L '-band AGPM vector vortex coronagraph's first light on VLT/NACO Discovery of a late-type companion at two beamwidths from an F0V star

Context. High contrast imaging has thoroughly combed through the limited search space accessible with first-generation ground-based adaptive optics instruments and the Hubble Space Telescope. Only a few objects were discovered, and many non-detections reported and statistically interpreted. The field is now in need of a technological breakthrough. Aims. Our aim is to open a new search space with first-generation systems such as NACO at the Very Large Telescope, by providing ground-breaking inner working angle (IWA) capabilities in the L' band. The L' band is a sweet spot for high contrast coronagraphy since the planet-to-star brightness ratio is favorable, while the Strehl ratio is naturally higher. Methods. An annular groove phase mask (AGPM) vector vortex coronagraph optimized for the L' band made from diamond subwavelength gratings was manufactured and qualified in the lab. The AGPM enables high contrast imaging at very small IWA, potentially being the key to unexplored discovery space. Results. Here we present the installation and successful on-sky tests of an L'-band AGPM coronagraph on NACO. Using angular differential imaging, which is well suited to the rotational symmetry of the AGPM, we demonstrated a Delta L' > 7.5 mag contrast from an IWA similar or equal to 0 ''.09 onwards, during average seeing conditions, and for total integration times of a few hundred seconds.

Absil, OlivierUniversité de Liège, Belgium (author)
Delacroix, ChristianUniversité de Liège, Belgium (author)
Girard, J. H.European Southern Observatory, Chile (author)
Milli, J.European Southern Observatory, Chile (author)
O'Neal, J.European Southern Observatory, Chile (author)
Baudoz, PierreLESIA, Observatoire de Paris, France (author)
Boccaletti, A.LESIA, Observatoire de Paris, France (author)
Bourget, P.European Southern Observatory, Chile (author)
Christiaens, V.Université de Liège, Belgium (author)
Forsberg, PontusUppsala universitet,Tillämpad materialvetenskap(Swepub:uu)ponfo524 (author)
Gonte, F.European Southern Observatory, Chile (author)
Habraken, SergeUniversité de Liège, Belgium (author)
Hanot, C.Université de Liège, Belgium (author)
Karlsson, MikaelUppsala universitet,Tillämpad materialvetenskap(Swepub:uu)mka11187 (author)
Kasper, M.European Southern Observatory Headquarters, Germany (author)
Lizon, J. -LEuropean Southern Observatory Headquarters, Germany (author)
Muzic, K.European Southern Observatory, Chile (author)
Olivier, R.GDTech s.a., Belgium (author)
Pena, E.European Southern Observatory, Chile (author)
Slusarenko, N.European Southern Observatory, Chile (author)
Tacconi-Garman, L. E.European Southern Observatory Headquarters, Germany (author)
Surdej, J.Université de Liège, Belgium (author)
European Southern Observatory, ChileUniversité de Liège, Belgium (creator_code:org_t)

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.