Over the past few years, it has become increasingly clear that the most plausible scenario to explain the infrared excess observed at ~30 white dwarfs is accretion from rocky planetary material - suggesting that these white dwarfs may have had, or may still have terrestial planets as well. This hypothesis is corroborated through the detection of volatile-depleted abundance patterns in the photospheres of these white dwarfs. We are carrying out a large COS snapshot survey of 150 white dwarfs, with the aim to determine the fraction of remnants of planetary systems around young (20-200Myr) white dwarfs. At the time of writing, we have observed 94 white dwarfs, and find pollution by Si, one of the major constituents of the Earth, in ~25% of them. In about a dozen stars, we detect multiple (up to nine) different elements, and show that their abundance pattern is broadly consistent with that of bulk-Earth: extremely volatile depleted, in particular in C/Si. However, there are two exceptions: WD1013+256 and WD1647+375 show strong lines of both Si and C. We have ruled out accretion from the wind of a nearby low-mass companion, and the only explanation is accretion of planetary debris that is significantly richer in C than the bulk Earth. This discovery is of substantial significance within the current discussion on variations in the exo-planet chemistry. We propose to re-observe these two white dwarfs, doubling the signal-to-noise ratio with respect to our very short Snapshot spectra, to and to determine the abundances of additional elements, including Fe, O, and possibly Ni and N. These COS FUV observations are a follow-up of three targets that were observed in Cycle 18/19 as part of a COS snapshot survey. We will use the same setup (G130M@1291A), but will use all four FP-POS positions to properly account for fixed pattern noise, and increase the total exposure time per target such that we achieve a S/N~30-40 across the entire wavelength range, i.e. in particular also in the wings of the Ly alpha absorption, where several weak, sharp metal absorption lines of interest are located. Positions and proper motions for all three targets were taken from the PPMXL catalogue, and the Cycle 18/19 observations were successful without the use of an ACQ/SEARCH. We follow here the same strategy. EXTRA-SOLAR PLANETS 12 false 0.0 0.0 false false false false SUPPORTED STAR DA White dwarf, Teff=19000 logg=7.50. This star has been observed on 2011-12-23 with the same setup (COS/G130M), see data set LBOVNP. The formal error on the position in 2012/13 based on the uncertainty in the historic position and proper motion is ~0.3". The COS observations were successfully acquired without a ACQ/SEARCH. This is also one of the STIS standard stars, and has been observed many times with the G140L / G230L. J2000 J2000 STAR DA White dwarf, Teff=21990 logg=8.00. This star has been observed on 2011-04-24 with the same setup (COS/G130M), see data set LBIY9C. The formal error on the position in 2012/13 based on the uncertainty in the historic position and proper motion is ~0.3". The COS observations were successfully acquired without a ACQ/SEARCH. J2000 J2000 STAR DA White dwarf, Teff=21980 logg=7.89. This star has been observed on 2011-10-05 with the same setup (COS/G130M), see data set LBOVAA.The formal error on the position in 2012/13 based on the uncertainty in the historic position and proper motion is ~0.3". The COS observations were successfully acquired without a ACQ/SEARCH. J2000 J2000 COS/FUV Spectroscopic No No G130M 1291 COS/FUV Spectroscopic No No G130M 1291 COS/FUV Spectroscopic No No G130M 1291 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12869 :visit-id "01" :proposal-version -1 :trans-version "20120615" :date "19-Jun-2012 12:37:09.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 487168 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12869 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12869 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3302 :al-overhead-at-end 0 :internal-dur-at-end 404 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3635 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12869 :visit-id "02" :proposal-version -1 :trans-version "20120615" :date "19-Jun-2012 12:29:16.0" :trans-errors '(:WARNINGS 0 :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 896016 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12869 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12869 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2882 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12869 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3031 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12869 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3031 :al-overhead-at-end 0 :internal-dur-at-end 395 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3253 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12869 :visit-id "03" :proposal-version -1 :trans-version "20120615" :date "19-Jun-2012 12:42:22.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 765504 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12869 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12869 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2954 :al-overhead-at-end 0 :internal-dur-at-end 395 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3287 :pcs-gap 0 ) true 1 0