%0 Journal Article
%A Contreras, C. S.
%A Gil De Paz, Armando
%A Sahai, R.
%T The companion to the central mira star of the protoplanetary nebula OH 231.8+4.2
%D 2004
%@ 0004-637X
%U https://hdl.handle.net/20.500.14352/51797
%X We present deep optical long-slit spectra of the peculiar protoplanetary nebula (PPN) OH 231.8+4.2 obtained with the 6.5 m Baade Telescope at Las Campanas Observatory (Chile). In addition to the molecular absorption bands characteristic of the M9–10 III star inside OH 231.8+4.2 (QX Pup), we identify lines of the Balmer series in absorption, which do not form in the cool atmospheres of late M-type stars. We also confirm the presence of a blue continuum excess with an intensity that is a factor  ~30 larger than that expected for an M9–10 III star. Our results indicate the presence of a source hotter than QX Pup illuminating OH 231.8+4.2 that is likely a mainsequence star with spectral type A. We discuss how the formation and nebular evolution of OH 231.8+4.2 could have been affected by the presence of a binary system in its core.
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