The evolving spectrum of the planetary nebula Hen 2-260

Abstract

Aims. We analysed the planetary nebula Hen 2-260 using optical spectroscopy and photometry. We compared our observations with the data from literature to search for evolutionary changes. We also searched for photomertic variability of the central star. Methods. The object Hen 2-260 was observed with the SAAO 1.0 m telescope (photometry) and the SALT telescope (low resolution spectroscopy). We also used archival high resolution Very Large Telescope spectra and Hubble Space Telescope imaging. The nebular line fluxes were modelled with the Cloudy photoionization code to derive the stellar and nebular parameters. Conclusions. The temperature evolution of the central star can be traced using spectroscopic observations of the surrounding planetary nebula spanning a timescale of roughly a decade. This allows us to precisely determine the stellar mass, since the pace of the temperature evolution depends critically on the core mass. The method is independent of the absolute age of the nebula. The kinematical age of the nebula is consistent with the age obtained from the evolutionary track. The final mass of the central star is close to the mass distribution peak for central stars of planetary nebulae found in other studies. The object belongs to a group of young central stars of planetary nebulae showing photometric variability.

Chemical abundances in Galactic planetary nebulae withSpitzerspectra

“…6). The suggestion that they are rather peculiar and rare objects that may originate in binary systems (see Gorny et al 2010, for more details) has not been confirmed by photometric observations (Hajduk et al 2014;Hajduk, priv. comm.…”

3D pyCloudy modelling of bipolar planetary nebulae: Evidence for fast fading of the lobes

“…The line ratios are reproduced rather well by pyCloudy using a black-body T eff = 26 000 K. Hajduk et al (2014) used a stellar atmosphere model which requires a higher temperature for the same number of ionizing photons: they find 35 000 K. Hajduk et al (2014) method (from the heating rate of the central star): their age (980 yr) approximately agrees with that estimated below from the kinematics. The 1D model of Gesicki et al (2014) predicted a parabolic shape for the velocity field, with an average expansion velocity somewhat smaller than the 3D estimation presented here.…”

“…The nebula is radiation bounded, except for a narrow cone along the symmetry axis where it is matter bounded. This object was discussed in Hajduk et al (2014), where it was analysed with spherically symmetric 1D Cloudy and Torun codes. They derived a distance to this PN of 12 kpc.…”

“…They derived a distance to this PN of 12 kpc. We adopted this value, and also took the other parameters from Hajduk et al (2014). The object was also in the sample of Gesicki et al (2014), but there it was assumed to be at the distance of the Galactic bulge and therefore a smaller radius was used.…”

“…(1) Acker et al (1992); (2 Gutenkunst et al (2008); (6) Hajduk et al (2014); (7) Stasińska et al (1998); (8) Tylenda et al (1992). Notes.…”