We will present the first on-sky demonstration of the Fibered Imager foR a Single Telescope (FIRST) instrument at the Subaru Telescope. Using techniques of aperture masking and spatial filtering, FIRST combines the power of spectro-interferometry to deliver high contrast capabilities and spatial resolutions beyond the reach of traditional coronagraphic instruments.

We will explain the 'pupil remapping' technique - the heart of the FIRST instrument - and its practical applications. This process divides the telescope pupil into sub-pupils, enabling simultaneous measurements of all baseline fringe patterns. Our researchers tested this instrument on two types of targets: a point source (Keho'oea - α Lyrae) and a binary system (Hokulei - α Aurigae), achieving a contrast and stability sufficient to study the close surroundings of those stars.

The successful demonstration of FIRST signifies a significant step forward for future interferometric instrumentation on extremely large telescopes, opening new observing capabilities in the visible wavelength range at the Subaru Telescope.

With the SETI Institute's Franck Marchis and Sebastien Vievard, exoplanet instrumentation scientist on SCExAO.

Recorded live 20 July 2023