14646( 4) - 19-Jan-2017 10:42:51 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14646 Version: 4 Check-in Time: 19-Jan-2017 10:42:51 STScI Edit Number: 0 Title A White Dwarf with an Actively Disintegrating Asteroid ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Siyi Xu European Southern Observatory - Germany Y CoI: Mr. Andrew Vanderburg Harvard University N CoI: Dr. John Henry Debes Space Telescope Science Institute N CoI: Dr. Patrick Dufour Universite de Montreal N CoI: Dr. Philip Steven Muirhead Boston University N CoI: Dr. Bryce J Croll Boston University N CoI: Prof. Ben M. Zuckerman University of California - Los Angeles N CoI: Justin Ely Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract We have recently discovered a white dwarf with an actively disintegrating asteroid. Using data from the Kepler extended mission, transits with periods less than 5 hours have been detected from at least 6 objects. Evidence for circumstellar dust was found by comparing UKIDSS and WISE data. High-resolution optical spectroscopic data from Keck show that the host star is heavily polluted with 11 heavy elements and also displays numerous absorption lines from circumstellar gas. This system has become much more active since its original discovery. We were granted mid-cycle observing time with Hubble and a few other telescopes to perform simultaneous observations. Our preliminary analysis already shows new emerging features. We propose to monitor this system two more times for the next year and study the real time disintegration of an asteroid around a white dwarf. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our goal is threefold: (i) use TIME-TAG data to monitor the potential changes of circumstellar lines; (ii) measure a transit light curve in the ultraviolet; (iii) to detect additional trace elements. To cover all the lines of interest, we will employ the G130M grating with a central wavelength of 1291 Angstrom and a wavelength coverage of 1137-1274 Angstrom and 1292-1432 Angstrom. We used the COS spectra as an input template and with ETC v24.1, we find that an average S/N of 20 can be reached in most regions for a total exposure time of 17000 sec (6 orbits). For target acquisition, we will only employ ACQ/IMG because the position of our target is well known. Including overheads, a total of 6 orbits is required for each set of observation. In order to cover the full 4.5 period, we separate the 6 orbits into two set of observations, 3 orbits each and separtaed by 10 orbits in between. We will repeat this set of observations and a total of 12 orbits are required. We prefer the two set of observations to be scheduled at least 30 days apart to understand the long term evolution of the system. We will also combine all the 14646( 4) - 19-Jan-2017 10:42:51 - [ 2] data together to produce a high quality ultraviolet spectrum of the target. The total S/N (including our mid-cycle data) would be over 30 and we will be able to detect or put good upper limit on a set of trace elements. We prefer the observation to be scheduled during the time that simultaneous ground-based observation is possible. ------------------------------------------------------------------------------------ 14646( 4) - 19-Jan-2017 10:42:51 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 WD-1145+017 STAR, DB RA=11H48M33.6270S +/- 0.04", J2000 V = 17.3 DEC=+01D28'59.45" +/- 0.043" Reference Frame: ICRS Extended: NO Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.002887634121500669 -0.007 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 14646( 4) - 19-Jan-2017 10:42:51 - [ 4] Visit: 01 (WD1145_obs1) Visit Requirements: SCHED 40% 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 WD-1145+017 COS/NUV ACQ/IMA PSA MIRRORB 1 45 S (45 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=1, SEGMENT=BOTH see below (1938 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 325 S G FP-POS=2, SEGMENT=BOTH see below (291 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1647 S G FP-POS=2, SEGMENT=BOTH see below (1620 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1124 S G FP-POS=3, SEGMENT=BOTH see below (1097 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 848 S G FP-POS=3, SEGMENT=BOTH see below (787 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=4, SEGMENT=BOTH see below (1911 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE WD-1145+017 2 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 1938.0 S G WD-1145+017 3 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 291.0 S G WD-1145+017 4 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 1620.0 S G 14646( 4) - 19-Jan-2017 10:42:51 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 5 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 1097.0 S G WD-1145+017 6 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 787.0 S G WD-1145+017 7 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 