SPECTROPHOTOMETRY OF THE PLANETARY-NEBULA KJPN-8

Citation
R. Vazquez et al., SPECTROPHOTOMETRY OF THE PLANETARY-NEBULA KJPN-8, Monthly Notices of the Royal Astronomical Society, 296(3), 1998, pp. 564-568
Citations number
24
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
00358711
Volume
296
Issue
3
Year of publication
1998
Pages
564 - 568
Database
ISI
SICI code
0035-8711(1998)296:3<564:SOTPK>2.0.ZU;2-Y
Abstract
Flux-calibrated low-resolution spectra covering the optical wavelength range from 3400 to 7500 Angstrom have been obtained over the central region and the surroundings of the extraordinary planetary nebula (PN) KjPn 8 (PNG 112.5-00.1). The spectrum from the core is of low excitat ion with T-e(N II)= 8000 K and n(e)(S II)= 550 cm(-3). KjPn 8 is found to be a Type IPN according to the original classification scheme of P eimbert & Torres-Peimbert, with enriched He/H and N/O ratios with resp ect to mean values for PN. Increased O/H, Ne/H and Ar/H ratios over th ose of average PN reflect the possible metal-rich environment from whi ch the progenitor star formed, and also are similar to those found in the extreme Type I PN He 2-111. The N/H ratio is found to be only mode rately high compared to the average PN and consequently, the large O a bundance pulls the N/O ratio towards the lower limit of the criterion for Type I planetary nebulae (PNe) in this case. In addition, the spec tra of some knots and faint regions ia the KjPn 8 surroundings are pre sented, which show only a few spectral lines. Low electron densities r anging from 100 to 300 cm(-3) have been derived in these outer regions .