oai:arXiv.org:2406.00107
sciences: astrophysics
2024
6/19/2024
Recently, Biddle et al. (2024) claimed a non-detection of the protoplanet AB Aurigae b in Keck/NIRC2 Pa$\beta$ imaging.
I reprocess these newly-public data and compare them to data from the extreme AO platform (SCExAO/CHARIS) used to discover AB Aur b. AB Aur b is decisively imaged with SCExAO/CHARIS at wavelengths covering Pa$\beta$.
The Biddle et al. non detection of AB Aur b results from a far poorer image quality that is non competitive with SCExAO/CHARIS.
Their contrast limits and thus constraints on accretion are overestimated due to an inaccurate AB Aur b source model.
Consequentially, the revised Pa$\beta$ 2-$\sigma$ upper limit from these data is about three times higher than previously reported.
Irrespective of image quality, single-band Pa$\beta$ imaging is ill suited to conclusively identifying accretion onto AB Aur b. Instead, high-resolution H$\alpha$ spectroscopy may provide accretion signatures.
Aside from PDS 70, AB Aurigae remains the system with the strongest evidence for having a directly-imaged protoplanet.
;Comment: 5 pages, 2 figures; author's preprint version of published article in RNAAS (expanded title and additional clarifying text)
Currie, Thayne, 2024, Direct Imaging Detection of the Protoplanet AB Aurigae b at Wavelengths Covering Pa$\beta$: Rebuttal to Biddle et al. (2024)