FIRST, a fibered aperture masking instrument: on-sky results

We present on-sky results obtained with the visible light prototype of the Fibered Imager foR Single Telescope(FIRST) mounted on the 3-m Shane Telescope at Lick Observatory and using its Adaptive Optics system. Thisinstrument is dedicated to high angular resolution and high dynamic range imaging. Its principle combines bothtechniques of single-mode “ber interferometry and pupil remapping. Simulations predict a dynamic range upto 10 6 at /D , or at a few tens of milliarcseconds at 630nm using an 8-m telescope. Laboratory experimentsbased on a 9-“ber prototype working in the 600nm 900nm spectral band successfully demonstrated the powerof the concept. The same prototype has been set-up on the 3-m Shane telescope in July 2010. In this paper, wepresent the on-sky results obtained in October 2011 with an improved version of the instrument using 18 “bers.They clearly show the detection of the binary star Capella at the diraction limit of the telescope.Keywords: high dynamic range imaging, high angular resolution, aperture masking, pupil remapping, “berinterferometer, Cap ella, exoplanets