0 Assigned ID: 292 ----- Attempting Submission 1 (Thu Apr 06 20:19:50 GMT 2017) ----- 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. 0 ----- Attempting Submission 1 (Mon Jul 17 03:57:44 GMT 2017) ----- This is required by the COS2025 policies. Is SDSSJ195750.83+340404.4 accreting a planetary core? White dwarf stars are now known to regularly accrete material from their extant planetary systems. We have identified a new polluted white dwarf star that is accreting extremely iron-rich material, suggesting that it is being polluted by the core of a massive, differentiated rocky body. We propose COS FUV spectroscopic observations of SDSSJ1957+3404 that will allow us to peer into the heart of Earth-like rocky exoplanets. These observations will address questions pertaining to terrestrial planet structure and formation processes and the question of what mixture of elements is responsible for Earth's under-dense outer core. Our primary goal is to confirm the Fe-rich nature of SDSSJ1957+3404 and simultaneously ensure that the Fe originates from an O-poor core-like environment. 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 NUV flux of SDSS J1957+3404 (NUV AB magnitude of 16.66+/-0.03) and FUV-NUV colors for comparable temperature white dwarf stars we estimate the FUV AB magnitude to be 16.5 (GALEX observations of SDSS J1957+3404 were performed after the failure of the FUV channel, hence why only an NUV measurement is available). With such a magnitude, 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 4,000 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 oxygen and iron. Such a signal-to-noise ratio will also enable the detection or constraint of other elements (e.g., carbon, aluminum, phosphorus, sulfur, 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 2 orbits total for COS observations of SDSS J1957+3404. Observations will be done in the TIME-TAG mode using TAG-FLASH wavelength calibration. SDSSJ1957+3404 is an ICRS object (SDSS position with less than 0.4" positional uncertainty), has a measured GALEX UV flux, and is safe for the COS detectors in our desired setups. Planets and Planet Formation Stellar Physics 6 false false true false false false false SUPPORTED STAR DA NO SDSSJ195750.83+340404.4 J2000 J2000 GALEX NUV = 16.66 COS/FUV Spectroscopic No No G130M 1291 The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. COS/FUV observations of SDSSJ1957+3404. 1533122338000 165.8203549648028 (Tic-Visit :proposal-id 15080 :visit-id "01" :proposal-version -1 :trans-version "20170613" :date "15-Jul-2017 14:35:49.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 200144 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15080 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15080 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2907 :al-overhead-at-end 0 :internal-dur-at-end 124 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3240 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15080 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3018 :al-overhead-at-end 0 :internal-dur-at-end 341 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3240 :pcs-gap 0 ) true 2 0 /private/var/folders/bl/s7q0tqnn5gbcbyvcfnrhj2rh0004nc/T/OPVisit7895953194075503196.xml THis is a HOPR repeat of failed visit 01 (Tic-Visit :proposal-id 15080 :visit-id "Z1" :proposal-version -1 :trans-version "20180409" :date "09-Aug-2018 14:54:37.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 200144 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15080 :visit-id "Z1" :obset-id "Z1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15080 :visit-id "Z1" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2908 :al-overhead-at-end 0 :internal-dur-at-end 124 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3240 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15080 :visit-id "Z1" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3018 :al-overhead-at-end 0 :internal-dur-at-end 341 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3240 :pcs-gap 0 ) true 2 1