13430( 2) - 26-Jun-2013 18:56:21 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13430 Version: 2 Check-in Time: 26-Jun-2013 18:56:21 STScI Edit Number: 1 Title The temperatures, masses and pulsation modes of three ZZ Cetis in the Kepler field ------------------------------------------------------------------------------------ Type Cycle GO 21 ------------------------------------------------------------------------------------ Investigators Contact? PI: Ms. Sandra Greiss The University of Warwick Y CoI: Prof. Boris T. Gaensicke The University of Warwick N CoI: Prof. Detlev G. Koester Universitat Kiel N CoI: Mr. JJ Hermes University of Texas at Austin N ------------------------------------------------------------------------------------ Abstract 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. ------------------------------------------------------------------------------------ Observations Description ------------------------ 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. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments 13430( 2) - 26-Jun-2013 18:56:21 - [ 2] ------------------- 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. ------------------------------------------------------------------------------------ 13430( 2) - 26-Jun-2013 18:56:21 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 KIC-4552982 STAR, ZZ CETI STAR RA=19H16M43.8240S +/- 0.1", J2000 V = 17.6 +/- 0.1 DEC=+39D38'49.39" +/- 0.1" Reference Frame: ICRS Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.001818206579022318 0.0499 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 KIC-4552982- STAR, ZZ CETI STAR RA=19H16M43.8240S +/- 0.1", J2000 V = 17.6 +/- 0.1 COPY DEC=+39D38'49.39" +/- 0.1" Reference Frame: ICRS Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.001818206579022318 0.0499 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 KIC-4552982- STAR, ZZ CETI STAR RA=19H16M43.8240S +/- 0.1", J2000 V = 17.6 +/- 0.1 COPY-1 DEC=+39D38'49.39" +/- 0.1" Reference Frame: ICRS Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.001818206579022318 0.0499 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 13430( 2) - 26-Jun-2013 18:56:21 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 KIC-4552982 COS/NUV ACQ/IMA PSA MIRRORA 1 9 S (9 S) GE ------------------------------------------------------------------------------------------------------------------------------------ 2 KIC-4552982 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=1500, FLASH=YES, 1 2603 S G FP-POS=1 (2603 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 KIC-4552982 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=1500, FLASH=YES, 1 3001 S G FP-POS=2 (3001 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 KIC-4552982 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=1500, FLASH=YES, 1 3001 S G FP-POS=3 (3001 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 KIC-4552982 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=1500, FLASH=YES, 1 3001 S G FP-POS=4 (3001 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ KIC-4552982 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE KIC-4552982 2 COS/FUV TIME-TA PSA G140L 1105 none none none none 1 N/A G KIC-4552982 3 COS/FUV TIME-TA PSA G140L 1105 none none none none 2 N/A G KIC-4552982 4 COS/FUV TIME-TA PSA G140L 1105 none none none none 3 N/A G KIC-4552982 5 COS/FUV TIME-TA PSA G140L 1105 none none none none 4 N/A G 13430( 2) - 26-Jun-2013 18:56:21 - [ 5] Summary Form for Proposal 13430 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1500, FLASH=YES, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names KIC-4552982 ------------------------------------------------------------------------------------------------------------------------------------