J/A+A/551/A53 Kn 26, a new quadrupolar planetary nebula (Guerrero+, 2013)
Kn 26, a new quadrupolar planetary nebula.
Guerrero M.A., Miranda L.F., Ramos-Larios G., Vazquez R.
<Astron. Astrophys. 551, A53 (2013)>
=2013A&A...551A..53G 2013A&A...551A..53G
ADC_Keywords: Planetary nebulae
Keywords: infrared: ISM - planetary nebulae: general -
planetary nebulae: individual: Kn 26 - stars: AGB and post-AGB
Abstract:
Once classified as an emission line source, the planetary nebula (PN)
nature of the source Kn 26 has only recently been recognized in
digital sky surveys. To investigate the spectral properties and
spatio-kinematical structure of Kn 26, we have obtained high
spatial-resolution optical and near-IR narrow-band images,
high-dispersion long-slit echelle spectra, and intermediate-resolution
spectroscopic observations. The new data reveal an hourglass
morphology typical of bipolar PNe. A detailed analysis of its
morphology and kinematics discloses the presence of a second pair of
bipolar lobes, making Kn 26 a new member of the subclass of
quadrupolar PNe. The time lapse between the ejection of the two pairs
of bipolar lobes is much shorter than their dynamical ages, implying a
rapid change in the preferential direction of the central engine. The
chemical composition of Kn 26 is particularly unusual among PNe,
with a low N/O ratio (as for type II PNe) and a high helium abundance
(as for type I PNe), although not atypical among symbiotic stars. Such
an anomalous chemical composition may have resulted from the
curtailment of the time in the asymptotic giant branch by the
evolution of the progenitor star through a common envelope phase.
Description:
Narrow-band Hα, [NII] λ6583, and [OIII] λ5007
images of Kn 26 were acquired on June 21, 2009 using ALFOSC
(Andalucia Faint Object Spectrograph and Camera) at the 2.56m
Nordic Optical Telescope (NOT) of the Observatorio de Roque de los
Muchachos (ORM, La Palma, Spain).
Narrow-band H2 2.1218um, Brγ 2.1658um, and K continuum at
2.270um images of Kn 26 were obtained on June 27, 2010 using LIRIS
at the Cassegrain focus of the 4.2m William Herschel Telescope
(WHT) at the ORM.
Intermediate-resolution long-slit spectra of Kn 26 were obtained on
October 5, 2011 using the ALBIREO spectrograph at the 1.5m telescope
of the Observatorio de Sierra Nevada (OSN), Granada, Spain.
Long-slit high-dispersion spectroscopy on the Hα and [NII]
λ6583 lines of Kn 26 has been acquired on June 13, 2010 using
the Manchester Echelle Spectrometer (MES) mounted on the 2.1m
(f/7.5) telescope at the Observatorio Astronomico Nacional de San
Pedro Martir (OAN-SPM, Mexico).
Objects:
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RA (2000) DE Designation(s)
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21 23 09.3 +38 58 13 Kn 26 = PN G084.7-08.0 = Lan 384
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 120 10 List of fits files
fits/* . 10 Individual fits files
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 F5.3 arcsec/pix Scale ? Scale of the image
26- 29 I4 pix Nx Number of pixels along X-axis
30 A1 --- --- [x]
31- 34 I4 pix Ny ? Number of pixels along Y-axis
36- 64 A29 --- FileName Name of FITS file in subdirectory fits
66-120 A55 --- Title Title of the file
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Acknowledgements:
Martin A. Guerrero, mar(at)iaa.es
(End) Patricia Vannier [CDS] 04-Mar-2013