Bibcode
Manchado, A.; Guerrero, M. A.; Stanghellini, L.; Serra-Ricart, M.
Bibliographical reference
American Astronomical Society, 189th AAS Meeting, late abstracts, #120.14; Bulletin of the American Astronomical, Vol. 29, p. 732
Advertised on:
1
1997
Citations
3
Refereed citations
2
Description
Planetary Nebulae (PNe) are highly representative of the last stages of
intermediate mass stellar evolution. However, there are still many
unresolved questions concerning their evolutionary scheme. Mass loss
processes during the Asymptotic Giant Branch (AGB) are not fully
understood. Binarity, rotation and magnetic fields may play an important
role in PNe formation. The morphological study of PNe will help to
address those questions, and therefore a rational and homogeneous data
base is needed. Searching through the literature we have not found a
homogeneous catalog of northern PNe. There are only some incomplete
works of a few dozen PNe (Balick 1987; Chu et al 1987), and an
incomplete catalog of southern PNe (Schwarz et al. 1992). We aim to fill
the gap by compiling a complete catalog of extended northern PN. This
catalog has the following characteristics: (a) It is homogeneous (all
the images were obtained with the same instrument), and complete for all
the PNe with -10(deg) < delta and with diameters larger than {4('')
}, as stellar PNe cannot be used for this kind of study. (b) In order to
obtain a sharp image of the different ionized regions, images were
obtained through narrow band filters: Hα , [N {ii}] and [O iii].
(c) It excludes all the objects with doubtful classifications, as well
as the PNe included in Balick (1987) and Schwarz et al. (1992). Since
the summer 1993, 243 objects were observed. 143 PN have diameters bigger
than {12('') } and were observed with the 80 cm IAC80 telescope at the
Observatorio del Teide (Tenerife). The other 100 PN have diameters
between {4('') } and {12('') } and were observed with the 2.54 m NOT
telescope at the Observatorio del Roque de los Muchachos (La Palma).
Both sets of observations were carried out with the IAC-CCD camera. This
camera is equipped with a 1024 x 1024 Thomson CCD. The field of view was
{7{(') }.4} for the IAC80 and {2{(') }.4} for the NOT observations.
Different narrow band filters were used in both observations. At the
IAC80 a [O iii] lambda 5007 Angstroms (FWHM=30 Angstroms) and a
Hα + [N {ii}] (FWHM=100 Angstroms) were used. At the NOT
telescope, in addition to the same [O iii] filter, two Hα (FWHM=9
Angstroms) and [N {ii}] (FWHM=9 Angstroms) were used. Exceptional good
seeing conditions allowed an image quality of {0('') .4} in s ome of the
images. The catalog has been published in book form. Here as an example
we present some composite real color images of PNe of different
morphological classes, produced by combining the Hα + [N {ii}]
with red, and the [O {iii}] with green. References Balick B., 1987, AJ
94, 671 Schwarz H. E., Corradi R. L. M.,Melnick, J., 1992, AAS, 96, 23
Chu, Y.-H., Arendt, R., Jacoby, G.H., 1987, ApJS, 64, 529