We report a non-detection of nightside emission from the warm super-Neptune HAT-P-26 b. Following a similar approach to that presented by J. Lustig-Yaeger et al. for WASP-17 b, we attempted to extract the nightside emission spectrum using the in-eclipse spectrum removal method to detect planetary infrared excess (PIE). However, our methods did not yield a reliable nightside spectrum for HAT-P-26 b, and instead the results appear consistent with contamination due to small changes in the star between transit and eclipse visits. This null result helps to illuminate astrophysical challenges that complicate applications of the PIE technique and highlight the need for close-in-time transit and eclipse observations for this analysis method.
Sotzen et al. (Mon,) studied this question.