Discovery of a Fast Expanding Shell in the Inside-out Born-Again Planetary Nebula HuBi 1 Through High-Dispersion Integral Field Spectroscopy
HuBi 1 has been proposed to be member of the rare class of born-again
planetary nebulae (PNe), i.e., its central star experienced a very late thermal
pulse and ejected highly-processed material at high speeds inside the old
hydrogen-rich PN. In this letter we present GTC MEGARA integral field
spectroscopic observations of the innermost regions of HuBi 1 at high spectral
resolution $\simeq16$ km s$^{-1}$ and multi-epoch sub-arcsec images obtained
$\simeq 12$ yr apart. The analysis of these data indicates that the inner
regions of HuBi 1 were ejected $\simeq200$ yr ago and expand at velocities
$\simeq300$ km s$^{-1}$, in excellent agreement with the born-again scenario.
The unprecedented tomographic capabilities of the GTC MEGARA high-dispersion
observations used here reveal that the ejecta in HuBi 1 has a shell-like
structure, in contrast to the disrupted disk and jet morphology of the ejecta
in other born-again PNe.
Authors
J.S. Rechy-García, M.A. Guerrero, E. Santamaría, V.M.A. Gómez-González, G. Ramos-Larios, J.A. Toalá, S. Cazzoli, L. Sabin, L.F. Miranda, X. Fang, J. Liu