VLT/MUSE Hα and Hβ observations of the AB Aur planetary system

We conducted Hα and Hβ observations of the protoplanet AB Aur b using VLT/MUSE. However, we were unable to detect Hα and Hβ emissions from AB Aur b in our observations. The 5σ detection limit for Hα was achieved at 7.3e-15 erg/s/cm², which was lower than the previously reported Hα flux of 1.3–1.4e-14 erg/s/cm². Our findings do not necessarily rule out the presence of accretion in AB Aur b since our PSF subtraction process may result in non-detection when the line profiles of the star and the planet are similar. Assuming that AB Aur b’s Hα flux is the same as the previously reported value, we estimated a lower limit for the extinction, A_H ≳ 0.9 mag, attributing the non-detection of Hβ to extinction. Considering the effects of extinction, the observation of near-infrared emission lines such as Paβ will be valuable for understanding the accretion properties of AB Aur b and confirming its status as a planetary object.