摘要:We report results from the Wide-orbit Exoplanet search with InfraRed Direct imaging, or WEIRD, a survey designedto search for Jupiter-like companions on very wide orbits (1000–5000au) around young stars (<120Myr) that areknown members of moving groups in the solar neighborhood (<70pc). Companions that share the same age,distance, and metallicity as their host while being on large enough orbits to be studied as “isolated” objects makeprime targets for spectroscopic observations, and they are valuable benchmark objects for exoplanet atmospheremodels. The search strategy is based on deep imaging in multiple bands across the near-infrared domain. For all 177objects of our sample,¢ z ab , J, [3.6], and [4.5] images were obtained with CFHT/MegaCam, GEMINI/GMOS,CFHT/WIRCam, GEMINI/Flamingos-2, and Spitzer/IRAC. Using this set of four images per target, we searchedfor sources with red¢ z ab and [3.6]–[4.5] colors, typically reaching good completeness down to 2 M Jup companions,while going down to 1 M Jup for some targets, at separations of 1000–5000au. The search yielded four candidatecompanions with the expected colors, but they were all rejected through follow-up proper motion observations. Ourresults constrain the occurrence of 1–13 M Jup planetary-mass companions on orbits with a semimajor axis between1000 and 5000au at less than 0.03, with a 95% confidence level.
关键词:planets and satellites: gaseous planets;planets and satellites: detection