0 Assigned ID: 353 ----- Attempting Submission 1 (Fri Apr 10 04:05:04 GMT 2015) ----- HST Phase I Proposal 353 (APTKaliraiUVWDs.apt) successfully submitted. Receipt: # 353-1 ----- Attempting Submission 2 (Fri Apr 10 17:15:02 GMT 2015) ----- HST Phase I Proposal 353 (APTKaliraiUVWDs.apt) successfully submitted. Receipt: # 353-2 ----- Attempting Submission 3 (Fri Apr 10 23:48:49 GMT 2015) ----- HST Phase I Proposal 353 (APTKaliraiUVWDs.apt) successfully submitted. Receipt: # 353-3 0 ----- Attempting Submission 1 (Thu Jul 23 12:39:34 GMT 2015) ----- We propose a 5 orbit HST program to acquire UV imaging at the center of the massive globular cluster NGC 362, in order to directly measure the rate of diffusion of stars through its core. This measurement will overcome a major observational barrier; that the dynamical time scale for two-body relaxation in the core of a globular cluster is typically much shorter than the age of the population, and so mass segregation in the cluster occured billions of years ago. Our novel technique aims to resolve this dynamical evolution by using the full power of WFC3's exquisite UV sensitivity at <0.3 microns combined with its high spatial resolution. We will uncover ~1000 newly formed stellar remnants - white dwarfs - in the center of the globular cluster and track how their spatial distribution changes as they get "older" on the cooling sequence. Having just experienced a significant episode of mass loss, the youngest white dwarfs with ages <10s of Myr will still be moving slowly like their 0.8 Msun progenitors, whereas the "older" white dwarfs that have been cooling for >100s of Myr will be fully relaxed. To "watch" this dynamical evolution and directly measure the diffusion coefficient, we have selected the very populous globular cluster NGC 362. The cluster is nearby with low reddening, has moderate concentration, and has a theoretical expected relaxation timescale of 60 Myr in its core, perfect to split the young and old white dwarfs that we can observe with Hubble. We are obtaining UV imaging with WFC3/UVIS in F225W and F275W of the core of NGC 362, and parallel ACS imaging in F435W and F555W of an outer field. The goal of the program is to measure the spatial distribution of newly formed white dwarfs and compare them to "older" remnants. Although both populations have the same mass, the newly formed remnants were much heavier less than one relaxation time ago. The difference will constrain the diffusion constant due to dynamical relaxation. For the WFC3/UVIS observations, we place the core of the globular cluster near the center of the WFC3 field and obtain 1 short and 4 long (dithered) exposures in each orbit. Post flash has been added to ensure 12 e- in each exposure to mitigate CTE. The parallel field will image a part of the cluster at larger radii for additional constraints on the spatial distribution of cool white dwarfs. All observations require a standard dither, implemented through POSTARGs. We have added an ORIENT constraint to ensure that the field nicely overlaps the archival F275W observations that will be coadded with this data. RESOLVED STELLAR POPULATIONS 12 false true false false SUPPORTED STELLAR CLUSTER GLOBULAR CLUSTER This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F275W ACS/WFC Imaging No No F435W ACS/WFC Imaging No No F555W 1437654615245 /Users/jkalirai/Desktop/Cycle23stuff/OP-cache/PhaseIIKaliraiUVWDs14155-v01.xml The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14155 :visit-id "01" :proposal-version -1 :trans-version "20150609" :date "23-Jul-2015 08:30:14.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 12903216 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14155 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14155 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3228 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3596 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14155 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3346 :al-overhead-at-end 117 :internal-dur-at-end 352 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3596 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14155 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3345 :al-overhead-at-end 117 :internal-dur-at-end 352 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3596 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14155 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3351 :al-overhead-at-end 117 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3596 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14155 :visit-id "01" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3352 :al-overhead-at-end 117 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3596 :pcs-gap 0 ) true 5 0