2005ApJ...629..865G

A search for H⁺₃line emission, reported to have been detected toward the young star HD 141569A and possibly originating in a clump of planet-forming gas orbiting the star, has yielded negative results. Observations made at the United Kingdom Infrared Telescope and the Subaru Telescope during 2001-2005 covered 11 major transitions of H⁺₃from 3.42 to 3.99 µm. No H⁺₃ emission lines were detected; one marginal detection at 3.9855 µm in 2002 June was not confirmed in later spectra. The upper limits to the line strengths were significantly lower than the previously reported detections. Supplemental slit-scanning spectroscopy using adaptive optics was performed within 0".38 of HD 141569A to search for extended emission from H⁺₃, but no emission was detected. We compare our upper limit to the luminosity in H⁺₃from HD 141569A with that possible from a gas giant protoplanet and also from a jovian mass exoplanet in close orbit about its central star.