We obtained optical long-slit spectra of four planetary nebulae (PNe) with low-ionization pair of knots, namely He 1-1, IC 2149, KjPn 8 and NGC 7662. These data...

Around 50 planetary nebulae (PNs) are presently known to possess ``small-scale'' low-ionization structures (LISs) located inside or outside their main nebular...

Asymmetric Planetary Nebulae (APN) are formed by bipolar outflows through various mechanism like fast rotation (Blackman et al. 2001), magnetic field (Regos &...

Using optical images and spectra of the bipolar nebula M 2-9 we show that, in addition to the well-known bright inner nebula, the object has fast, highly...

We discuss in detail the evolutionary path of the multiple-shell planetary nebula M1-46, in the light of our new observations. The velocities of the halo and...

We present optical integral field spectroscopy analysis of the main components, with the exception of the halo, as well as of the detected small-scale...

The structure and kinematics of the bipolar nebula Mz 3 have been investigated by means of HST, CTIO and ESO images and spectra. At least four distinct outflows...

We present N-body simulations of elliptical galaxy encounters into dry mergers to study the resulting unbound intergalactic stellar population, in particular...

Spectroscopic data of two relatively [O III]-luminous planetary nebulae (PNe) have been obtained with the 10.4 m Gran Telescopio Canarias. M174 and M2496 are...