Background and first results from the new AAO/UKST H survey

First discoveries from the H survey

As an example of the impact that this survey can have for our study of the galaxy we present in figure 3 four examples of new, resolved planetary nebulae (PNe). They were discovered by one of us (QAP) from simple visual scrutiny of some of the first 3 hour H exposures. They were confirmed as new discoveries by cross-checking with SIMBAD and the on-line Strasbourg-ESO catalogue of Planetary Nebulae (Acker et al. 1992) and the Acker supplement (Acker et al. 1996). These new PNe are invisible or barely detectable on previous deep standard R-band exposures of the field but are easily found on the new H exposures. Follow-up visual searches of 10 new 3 hour H exposures by QAP and M.Hartley have found about 30 new PNe candidates. If this frequency is replicated throughout the survey then about 450 new optically detected/discovered resolved PN can be expected. This can be compared with the currently know in the galaxy (both hemispheres) based on entries in the Acker catalogues. Simple visual scanning of the survey films could significantly increase the number of Southern Galactic Plane PN. Planned SuperCOSMOS scans of these films would undoubtedly pick-up many more unresolved or barely resolved candidates for further study via comparison with the equivalent `continuum' short-red exposures which have similar (slightly shallower) depth.

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Figure 3: Four new PNe discovered on 3 hour H survey exposures. The top left and right PNe were discovered on exposure HA17614 (field 334). The bottom left PNe is from HA17617 (field 226) and bottom right from HA17619 (field 392). Each plot is arcminutes in size

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