Most stars in our Galaxy, including all known planet hosts, will end or have already ended their lives as white dwarfs, dense stellar remnants sustained by electron degeneracy. Here, we propose to obtain COS far-ultraviolet spectroscopy of three pulsating hydrogen-atmosphere (DA) white dwarfs (ZZ Ceti stars) that for which we are obtaining Kepler short-cadence data. Far-ultraviolet spectroscopy of white dwarfs, covering the H2/H2+ quasi-molecular satellites around 1400A and 1600A, is essential to determine accurate atmospheric parameters, and precision asteroseismology of white dwarfs has the potential to probe in detail the structure of their cores and envelopes that is not possible in any other way. A succesful asteroseismologial analysis requires, however, the correct identification of the pulsation modes. Because ZZ Ceti stars have typically only few large-amplitude modes, the mode identification based on their optical light curves is often ambiguous. Because the ratio of ultraviolet-to-optical pulsation amplitudes depends strongly on the pulsatoin mode, our COS data will also enable us to identify the pulsation modes in the Kepler light curves of these three stars. The unique combination of HST and Kepler observations will enable to investigate the atmospheric and internal structure of three white dwarfs with an unprecedented accuracy. The proposed research is part of the PI's doctoral thesis. The aim of the observation is to obtain a far-ultraviolet spectrum of a ZZ Ceti (pulsating DA white dwarf) in the Kepler field. The sequence is straight-forward: an imaging target acquisition, followed by G140L spectroscopy using all four FP-POS positions. As this is part of Ms Greiss PhD work, it would be very helpful if the observations could be scheduled early in Cycle 21. Ms Greiss plans to submit her Thesis by February 2014. HOT STARS Default false true false false false SUPPORTED STAR ZZ CETI STAR J2000 J2000 STAR ZZ CETI STAR J2000 J2000 STAR ZZ CETI STAR J2000 J2000 COS/FUV Spectroscopic No No G140L 1105 COS/FUV Spectroscopic No No G140L 1105 COS/FUV Spectroscopic No No G140L 1105 The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13430 :visit-id "01" :proposal-version -1 :trans-version "20130502" :date "26-Jun-2013 17:33:29.0" :trans-errors '(:WARNINGS 0 :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 652384 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13430 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13430 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2942 :al-overhead-at-end 0 :internal-dur-at-end 95 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3287 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13430 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3065 :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 3287 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13430 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3065 :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 3287 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13430 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3065 :al-overhead-at-end 0 :internal-dur-at-end 452 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3287 :pcs-gap 0 ) false 4 0