Kavli Affiliate: Dimitri Mawet| Summary:We present high spectral resolution $L$ band (2.91–3.85 $μ$m) observations of the warm Neptune GJ 436 b from Keck II/KPIC. KPIC’s single-mode fiber feed reduces the $L$ band sky background by a factor of 100, significantly improving sensitivity compared to a seeing-limited spectrometer and enabling a tentative ($rm SNR = 3-4$) […]
Continue.. Possible stratospheric emission in the warm Neptune GJ 436 b from high-resolution spectroscopy