star system forms. In that case, even if GU Psc
b is in all likelihood below 13 Jupiter masses,
and thus of “planetary mass,” we can wonder
if it should be called a “planet.”
At this point, it’s hard to exclude other exotic
scenarios, such as the capture by the current
host star of a free-floating planet, formed
on its own, or ejected from another star system. The host star and its companion could
also have been ejected from the system of
a more massive star. On various fronts, this
object raises many questions.
A Key to Understanding
We expect to find more of these peculiar
planets in the future. Their unique characteristics will allow us to not only study them in
great detail but also improve our knowledge
of giant exoplanets and other exotic planetary systems.
Marie-Eve Naud is a Ph.D. student at Université
de Montréal. She can be reached at:
[email protected]
Étienne Artigau is a research scientist at Université de Montréal. He can be reached at:
[email protected]
The large distance between GU Psc b and its
host star is an important attribute and a major advantage when it comes to acquiring a
detailed characterization of the companion
object. This planetary-mass companion can
be studied like few other exoplanets, because the task requires no AO systems or sophisticated high-contrast imaging methods.
We ca