0 Assigned ID: 737 ----- Attempting Submission 1 (Fri Apr 10 20:00:56 GMT 2015) ----- While a majority of the science can be completed at any roll angle, in the proposal description I have listed the "optimal" roll angles that will allow us to make the best use of overlap with archival data. I did not include any roll angle restrictions in the APT fields. Also, since I am a first time user, it would be helpful if someone experienced with WFC3 globular cluster observations could verify the observing strategy, including the dither position offsets. EDIT: 10/01/2015: I have added the "BLADE=A" option for all 8 short (10 sec) exposures in the program. I also shortened the F814W-Long exposures by 2 seconds in every orbit to accomodate the small increase in overhead. 601876302 ----- Attempting Submission 1 (Thu Jul 23 23:41:28 GMT 2015) ----- ----- Attempting Submission 2 (Thu Oct 01 18:35:35 GMT 2015) ----- Recent work combining HST photometry and ground-based spectroscopy has led to a renaissance in our understanding of Galactic globular clusters. The peculiar large light element abundance variations, discovered nearly 40 years ago by spectroscopy, hid in plain sight what HST finally revealed as a globular cluster's signature of formation: the existence, within a single globular cluster, of multiple populations with unique chemistry that trace out discrete photometric sequences. HST photometry and ground-based spectroscopy have revealed the existence of a new globular cluster class. These "anomalous" clusters are differentiated from normal globular clusters by exhibiting large (>0.1 dex) intrinsic metallicity dispersions, complex sub-giant branches, and correlated [Fe/H] and s-process abundances. Omega Centauri is the most famous and extreme example of this new class. Our new high-resolution ground-based spectroscopy demonstrates that NGC 6273, a largely unexplored but massive globular cluster, also exhibits the chemical characteristics of an anomalous cluster. Similar to Omega Cen, NGC 6273 possesses at least 2-3 stellar populations with very different [Fe/H] and s-process abundances; however, further analyses of this cluster are hindered by bulge field star contamination and strong differential reddening. Therefore, we are proposing to combine new WFC3 and archival WFPC2 data to photometrically trace the cluster's populations and isolate cluster members with proper motion cleaning. The HST photometry provides information about population ratios, radial distributions, and formation scenarios that are not possible to obtain by any other means. The observations for this project consist of multiple exposures with multiple filters centered on the Galactic globular cluster NGC 6273 (M19). We are using the WFC3 instrument and the F336W, F438W, F555W, and F814W filters. The observations cover 4 orbits, and we have setup each orbit to have a different small dither position (for PSF sampling; i.e., 1 orbit per dither position). The beginning and end of each orbit consist of a "short" exposure in either the F438W, F555W, or F814W filters. There should be one F555W short exposure per orbit and one F438W or F814W short exposure every other orbit (i.e., F555W short is observed 4 times and F438W/F814W are observed a total of two times each). Every orbit also contains "long" exposures for each of the F336W, F438W, F555W, and F814W filters. There is also a "medium" exposure for F336W that immediately follows each long F336W exposure. These are taken in each orbit so that every long/medium exposure is taken at all four dither point positions. The goal of the short/long pattern is to get good photometry for stars ranging from ~V=13.5-23. We will be matching these new observations to archival observations taken with WFPC2 (GO-7470 and GO-8718). Since the WFC3 field-of-view is larger than WFPC2, the roll angle is not too critical. However, if possible we would prefer to match as closely as possible with the GO-7470 and GO-8718 orientation. Based on the Aladin previewer, the best orientations seem to be roll angles between 0-120 degrees, 170-195 degrees, 277-290 degrees, and 350-360 degrees. If this is too restrictive, any roll angle will still permit us to complete a majority of the science goals. RESOLVED STELLAR POPULATIONS 12 false false false false AVAILABLE STELLAR CLUSTER BULGE GLOBULAR CLUSTER NGC6273 J2000 J2000 WFC3/UVIS Imaging No No F336W WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F555W WFC3/UVIS Imaging No No F814W 1443724329118 The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. /tmp/OPVisit7855547819582742689.xml (Tic-Visit :proposal-id 14197 :visit-id "01" :proposal-version -1 :trans-version "20150609" :date "01-Oct-2015 11:32:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 8084992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14197 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14197 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2896 :al-overhead-at-end 125 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3229 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14197 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3007 :al-overhead-at-end 125 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3229 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14197 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3007 :al-overhead-at-end 125 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3229 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14197 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3007 :al-overhead-at-end 125 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3229 :pcs-gap 0 ) true 4 0 Set "BLADE=A" with STScI approval. Set "BLADE=A" with STScI approval. Set "BLADE=A" with STScI approval. Set "BLADE=A" with STScI approval. Set "BLADE=A" with STScI approval. Set "BLADE=A" with STScI approval. Set "BLADE=A" with STScI approval.