1911.0 S G 14646( 4) - 19-Jan-2017 10:42:51 - [ 6] Visit: 02 (WD1145_obs2) Visit Requirements: SCHED 40%; AFTER 01 BY 9.8 Orbits TO 10.2 Orbits 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 WD-1145+017 COS/NUV ACQ/IMA PSA MIRRORB 1 45 S (45 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=1, SEGMENT=BOTH see below (1938 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 325 S G FP-POS=2, SEGMENT=BOTH see below (291 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1647 S G FP-POS=2, SEGMENT=BOTH see below (1620 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1124 S G FP-POS=3, SEGMENT=BOTH see below (1097 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 848 S G FP-POS=3, SEGMENT=BOTH see below (787 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=4, SEGMENT=BOTH see below (1911 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE WD-1145+017 2 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 1938.0 S G WD-1145+017 3 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 291.0 S G WD-1145+017 4 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 1620.0 S G 14646( 4) - 19-Jan-2017 10:42:51 - [ 7] 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 5 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 1097.0 S G WD-1145+017 6 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 787.0 S G WD-1145+017 7 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 1911.0 S G 14646( 4) - 19-Jan-2017 10:42:51 - [ 8] Visit: 03 (WD1145_obs3) Visit Requirements: AFTER 02 BY 30 D TO 180 D 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 WD-1145+017 COS/NUV ACQ/IMA PSA MIRRORB 1 45 S (45 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=1, SEGMENT=BOTH see below (1965 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 325 S G FP-POS=2, SEGMENT=BOTH see below (318 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1647 S G FP-POS=2, SEGMENT=BOTH (1647 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1124 S G FP-POS=3, SEGMENT=BOTH (1124 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 848 S G FP-POS=3, SEGMENT=BOTH see below (814 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=4, SEGMENT=BOTH see below (1938 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE WD-1145+017 2 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 1965.0 S G WD-1145+017 3 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 318.0 S G WD-1145+017 4 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 N/A G WD-1145+017 5 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 N/A G 14646( 4) - 19-Jan-2017 10:42:51 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 6 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 814.0 S G WD-1145+017 7 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 1938.0 S G 14646( 4) - 19-Jan-2017 10:42:51 - [ 10] Visit: 04 (WD1145_obs4) Visit Requirements: AFTER 03 BY 9.8 Orbits TO 10.2 Orbits 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 WD-1145+017 COS/NUV ACQ/IMA PSA MIRRORB 1 45 S (45 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=1, SEGMENT=BOTH see below (1965 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 325 S G FP-POS=2, SEGMENT=BOTH see below (318 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1647 S G FP-POS=2, SEGMENT=BOTH (1647 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1124 S G FP-POS=3, SEGMENT=BOTH (1124 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 848 S G FP-POS=3, SEGMENT=BOTH see below (814 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WD-1145+017 COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=1000, FLASH=YES, 1 1972 S G FP-POS=4, SEGMENT=BOTH see below (1938 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE WD-1145+017 2 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 1965.0 S G WD-1145+017 3 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 318.0 S G WD-1145+017 4 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 N/A G WD-1145+017 5 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 N/A G 14646( 4) - 19-Jan-2017 10:42:51 - [ 11] 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 | ------------------------------------------------------------------------------------------------------------------------------------ WD-1145+017 6 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 814.0 S G WD-1145+017 7 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 1938.0 S G 14646( 4) - 19-Jan-2017 10:42:51 - [ 12] Summary Form for Proposal 14646 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1000, FLASH=YES, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 9.8 Orbits TO 10.2 Orbits, AFTER 02 BY 30 D TO 180 D, AFTER 03 BY 9.8 Orbits TO 10.2 Orbits, SCHED 40% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names WD-1145+017 ------------------------------------------------------------------------------------------------------------------------------------