0 Assigned ID: 811 ----- Attempting Submission 1 (Fri Apr 10 20:52:06 GMT 2015) ----- HST Phase I Proposal 811 (coolDZ.apt) successfully submitted. Receipt: # 811-1 ----- Attempting Submission 2 (Fri Apr 10 20:55:05 GMT 2015) ----- HST Phase I Proposal 811 (coolDZ.apt) successfully submitted. Receipt: # 811-2 ----- Attempting Submission 3 (Fri Apr 10 22:24:35 GMT 2015) ----- 0 ----- Attempting Submission 1 (Fri Jul 03 12:06:51 GMT 2015) ----- The dawn of rocky planet formation The vast majority of all known planet host stars will eventually evolve into white dwarfs. With the parameter space of the known planetary systems ever increasing, it is now clear that a significant fraction of these systems will survive this evolution (including the solar system from Mars outwards). Equally, many of the known white dwarfs were once planet hosts, and some of them very likely still host the remnants of planetary systems. In fact, we already know the signposts of such evolved planetary systems: metal-pollution of the otherwise pristine H/He atmosphere of a white dwarf by accretion of planetary debris. The identification of the coolest and hence oldest metal-polluted white dwarfs opens the exciting potential to investigate the history of rocky planet formation in the Galaxy. Using the Sloan Digital Sky Survey, we are now discovering large numbers of such systems: white dwarfs that have accreted rocky bodies of at least the mass of Ceres, the largest asteroid known in the solar system, and that already finished their main-sequence life when the Earth was just being formed. Precise measurements of the system ages, and accurate chemical abundances of the planetary debris require improved model atmospheres and input physics to deal with the extremely dense atmospheres of these cool white dwarfs, which we have computed. Because the strongest absorption features lie in the near-ultraviolet, we request HST STIS observations of three systems spanning the relevant range of temperatures to test and calibrate our calculations. With those calibrations in hand, we will then be able to analyse the full sample using only the available optical data. The objective of these observations is to obtain NUV spectra of 3 cool metal-polluted white dwarfs covering different temperatures. This wavelength range is previously unobserved for objects of this type, and so line strengths in this region are not well known. Because the degree of absorption in this range leads to radiative backwarming of the optical spectra of these stars, our atmospheric models are currently not well calibratated, and so accuracy of calculated temperatures is model limited. The 3 objects cover a range of temperatures for these stars with the expected UV flux varying correspondingly. SDSS0956+5912 is the faintest object in the optical but has relatively bright UV flux as indicated by its GALEX NUV magnitude of 21.4. In contrast, SDSS1536+1247 is the brightest target in the optical (due to its proximity), but because it is much cooler, there is significant line blanketing in the UV and therefore has the lowest GALEX NUV magnitude of 22.4. Therefore, despite SDSS1536+1247 being the brightest object in the optical we require 4 orbits (rather than 2 for our other targets), to obtain the required signal-to-noise. The observations are fairly straightforward. Each target has one visit which starts with an acquistion. The target is then observed over thr required number of orbits with STIS-NUV, using the G230-L grating and 52x2 slit. EXTRA-SOLAR PLANETS 12 false true false false SUPPORTED STAR DZ NO J2000 J2000 GALEX_NUV = 21.4 STAR DZ NO J2000 J2000 STAR DZ NO J2000 J2000 GALEX_NUV =22.4 STIS/NUV-MAMA Spectroscopic No No G230L 2376 STIS/NUV-MAMA Spectroscopic No No G230L 2376 STIS/NUV-MAMA Spectroscopic No No G230L 2376 /home/astro/phujdu/Documents/proposals/HST_201504/OP-cache/14128-v01.xml The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14128 :visit-id "01" :proposal-version -1 :trans-version "20150609" :date "03-Jul-2015 12:10:33.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 818016 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14128 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14128 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3123 :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 3456 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14128 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3234 :al-overhead-at-end 0 :internal-dur-at-end 603 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3456 :pcs-gap 0 ) true 2 0 We use the 50CCD filter for the acquisition instead of the default F28X50LP as there is a nearby, somewhat fainter, red object - just to be on the safe side that STIS will acquire the brighter / bluer white dwarf target. Estimated total count rate (source + target) ~1600, to be a bit more conservative (e.g. higher than expected background level), we assumed twice that rate to calculate the BUFFER-TIME. Estimated total count rate (source + target) ~1600, to be a bit more conservative (e.g. higher than expected background level), we assumed twice that rate to calculate the BUFFER-TIME. /home/astro/phujdu/Documents/proposals/HST_201504/OP-cache/14128-v02.xml The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14128 :visit-id "02" :proposal-version -1 :trans-version "20150609" :date "03-Jul-2015 12:10:22.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 661424 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14128 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14128 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2877 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14128 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 0 :internal-dur-at-end 603 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210 :pcs-gap 0 ) true 2 0 Estimated total count rate (source + target) ~1600, to be a bit more conservative (e.g. higher than expected background level), we assumed twice that rate to calculate the BUFFER-TIME. Estimated total count rate (source + target) ~1600, to be a bit more conservative (e.g. higher than expected background level), we assumed twice that rate to calculate the BUFFER-TIME. /home/astro/phujdu/Documents/proposals/HST_201504/OP-cache/14128-v03.xml The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14128 :visit-id "03" :proposal-version -1 :trans-version "20150609" :date "03-Jul-2015 12:09:55.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 1392016 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14128 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14128 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2885 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14128 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2996 :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 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14128 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2996 :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 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14128 :visit-id "03" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2996 :al-overhead-at-end 0 :internal-dur-at-end 603 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 4 0