5 Conclusion

The spatially resolved kinematic observations of Hen3-1333 and Hen2-113 presented in this paper have allowed us to identify their primary orientations. Our kinematic maps also indicate that these PNe have large extended faint lobes upwardly from their compact structures. For the primary lobes of Hen3-1333 and Hen2-113, we derived the inclination angles of $ i=-30^{\circ}$ and $ 40^{\circ}$, respectively. Accordingly, the main orientations of Hen3-1333 and Hen2-113 were found to be PA  $ =-15^{\circ}$ and $ 65^{\circ}$ in the ECS, in excellent agreement with the HST studies by Chesneau et al. (2006) and Lagadec et al. (2006), respectively. Interestingly, both Hen3-1333 and Hen2-113 have the same stellar characteristics (De Marco & Crowther, 1998), but they show different expansion velocities (see Table 2). Therefore, it seems that their nebular kinematic features are somehow unrelated to their stellar characteristics.

Both Hen3-1333 and Hen2-113 demonstrate a dual-dust chemistry consisting of carbon-rich and oxygen-rich grains (Cohen et al., 2002; Cohen et al., 1999; De Marco et al., 2002). Cohen et al. (2002) also found the same properties in other PNe with late-type [WC] stars. Moreover, Górny et al. (2010) found more PNe with dual-dust chemistry in the Galactic bulge, and speculated that the simultaneous presence of O-rich and C-rich dust grains is more likely related to the stellar evolution in a close binary system. Recently, Guzman-Ramirez et al. (2014) identified the presence of dense central tori in PNe with dual-dust chemistry, suggesting the possible formation through a common-envelope phase. Meanwhile, some recent kinematic studies of bipolar PNe around close-binary central stars indicate that their binary orbital inclinations are very close to their nebular inclinations (see e.g. Jones et al., 2012; Tyndall et al., 2012; Huckvale et al., 2013). Therefore, deeper observations of the central stars of Hen3-1333 and Hen2-113 will lead to a better understanding of their bipolar morphology and dual-dust chemistry. The presence of a stellar companion should be inspected. However, it is extremely difficult to detect a substellar companion, which could also affect the nebular properties.

Ashkbiz Danehkar