0 Assigned ID: 1696 ----- Attempting Submission 1 (Wed Mar 21 23:46:34 GMT 2018) ----- HST Phase I Proposal 1696 (sdssj0234_midcycle25.apt) successfully submitted. Receipt: # 1696-1 For the best data quality, it is strongly recommended that the maximum number of allowed FP-POS positions is used when observing at a given COS CENWAVE setting. See full description for details. INEFFICIENT ORDERING OF FP-POS POSITIONS For the best data quality, it is strongly recommended that the maximum number of allowed FP-POS positions is used when observing at a given COS CENWAVE setting. See full description for details. INEFFICIENT ORDERING OF FP-POS POSITIONS 0 ----- Attempting Submission 1 (Wed May 23 07:47:55 GMT 2018) ----- FP-POS positions are being used in accordance with COS2025 policies. The detailed elemental composition of an exo-Pluto We have identified a new single, polluted, circumstellar disk-bearing white dwarf star first identified as a photometric white dwarf candidate in SDSS. SDSSJ0234-0406 is accreting extremely oxygen- and hydrogen-rich material that is otherwise depleted in all other rocky elements, suggesting that it is being polluted by a massive icy body. Similarities with the extrasolar Kuiper belt object-ingesting WD1425+540 suggest SDSSJ0234-0406 is being polluted by what could be an exo-Pluto analog. We propose COS FUV spectroscopic observations of SDSSJ0234-0406 that will allow us to confirm our interpretation and then obtain an exhaustive elemental composition for a Pluto-like body from another planetary system. These observations will address questions pertaining to the homogeneity of the formation and evolution of outer planetary systems and be a timely comparison to the New Horizons results for Pluto and eventually 2014 MU69. Our primary goal is to confirm the O-rich and rocky element-poor (Si, Fe) nature of SDSSJ0234-0406 and determine how much C, N, and S are present to place the origin of the accreted parent body. Our secondary goal is then to characterize additional elements. Modeling of absorption lines shows that the desired elements can be measured or sufficiently strongly constrained with observations in the 1130-1433 Angstrom range. We will perform medium spectral resolution ultraviolet spectroscopy with COS and the G130M grating to cover the 1130-1433 Angstrom range. In accordance with the COS2025 policies, we will only use two FP-POS positions (3 and 4). For the GALEX-measured FUV flux of SDSSJ0234-0406 (FUV AB magnitude of 17.27+/-0.035), we estimate how much time on source is necessary to obtain our desired S/N. It should be possible to obtain average S/N~15 in the 1130-1433 Angstrom wavelength range with total on-source exposure time of approximately 17,000 seconds. These estimates are made using the COS ETC assuming standard background parameters and with a white dwarf spectral energy distribution matched to the parameters and flux level of our target. A signal-to-noise ratio of ~15 for the 1130-1433 Angstrom wavelength range will enable detection or tight limits on the abundances of O, Fe, Si, C, N, and S. Such a signal-to-noise ratio will also enable the detection or constraint of other elements (e.g., aluminum, phosphorus, chromium, manganese, or nickel). Our requested time estimates for COS are increased assuming 20 minutes of instrument overhead (including all acquisition and exposure overheads as suggested in the COS manual) per visit and 6 minutes of observatory overhead per orbit (spacecraft acquisition). In sum, we request 7 orbits total for COS observations of SDSSJ0234-0406. Observations will be done in the TIME-TAG mode using TAG-FLASH wavelength calibration. SDSSJ0234-0406 is an ICRS object (SDSS position with less than 0.4" positional uncertainty), has measured GALEX UV fluxes, and is safe for the COS detectors in our desired setups. Planets and Planet Formation Solar System 6 false true false false false false SUPPORTED STAR DA DB DZ NO PHL1360 J2000 J2000 m_FUV = 17.3, m_NUV = 16.5 The scheduling data was generated by CASM 25.2. CASM was run in Phase I mode. COS/FUV Spectroscopic No No G130M 1291 /private/var/folders/0m/1rqjzh0n6nv2rddxlww1163m0000gn/T/OPVisit1656553184597030525.xml The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. COS/FUV observations of SDSSJ0234-0406 (Tic-Visit :proposal-id 15461 :visit-id "01" :proposal-version -1 :trans-version "20171009" :date "23-May-2018 00:12:01.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 165360 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15461 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15461 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2869 :al-overhead-at-end 0 :internal-dur-at-end 76 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15461 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2980 :al-overhead-at-end 0 :internal-dur-at-end 86 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15461 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2980 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) true 3 0 /Users/cmelis/observing/hst/cycle25/midcycle/phaseii/OP-cache/sdssj0234_midcycle25_phaseii-v02.xml The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. COS/FUV observations of SDSSJ0234-0406 (Tic-Visit :proposal-id 15461 :visit-id "02" :proposal-version -1 :trans-version "20171009" :date "23-May-2018 00:05:44.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 217552 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15461 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15461 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2869 :al-overhead-at-end 0 :internal-dur-at-end 76 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15461 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2980 :al-overhead-at-end 0 :internal-dur-at-end 86 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15461 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2980 :al-overhead-at-end 0 :internal-dur-at-end 86 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15461 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2980 :al-overhead-at-end 0 :internal-dur-at-end 379 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) true 4 0