----- Attempting Submission 1 (Mon Jun 18 23:09:05 GMT 2007) ----- Planetary Nebulae, Globular Clusters, and Binary Mergers Four planetary nebulae (PNe) have been found within 130 of the 150 globular clusters (GCs) of our Galaxy. This might not seem like many, but stellar evolution predicts that the old populations of these clusters should contain no PN at all! Observations of three of the four GC PNe show them to have peculiar characteristics, possibly indicative of a binary/merger origin. In particular two of the three observed GC PNe have masses which correspond to main sequence masses ~2-3 times the clusters' turn-off masses, sugesting mergers of two, or even three stars have taken place. One of the three observed PNe is H-deficient, a characteristic exhibited by only 5 out of hundreds of field PNe. H-deficient PNe have been associated with binarity. As usual, not all parameters for these three PNe are clean indications of their binary origin. In this proposal we ask to obtain WFPC2/WFC observations of the only GC PN that has never been observed before at high resolution and whose central star has never been detected. This objects could tip the balance toward a binary interpretation for the GC PNe or make us seriously reconsider our understanding of stellar evolution in old populations. HST is essential for the task since this PN is tiny and the clusters it lives in is crowded. Our request to use DD time for this proposal was encouraged by the Telescope Time Review Board after they denied an instrument change request for our cancelled ACS/WFC program. The denial resulted from a substantial change in observing strategy which was deemed too complex not to be reviewd by a TAC.
We will observe the central star of the planetary nebula JaFu 1 in the globular cluster Pal 6 using the WFPC2. For photometry of the central star, we will obtain 2x160 sec dithered exposures in F555W and F814W. To minimize CTE effects, we are placing the star at the WFALL position in WF3. The single orbit will be filled out with 2x500 sec in F656N, in order to obtain a narrow-band image of the surrounding planetary nebula in the light of H-alpha. The PN is small enough (about 6"x8") that the entire nebula will fall within WF3 when the central star is placed at the WFALL position. ISM AND CIRCUMSTELLAR MATTER 0 false 0.0 false false false false false false SUPPORTED STAR PLANETARY NEBULA CENTRAL STAR POPULATION II POST-AGB STAR [OIII]=5.8e-15; Ha=2.4e-14 (cgs/sq.arcsec; observed) PAL6-PN J2000 17 43 57.3800 -26 11 54.00 J2000 WFPC2 Imaging No F656N WFPC2 Imaging No F502N WFPC2 Imaging No F814W WFPC2 Imaging No F555W /var/tmp/OPVisit36028.xml (Tic-Visit :proposal-id 11308 :visit-id "01" :proposal-version -1 :trans-version "20070325" :date "18-Jun-2007 19:04:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11308 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11308 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2700 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 1 0 /var/tmp/OPVisit6514.xml