15068( 4) - 14-Dec-2018 15:19:04 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15068 Version: 4 Check-in Time: 14-Dec-2018 15:19:04 STScI Edit Number: 2 Title A Detailed Study of Rocky Planetary Material in the Hyades ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jay Farihi University College London Y CoI: Prof. Boris T. Gaensicke The University of Warwick Y CoI: Dr. Seth Redfield Wesleyan University N CoI: Prof. Detlev G. Koester Universitat Kiel N CoI: Prof. Ben M. Zuckerman University of California - Los Angeles N ------------------------------------------------------------------------------------ Abstract The Hyades is the nearest open cluster, relatively young, and containing numerous A-type stars. Its youth, distance, and metallicity make it an ideal site to study planet formation around 2-3 Msun stars, and in a dynamically challenging environment. During our HST COS Snapshot, we discovered the ongoing accretion of Si-rich and C-deficient material in two white dwarf Hyads. The lower limit Si/C ratios determined from these 400s exposures indicate the material is more C-depleted than in chondritic meteorites, the most primitive rocks in the Solar System. Our 2013 Keck discovery of metal pollution in a third Hyades white dwarf indicates that planet formation is common in the cluster. Together, these three stars indicate that substantial minor bodies persist at several AU or more, and provide an unprecedented opportunity for a detailed study of rocky exoplanet precursors in a cluster environment. We propose to obtain detailed abundances of the planetary debris at these three polluted Hyads, which requires a modest investment of observatory time. The mass ratios between C, O, Mg, and Si are accurate indicators of the temperature and orbital regions where the parent bodies formed, their water and volatile contents. We will also detect Al and Fe, which are key indicators of differentiation and giant impacts among planetary embryos. Our proposed observations will provide legacy value for planet formation models, and especially those in cluster enviroments. These observations cannot be done from the ground or at optical or longer wavelengths, and must be carried out by HST in the ultraviolet. ------------------------------------------------------------------------------------ Observations Description ------------------------ In previous G130M COS observations, we detected photospheric metal contamination in these two Hyades white dwarfs, demonstrating that they accrete planetary debris. Here, we will obtain much deeper ultraviolet spectra spanning a wider 15068( 4) - 14-Dec-2018 15:19:04 - [ 2] wavelength range, probing for additional elements (C, Fe, Al, O, Mg). * WD0421+162: we obtained a short (400sec) COS G130M@1291A spectrum as part of our snapshot survey. Critical lines are at 1152A, 1260/65A, ~1290-1340A, ~1390-1403A. Because of the COS 2025 strategy, we will not be able to execute the observions @ 1291A with all FP-POS settings. To mitigate this, we will use one orbit @1291A, using FP-POS 3/4, and one orbit @1222A, using FP-POS 3/4, combining those two settings will provide particularly good coverage of the O I 1152A line. In addition, we will obtain COS G160M spectroscopy (Al 1670A) and STIS G230M (Mg 2800A). * WD0437+138: we obtained good G130M spectra as part of program 14597, here we will obtain COS G160M and STIS G230M spectroscopy. ------------------------------------------------------------------------------------ 15068( 4) - 14-Dec-2018 15:19:04 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 WD0421+162 STAR, DA RA=04H23M55.7040S +/- 0.1", J2000 V = 14.283 +/- 0.046 GALEX FUV=13.75836 DEC=+16D21'15.15" +/- 0.1" GALEX NUV=13.89075 Reference Frame: ICRS Extended: NO Comments: White dwarf in the Hyades, d=47pc, Teff=19322K, logg=8.10. Observed with COS/G130M: LBIYA8010 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.007941310838485507 -0.032299999999999995 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 WD0437+138 STAR, DA RA=04H40M23.8770S +/- 0.1", J2000 V = 14.924 +/- 0.030 GALEX FUV=15.43189 DEC=+13D58'45.97" +/- 0.1" GALEX NUV=14.84796 Reference Frame: ICRS Extended: NO Comments: White dwarf in the Hyades, d=45pc, Teff=15120K, logg=8.25 Observed with COS/G130M: LDAO08010 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0064648047435573635 0.09409999999999999 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 15068( 4) - 14-Dec-2018 15:19:04 - [ 4] Visit: 02 (WD0421+162 COS) 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 WD0421+162 COS/FUV ACQ/PEA PSA G130M 1291 1 2 S (2 S) KXD ------------------------------------------------------------------------------------------------------------------------------------ 2 WD0421+162 COS/FUV ACQ/PEA PSA G130M 1291 STEP-SIZE=0.9, NUM-POS=5, 1 2 S (2 S) KD CENTER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 3 WD0421+162 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=358, FLASH=YES, 1 1185 S G FP-POS=3 (1185 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD0421+162 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=341, FLASH=YES, 1 1186 S G FP-POS=4 (1186 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD0421+162 COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=320, FLASH=YES, 1 1390 S G FP-POS=3 (1390 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WD0421+162 COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=310, FLASH=YES, 