arXiv:astro-ph/0311552v1 25 Nov 2003 .Minr .Ksnr n .Skreds. Soker N. and Kastner, J. 2004 Meixner, XXX, M. Vol. Series, Conference III ASP Nebulae Planetary Asymmetric n o ioa n litcl nterlts ok hyal they work, latest their star In central elliptical. the and that bipolar found for 2002) ent (1993; elli therein al. references while et sta and stars Stanghellini 2003 from mass (Phillips derive progenitor higher of reference PNe from masses and circular arise 2000 from particular, bipolar arise progenitor, In al. morphologies different et masses. having scheme Manchado different PNe classification 1993; that morphological accepted studies al. a is several et produce The and Schwarz to quantify evolve. 1987; past star to the the difficult provi how is in PNe of which of picture and parameter morphology better models a The a theoretical have . to test the portunity of to opportunity dynamics the help foun the offers will be about PNe which can a of kinematics, catalogues etc.), study morphology, PNe masses The (like I). all parameters Paper with physical ( - basic list Galaxy (2003a A our in al. made of PNe. et been evolution new have surveys discover and Many to history interste therein). the formation references and of star 2000 history the enrichment beca in chemical interest as the great in of role are tant (PNe) Nebulae Planetary Galactic Introduction 1. Abstract. UK 9DL, SK11 [email protected] Cheshire Astronom Email: Macclesfield, & Manchester, Physics of of University Department Observatory, Bank Jodrell Em , Bryce Myfanwy Athens, Penteli, P. 36 GR-152 Paulou, [email protected] V. Observator & National Metaxa Astrophysics, I. & Astronomy of Institute Boumis Panayotis Plane Galactic Northern the in Nebulae Planetary New lntr eua Pe icvrdtruha [O an through discovered (PNe) Nebulae Planetary iesre nteGlci ug einwith region Bulge Galactic the in survey line ioa,rsetvl.6%o h on N rsn ring-li present ellipti PNe are round 9% compact. the and are 31% 37% of while while 63% (60%), st round morphological respectively. th are first bipolar, for Their them obtained of detail. most were in them that spectra study resolution to low order in as well as images oeta 0 bet,icuig4 e N.De H Deep PNe. new 45 including objects, 200 than more epeetde H deep present We 1 α +[N ii C mgso eetdnew selected of images CCD ] > l 0 o .O apeo PNe, of sample a On ). ocnr htround, that confirm so nttl edetected we total, In . udne,distances, bundances, tcldrv rmall from derive ptical itiuini differ- is distribution lrmdu swell as medium llar iii s fterimpor- their of use swt o mass low with rs 5007 ] nesadmore understand h ati order in past the rgntr with progenitors rmrhlg is morphology ir aebe made been have o N (Balick PNe for euiue al. et Beaulieu α hri) It therein). s +[N eu h op- the us de odetermine to d suggests udy nBoumis in d fAthens, of y estructure ke A ˚ e PNe new e y, emission ii , a and cal CCD ] ail: 2 Boumis & Bryce elliptical and bipolar PNe have different spatial distributions within the Galaxy and that they might belong to different stellar populations. Here, we present selected Hα+[N ii] images of new PNe showing the different morphological types found, and our first results concerning their morphology.

2. Observations

2.1. The [O iii] 5007 A˚ Survey The survey observations were performed during the 2000–2001 observing sea- sons, with the 0.3 m telescope at Skinakas Observatory in (Greece). We observed the regions 10o

2.2. Imaging & Spectroscopy Follow– up observations (images and spectra) were obtained with the 1.3 m telescope at the same site during 2001–2003. The images were performed in Hα+[N ii] in order to study the morphology of the PNe and also measure their angular extent while their low–resolution spectra confirmed their photoionized nature. All new PNe can be seen in Paper I and Boumis et al. (2003b; Paper II) while images of some of the new PNe are shown in Figure 1, where their different morphological classes can be seen. The image size is 65 arcsec on each side. North is at the top and east to the left.

3. Preliminary morphological results

The Hα+[N ii] images as well as the low resolution spectra of the newly discov- ered PNe were used for a more detailed morphological study. A morphological type was assigned to the new PNe according to Manchado et al. (2000). In most cases, a spherical well-defined shell (star-like or ring) was found, elliptical nebulae are also present while a small number appears to be bipolar. In partic- ular, 60 percent are round - with 63% of these presenting a ring–like structure (e.g. PTB34) and the remaining 37% being compact (e.g. PTB20) - 31% are elliptical (e.g PTB19) and 9% bipolar (e.g PTB7). Note that the morphological class of some PNe could not be distinguished clearly and even though these have been classified as round, the possibility that they are elliptical cannot be ruled out. Also, following the Manchado et al. (2000) classification, quadripolar PNe (e.g. PTB24) were included in the bipolar class. The electron density was found to be different for each morphological class. The median value for ellipticals is higher than that for the round and bipolar PNe. Also, a first indication shows New PNe in the Northern Galactic Plane 3

that the [N ii]/Hα and N/O ratios are higher for round than for elliptical PNe. However, the abundances in N/O and He generally showed low N/O and He, implying old progenitor stars. More analytical results are presented in Papers I, II. Acknowledgments. Skinakas Observatory is a collaborative project of the , the Foundation for Research and Technology-Hellas and the Max-Planck-Institut fur Extraterrestrische Physik.

References

Balick, B. 1987, AJ, 94, 671 Beaulieu, S. F., Freeman, K. C., Kalnajs, A. J., Saha, P. & Zhao, H. 2000, AJ, 120, 855 Boumis, P. & Papamastorakis, J. 2003, Proc.5th Hellenic Astron.Soc.Conf., in press1 Boumis, P., Palaiologou, E. V., Mavromatakis, F. & Papamastorakis, J. 2003, MNRAS, 339, 735 (Paper I) Boumis, P. et al. 2004, MNRAS, in preparation (Paper II) Manchado, A., Villaver, E., Stanghellini, L. & Guerrero M. 2000, in ASP Conf. Ser. 199, Asymmetrical Planetary Nebulae II. From Origins to Mi- crostructures, eds. Kastner et al., 17 Phillips, J. P. 2003, MNRAS, 340, 883 Schwarz, H. E., Corradi, R. L. M. & Stanghellini, L. 1993, IAU Symp 155, p. 214, eds. Weinberger and Acker, (Kluwer:Dordrecht) Stanghellini, L., Corradi, R. L. M. & Schwarz, H. E. 1993, ˚a, 279, 521 Stanghellini, L., Villaner, E., Manchado, A. & Guerrero, M. A. 2002, ApJ, 576, 285

1 http://atlas.astro.auth.gr/ helasmtg/2001/proceedings.htm 4 Boumis & Bryce

Figure 1. The different morphological PNe classes can be seen in this figure. In particular PTB14 and PTB20 are round/compact (RC), PTB13 and PTB34 are round/ring (RR) while PTB19 and PTB31 are elliptical (E) and PTB7 and PTB24 are bipolar (B) with the latter presenting a quadripolar morphology.