2025AJ....169..335L

We report the combined JWST Near Infrared Spectrograph (NIRSpec)/G395H and the Near Infrared Imager and Slitless Spectrograph (NIRISS)/Single Object Slitless Spectroscopy (SOSS) transmission spectrum of the transiting super-Jupiter HAT-P-14 b, from 0.60 to 5.14 μm. Initial analysis of these data reported a near-featureless spectrum at NIRSpec wavelengths range (2.87-5.14 μm) consistent with the small atmospheric scale height of the planet and unexplained bumps and wiggles at NIRISS wavelengths range (0.6-2.8 μm). Here, we produce a self-consistent spectrum of HAT-P-14 b's atmosphere with an up-to-date reduction. We detect H₂O (3.09σ) both across NIRISS/SOSS wavelengths range and at the bluest end of NIRSpec/G395H as well as a gray cloud deck (1.90σ). We constrain the atmospheric metallicity of HAT-P-14 b to be roughly Solar, with [Fe/H] $=-0.0{8}_{-0.98}^{+0.89}$, consistent with the planet mass-metallicity relationship. The differences compared to previous works are likely due to the improved STScI jwst pipeline, which highlights the need to reanalyze the early NIRISS/SOSS transiting exoplanet targets with the latest methods. As HAT-P-14 b is placed as the 805th best target for transmission spectroscopy according to Transmission Spectroscopy Metrics, our results showcase JWST's unparalleled photometric precision which can easily characterize a thousand exoplanets' atmospheres through transmission spectroscopy.