0 Assigned ID: 505 ----- Attempting Submission 1 (Fri Feb 24 17:31:05 GMT 2012) ----- HST Phase I Proposal 505 (west2.apt) successfully submitted. ----- Attempting Submission 2 (Fri Feb 24 20:16:31 GMT 2012) ----- HST Phase I Proposal 505 (west2.apt) successfully submitted. ----- Attempting Submission 3 (Fri Feb 24 20:17:18 GMT 2012) ----- Exposure time in the second F658N exposure has been increased 1732886892 ----- Attempting Submission 1 (Fri Jun 22 20:57:06 GMT 2012) ----- ----- Attempting Submission 2 (Mon Jul 23 16:08:53 GMT 2012) ----- ----- Attempting Submission 3 (Fri Sep 21 18:50:44 GMT 2012) ----- ----- Attempting Submission 4 (Thu Sep 27 22:23:52 GMT 2012) ----- Visit Planner has been run. Westerlund 2, top to bottom: how massive star clusters form. Massive stellar clusters are the main indicators of star formation activity in the distant universe, still their origin and evolution is only partially understood. We have demonstrated that combining deep high resolution optical and IR photometry is a powerful method to investigate the initial phases of massive stellar clusters. We are now proposing to obtain deep, high resolution ACS and WFC3 observations designed to individually resolve and measure stars in Westerlund 2 (Wd2), one of the youngest and most massive clusters in the Milky Way, from the upper mass cut-off down to the hydrogen-burning limit. Wd2 is quite unique, because it is close (8kpc), young (<2Myr), massive (>10^4 Mo) and not well studied. Yet, it is perfectly suitable to investigate how it formed, since neither stellar evolution nor cluster dynamics have had enough time to significantly affect its initial conditions. We propose to determine its mass function, which will well approximate its IMF, establish whether primordial mass segregation is present, characterise the population of pre-Main Sequence stars that have been found by Spitzer, and - as a added bonus - take a high resolution view of the surroundings of WR20a, a very massive eclipsing WR binary that might have been ejected from the cluster center. Second epoch observations in two years will allow us to accurately identify the Wd2 cluster members, and will establish the presence of additional walkaway stars, in addition possibly to WR20a. Because high resolution, high dynamic range, and PSF stability - necessary for the astrometric part - are absolute requirements to complete this project, this study can only be done with HST. Observations are organized in two visits, the first visit consists of 2 orbits, for a total of 12 ACS/WFC exposures in the optical filters F555W, F814W and F658N. Dithering is perfomed via the POS TARG keyword and is designed to fill the gap between the 2 ACS detectors and avoid multiple hits of the same bad column and bad pixels by the same source. The second visit (called IR-mosaic) consists of a 4 poinings mosaic using the WFC3/IR camera in the filters F110W, F160W and F128N. For each tile a 4 point dithering is performed using the POS TARG keyword. The dithering has been designed to avoid multiple hits of the same source on the same bad column, or other detector imperfections. RESOLVED STELLAR POPULATIONS 12 false 0.0 0.0 false false false false SUPPORTED STELLAR CLUSTER STAR FORMING REGION This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W ACS/WFC Imaging No No F658N WFC3/IR Imaging No No F125W WFC3/IR Imaging No No F128N WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F814W The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. /Users/sabbi/WFC3/CI/CY20/OP-cache/13084-v01.xml (Tic-Visit :proposal-id 13038 :visit-id "01" :proposal-version -1 :trans-version "20120802" :date "27-Sep-2012 18:21:55.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 3410688 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13038 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13038 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3142 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3491 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13038 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3219 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3491 :pcs-gap 0 ) true 2 0 Same orient constraint links visits (08 09 10 11) The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13038 :visit-id "08" :proposal-version -1 :trans-version "20120604" :date "21-Sep-2012 14:48:54.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2071696 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13038 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13038 :visit-id "08" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3120 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3491 :pcs-gap 0 ) true 1 0 Same orient constraint links visits (08 09 10 11) The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13038 :visit-id "09" :proposal-version -1 :trans-version "20120604" :date "21-Sep-2012 14:48:57.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2071696 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13038 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13038 :visit-id "09" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3120 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3491 :pcs-gap 0 ) true 1 0 Same orient constraint links visits (08 09 10 11) The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13038 :visit-id "10" :proposal-version -1 :trans-version "20120604" :date "21-Sep-2012 14:48:59.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2071696 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13038 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13038 :visit-id "10" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3120 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3491 :pcs-gap 0 ) true 1 0 Same orient constraint links visits (08 09 10 11) The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13038 :visit-id "11" :proposal-version -1 :trans-version "20120604" :date "21-Sep-2012 14:49:01.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2071696 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13038 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13038 :visit-id "11" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3120 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3491 :pcs-gap 0 ) true 1 0