“Most planets that we know about to date are
only known because of indirect methods that
tell us a planet is there, a bit about its orbit
and mass, but not much else,” says Macintosh.
“With GPI we directly image planets around
stars — it’s a bit like being able to dissect the
system and really dive into the planet’s atmospheric makeup and characteristics.”
GPI carried out its first observations last November — during an extremely trouble-free
debut for an extraordinarily complex astronomical instrument the size of a small car. “This
was one of the smoothest first light runs Gemini has ever seen,” says Stephen Goodsell, who
manages the project for the observatory.
For GPI’s first observations, the team targeted
previously known planetary systems, including the well-known Beta Pictoris system; in it
GPI obtained the first-ever spectrum of the
very young planet Beta Pictoris b. The first
light team also used the instrument’s polarization mode — which can detect starlight
scattered by tiny particles — to study a faint
ring of dust orbiting the very young star HR
4796A. With previous instruments, only sections of this dust ring, (which may be the debris remaining from planet formation), could
be seen, but with GPI astronomers can follow
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