Rachel Matson and Andy Stephens
Speckle Imaging Takes Gemini to
Its Diffraction Limit
For nearly a decade, speckle imaging at Gemini Observatory has
produced an abundance of notable results, including a monumental
breakthrough in exoplanet research in binary star systems. Now with
the recent addition of an innovative pair of powerful high-resolution
speckle instruments to permanently reside at Gemini North and
South, the Observatory stands on the forefront of high-resolution
ground-based exploration.
Recently our team at the NASA Ames Research Center authored a high-impact journal ar-
ticle that featured key Gemini data on the transit by a giant exoplanet of one of the com-
ponents of the Kepler-13AB binary star system. system. This study, led by Steve Howell, not
only classified the Jupiter-sized exoplanet (Kepler-13b) in this close binary system but, in a
first for ground-based imaging, conclusively determined which star the planet orbits. The
Gemini press release on our finding is reprinted starting on page 10 of this issue, and The
Astronomical Journal paper is available here.
To execute this type of diffraction-limited science and uncover the hidden secrets of close
exoplanet binary star systems, in which about one half of all exoplanets reside, our team
designed under Howell’s leadership an innovative pair of twin instruments that perform
high-resolution “speckle imaging” — collecting a thousand 60-millisecond exposures ev-
ery minute; after processing this large amount of data, the final images are free of the
adverse effects of atmospheric turbulence which can bloat, blur, and distort star images.
Our team aptly named the two permanently mounted instruments Zorro and ‘Alopeke,
which come from the Spanish and Hawaiian (respectively) words for fox — because the in-
struments are both speedy and sly like foxes. The instruments were built to take advantage
October 2019
GeminiFocus
7