1 1406 S G FP-POS=4 (1406 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WD0421+162 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=321, FLASH=YES, 1 1397 S G FP-POS=1 (1397 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 WD0421+162 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=321, FLASH=YES, 1 1397 S G FP-POS=2 (1397 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 WD0421+162 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=321, FLASH=YES, 1 1398 S G FP-POS=3 (1398 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 WD0421+162 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=321, FLASH=YES, 1 1398 S G FP-POS=4 (1398 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD0421+162 1 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A KXD WD0421+162 2 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A KD WD0421+162 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G 15068( 4) - 14-Dec-2018 15:19:04 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD0421+162 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G WD0421+162 5 COS/FUV TIME-TA PSA G130M 1222 none none none none 2 N/A G WD0421+162 6 COS/FUV TIME-TA PSA G130M 1222 none none none none 2 N/A G WD0421+162 7 COS/FUV TIME-TA PSA G160M 1577 none none none none 3 N/A G WD0421+162 8 COS/FUV TIME-TA PSA G160M 1577 none none none none 3 N/A G WD0421+162 9 COS/FUV TIME-TA PSA G160M 1577 none none none none 4 N/A G WD0421+162 10 COS/FUV TIME-TA PSA G160M 1577 none none none none 4 N/A G 15068( 4) - 14-Dec-2018 15:19:04 - [ 6] Visit: 04 (WD0437+138 COS) 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 WD0437+138 COS/FUV ACQ/PEA PSA G160M 1577 1 3 S (3 S) KXD ------------------------------------------------------------------------------------------------------------------------------------ 2 WD0437+138 COS/FUV ACQ/PEA PSA G160M 1577 STEP-SIZE=0.9, NUM-POS=5, 1 3 S (3 S) KD CENTER=DEF ------------------------------------------------------------------------------------------------------------------------------------ 3 WD0437+138 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=1000, FLASH=YES, 1 2360 S G FP-POS=1 (2360 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD0437+138 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=1300, FLASH=YES, 1 1410 S G FP-POS=2 (1410 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD0437+138 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=320, FLASH=YES, 1 1408 S G FP-POS=3 (1408 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WD0437+138 COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=1000, FLASH=YES, 1 2923 S G FP-POS=4 (2923 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD0437+138 1 COS/FUV ACQ/PEA PSA G160M 1577 none none none none 1 N/A KXD WD0437+138 2 COS/FUV ACQ/PEA PSA G160M 1577 none none none none 1 N/A KD WD0437+138 3 COS/FUV TIME-TA PSA G160M 1577 none none none none 1 N/A G WD0437+138 4 COS/FUV TIME-TA PSA G160M 1577 none none none none 2 N/A G WD0437+138 5 COS/FUV TIME-TA PSA G160M 1577 none none none none 2 N/A G WD0437+138 6 COS/FUV TIME-TA PSA G160M 1577 none none none none 3 N/A G 15068( 4) - 14-Dec-2018 15:19:04 - [ 7] Visit: 05 (WD0421+162 STIS) 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 WD0421+162 STIS/CCD ACQ F28X50LP MIRROR 1 1 S (1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD0421+162 STIS/NUV TIME-TA 52X0.2 G230M 2800 BUFFER-TIME=500 1 2332 S -MAMA G (2332 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD0421+162 STIS/NUV TIME-TA 52X0.2 G230M 2800 BUFFER-TIME=500 1 2964 S -MAMA G (2964 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD0421+162 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A WD0421+162 2 STIS/NUV TIME-TA 52X0.2 G230M 2800 none none none none 1 N/A -MAMA G WD0421+162 3 STIS/NUV TIME-TA 52X0.2 G230M 2800 none none none none 2 N/A -MAMA G 15068( 4) - 14-Dec-2018 15:19:04 - [ 8] Visit: 06 (WD0437+138 STIS) 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 WD0437+138 STIS/CCD ACQ F28X50LP MIRROR 1 1 S (1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD0437+138 STIS/NUV TIME-TA 52X0.2 G230M 2800 BUFFER-TIME=500 1 2325 S -MAMA G (2325 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD0437+138 STIS/NUV TIME-TA 52X0.2 G230M 2800 BUFFER-TIME=500 1 2957 S -MAMA G (2957 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD0437+138 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A WD0437+138 2 STIS/NUV TIME-TA 52X0.2 G230M 2800 none none none none 1 N/A -MAMA G WD0437+138 3 STIS/NUV TIME-TA 52X0.2 G230M 2800 none none none none 2 N/A -MAMA G 15068( 4) - 14-Dec-2018 15:19:04 - [ 9] Summary Form for Proposal 15068 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, F28X50LP, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, STIS/CCD, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ, ACQ/PEAKD, ACQ/PEAKXD, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1000, BUFFER-TIME=1300, BUFFER-TIME=310, BUFFER-TIME=320, BUFFER-TIME=321, BUFFER-TIME=341, BUFFER-TIME=358, BUFFER-TIME=500, CENTER=DEF, FLASH=YES, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, NUM-POS=5, STEP-SIZE=0.9 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G160M, G230M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names WD0421+162, WD0437+138 ------------------------------------------------------------------------------------------------------------------------------------