Gemini NICI Planet-Finding
Campaign
Astronomers have evidence for hundreds
of planets around stars beyond the Sun, but
only a handful are observed in direct imaging. The planets are intrinsically faint, and
detecting them near their bright host stars
adds to the challenges. The Near-Infrared Coronagraphic Imager (NICI) at Gemini South is
capable of imaging faint extrasolar planets,
reaching greater sensitivity than previous
ground- or space-based instruments. (NICI
can detect an object one million times fainter than its bright host at a projected separation of 1 arcsecond; about one two thousandth of the Moon’s apparent diameter.)
Michael Liu (University of Hawai‘i) and a large
international team from across the Gemini
partnership and beyond used NICI for the
Gemini NICI Planet-Finding Campaign, the
largest, deepest systematic search for planets through direct imaging. The result is that
fewer stars than previously expected show
evidence for planets, which will require
some updates to theories of planet formation and survival. While some low-mass
(substellar) companion objects have been
detected, the Campaign did not image any
unknown planets.
The first comprehensive result from the Campaign considers young B and A stars, of about
two times the mass of the Sun. Ba ͕