We model the detectability of exoplanets around stars in the Beta Pic Moving
Group (BPMG) using the Gemini Planet Imager (GPI), a coronagraphic instrument
designed to detect companions by imaging. Members of the BPMG are considered
promising targets for exoplanet searches because of their youth (~12 MY) and
proximity (median distance ~35 pc). We wrote a modeling procedure to generate
hypothetical companions of given mass, age, eccentricity, and semi-major axis,
and place them around BPMG members that fall within the V-band range of the
GPI. We count as possible detections companions lying within the GPI's field of
view and H-band fluxes that have a host-companion flux ratio placing them
within its sensitivity. The fraction of companions that could be detected
depends on their brightness at 12 Myr, and hence formation mechanism, and on
their distribution of semi-major axes. We used brightness models for formation
by disk instability and core-accretion. We considered the two extreme cases of
the semi-major axis distribution - the log-normal distribution of the nearby F
and G type stars and a power-law distribution indicated by the exoplanets
detected by the radial velocity technique. We find that the GPI could detect
exoplanets of all the F and G spectral type stars in the BPMG sample with a
probability that depends on the brightness model and semi-major axis
distribution. At spectral type K to M1, exoplanet detectability depends on
brightness and hence distance of the host star. GPI will be able to detect the
companions of M stars later than M1 only if they are closer than 10 pc. Of the
four A stars in BPMG sample, only one has V-band brightness in the range of
GPI; the others are too bright.Comment: Accepted for publication in the Astronomical Journa