Download tables: tables.xlsx

Planetary nebulae (PNe) are amongst the most complex and varied of celestial objects, displaying a wide range of shapes and colours that are difficult to explain. Using the FORS2 instrument - mostly when no other observations can be performed - we have started to build up a homogeneous morphological catalogue of deep two-colour narrowband images of newly discovered PNe.

The availability of the MASH catalogue, which provides us with the necessary homogeneous sample to perform a detailed morphological classification, coupled to the great collecting power of the Very Large Telescope (VLT), prompted us to start POPIPlaN - the Paranal Observatory Project to Image Planetary Nebulae.

This new catalogue will by no means duplicate any existing one, but on the contrary provide much needed material required for follow-up studies. These will include, but not be limited to: derivation of statistics regarding various shapes, such as LIS, rings and jets; determination of binarity and the relationship between the presence of certain morphological traits and a central binary; studies of the interaction of PN envelopes with the ISM; analysis of the link between PNe and symbiotic stars; deeper and more detailed study with HST or adaptive optics instrumentation; kinematical studies of the newly discovered structures; and understanding the formation of the nebula and the timing of the formation of jets.

POPIPlaN, was specifically designed as a filler for Unit Telescope 1 (UT1) at the VLT, to be carried out in service mode by Paranal staff. The observations are done in twilight, or under thin (THN) or thick (THK) clouds. We have analysed the weather statistics for the last two years and find that there are THK conditions on at least part of 15 nights per period that could be used by our programme, as well as other occasions with THN conditions and strong wind from the north. Although the majority of our programme was done with the MIT CCD of FORS2, some of the observations were also performed when the blue E2V CCD was installed in FORS2 and nothing else could be observed.

For each object, we took images, with a sampling of 0.25 arcsecond (2 x 2 pixel binning), in Ha+[Nii] (with the H_Alpha+83 FORS2 filter) and [Oiii] (Oiii+50 filter), and exposure times between 240 s and 450 s, the majority being 300 s. For some objects, we have also obtained images in [Oii] 3727 Å and [Siii] 6723 Å as well as in the B- and I-broadband filters in order to help identify the central star. The constraints were set such that images could be taken when the seeing was below 1.2 arcseconds, or 1.4 arcseconds for a small subset, but in reality, most of the images have been taken under much better seeing conditions. Some of our images have a full width at half maximum of about 0.4 arcseconds!


The completion of this project would have not been possible without the financial support from the RAS Travel Grant, and the University of Manchester Work Experience Bursary/Travel Awards. For that reason, I am (Peter Pedersen, catalogue designer) incredibly grateful for everything that I have learnt, as well for the amazing and unique experiences that ESO Chile have given me.