Open AccessSpectrophotometry of the planetary nebula KjPn 8
Author(s) -
Vázquez R.,
Kingsburgh R. L.,
López J. A.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01410.x
Subject(s) - physics , planetary nebula , astrophysics , spectral line , nebula , spectral resolution , electron excitation , doubly ionized oxygen , wavelength , stars , emission spectrum , astronomy , excitation , optics , quantum mechanics
Flux‐calibrated low‐resolution spectra covering the optical wavelength range from 3400 to 7500 Å 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 excitation with T e (N II ) = 8000 K and n e (S II ) = 550 cm −3 . KjPn 8 is found to be a Type I PN according to the original classification scheme of Peimbert & Torres‐Peimbert, with enriched He/H and N/O ratios with respect to mean values for PN. Increased O/H, Ne/H and Ar/H ratios over those of average PN reflect the possible metal‐rich environment from which 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 moderately high compared to the average PN and consequently, the large O abundance pulls the N/O ratio towards the lower limit of the criterion for Type I planetary nebulae (PNe) in this case. In addition, the spectra of some knots and faint regions in the KjPn 8 surroundings are presented, which show only a few spectral lines. Low electron densities ranging from 100 to 300 cm −3 have been derived in these outer regions.