Astronomy and Astrophysics, volume 565, L4-4 (2014/5-1)
Near-infrared detection and characterization of the exoplanet HD 95086b with the Gemini Planet Imager.
GALICHER R., RAMEAU J., BONNEFOY M., BAUDINO J.-L., CURRIE T., BOCCALETTI A., CHAUVIN G., LAGRANGE A.-M. and MAROIS C.
Abstract (from CDS):
HD 95086 is an intermediate-mass debris-disk-bearing star. VLT/NaCo 3.8µm observations revealed it hosts a 5±2MJup companion (HD95086b) at ≃56AU. Follow-up observations at 1.66 and 2.18µm yielded a null detection, suggesting extremely red colors for the planet and the need for deeper direct-imaging data. In this Letter, we report H-(1.7µm) and K1-(2.05µm) band detections of HD95086 b from Gemini Planet Imager (GPI) commissioning observations taken by the GPI team. The planet position in both spectral channels is consistent with the NaCo measurements and we confirm it to be comoving. Our photometry yields colors of H-L'=3.6±1.0mag and K1-L'=2.4±0.7mag, consistent with previously reported 5-σ upper limits in H and Ks. The photometry of HD95086b best matches that of 2M1207b and HR8799cde. Comparing its spectral energy distribution with the BT-SETTL and LESIA planet atmospheric models yields Teff∼600-1500K and logg∼2.1-4.5. Hot-start evolutionary models yield M=5±2MJup. Warm-start models reproduce the combined absolute fluxes of the object for M=4-14MJup for a wide range of plausible initial conditions (Sinit=8-13kB/baryon). The color-magnitude diagram location of HD95086b and its estimated Teff and logg suggest that the planet is a peculiar L-T transition object with an enhanced amount of photospheric dust.
planets and satellites: atmospheres - planets and satellites: detection - stars: individual: HD 95086 - instrumentation: adaptive optics