Evidence for binarity in the bipolar planetary nebulae A79, He2-428 and M1-91

M. Rodriguez; R. L. M. Corradi; A. Mampaso

doi:10.1051/0004-6361:20011123

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arXiv · astro-ph/0109437

Evidence for binarity in the bipolar planetary nebulae A79, He2-428 and M1-91

M. Rodriguez·R. L. M. Corradi·A. Mampaso

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Abstract

We present low and high resolution long-slit spectra of three bipolar planetary nebulae (PNe) with bright central cores: A79, He2-428 and M1-91. He2-428 and M1-91 have high density (from 10^3.3 to 10^6.5 cm^-3) unresolved nebular cores that indicate that strong mass loss/exchange phenomena are occurring close to their central stars. An F0 star is found at the centre of symmetry of A79; its reddening and distance are consistent with the association of the star with the nebula. The spectrum of the core of He2-428 shows indications of the presence of a hot star with red excess emission, probably arising in a late-type companion. A79 is one of the richest PNe in N and He, the abundances of M1-91 are at the lower end of the range spanned by bipolar PNe, and He2-428 shows very low abundances, similar to those measured for halo PNe. The extended nebulae of A79 and He2-428 have inclined equatorial rings expanding at a velocity of approx. 15 km/s, with kinematical ages 10^4 yr. The association of these aged, extended nebulae with a dense nebular core (He2-428) or a relatively late type star (A79) is interpreted as evidence for the binarity of their nuclei.

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M. Rodriguez, R. L. M. Corradi, A. Mampaso. 2001-09-25. Evidence for binarity in the bipolar planetary nebulae A79, He2-428 and M1-91. https://doi.org/10.1051/0004-6361%3A20011123

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