at very small inner working angles (here 0.09 arcseconds, the diffraction limit of the VLT at L'), potentially opening up a new parameter space in high-resolution imaging. During technical and science verification runs, we discovered a late-type companion at two beamwidths from an F0V star, and imaged the inner regions of β Pictoris down to the previously unexplored projected radius of 1.75 astronomical units. The circumstellar disc of β Pic was also resolved from 1 to 5 arcseconds. These results showcase the potential of the NACO L'-band AGPM over a wide range of spatial scales.