Precessing collimated outflows in the planetary nebula IC 4846

Citation
Lf. Miranda et al., Precessing collimated outflows in the planetary nebula IC 4846, M NOT R AST, 322(1), 2001, pp. 195-200
Citations number
15
Categorie Soggetti
Space Sciences
Journal title
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
ISSN journal
00358711 → ACNP
Volume
322
Issue
1
Year of publication
2001
Pages
195 - 200
Database
ISI
SICI code
0035-8711(200103)322:1<195:PCOITP>2.0.ZU;2-I
Abstract
We present [N ii] and H alpha images and high-resolution long-slit spectra of the planetary nebula IC 4846, which reveal, for the first time, its comp lex structure and the existence of collimated outflows. The object consists of a moderately elongated shell, two (and probably three) pairs of collima ted bipolar outflows at different orientations, and an attached circular sh ell. One of the collimated pairs is constituted by two curved, extended fil aments the properties of which indicate a high-velocity, bipolar precessing jet. A difference of similar or equal to 10 km s(-1) is found between the systemic velocity of the precessing jets and the centroid velocity of the n ebula, as recently reported for Hu 2-1. We propose that this difference is as a result of orbital motion of the ejection source in a binary central st ar. The orbital separation of less than or equal to 30 au and period less t han or equal to 100 yr estimated for the binary are similar to those in Hu 2-1, linking the central stars of both planetary nebulae to interacting bin aries. Extraordinary similarities also exist between IC 4846 and the bewild ering planetary nebula NGC 6543, suggesting a similar formation history for both objects.