The Subaru Seminar is
usually held in Room 104 of the Hilo Base Facility, adjacent
to the main lobby. Everyone is welcome to attend. If you are
interested in giving a seminar, please contact Subaru seminar organizers
(Tomonori Usuda, Kumiko S. Usuda, Naoyuki Tamura)
by email : sseminar_at_subaru.naoj.org (please change"_at" to @).
November 25, Tuesday at 2:00 pm
" Aperture Masking Interferometry with AO: does Subaru collect too many photons? "
Frantz Martinache (Subaru Telescope, NAOJ)
While the existence of large numbers of extrasolar planets around solar type stars has been unambiguously demonstrated by radial velocity, transit and microlensing surveys, attempts at their direct imaging with AO-equipped large telescopes remain largely unsuccessful.
Indeed, current surveys are limited by modest AO performance which do not probe the central 0.2" around the star, and only reach maximum sensitivity outside 1".
Even on most nearby systems, this translates into orbital distances greater than 10 AU, where massive planets are probably rare (as suggested by the results of these surveys).
A handful of candidates have yet been imaged (e.g. 2M1207 or GQ Lupi), but their planetary status remains model-dependent and controversial (Neuhauser et al, 2005; Biller et al, 2006).
Moreover, neither core accretion (Mizuno, 1980) nor disk instability (Cameron 1978, Boss 1997) planet formation models alone can account for the existence of these planets, at orbital distances greater than 50 AU.
To be able to directly detect extrasolar planets within 10 AU, or to explore the "Goldlilock zone" of nearby stars, one needs just one thing: mask about 90 % of the primary mirror of the telescope!
I just spent the last three years at Cornell University working to the development of a successful high-angular resolution technique called non-redundant aperture masking interferometry with AO, which manages to look for companions at separations as low as 0.02" on an 8-meter telescope.
I'll explain you how it works, show you the kind of science I've been able to do with this fun technique with the Palomar 200" and the Keck II telescopes and will discuss its possible implementation onto Subaru.
Seminars are also held at JAC,