14498( 2) - 23-Mar-2016 20:57:40 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14498 Version: 2 Check-in Time: 23-Mar-2016 20:57:40 STScI Edit Number: 0 Title Comet P/2010 V1 as a Natural Disintegration Laboratory ------------------------------------------------------------------------------------ Type Cycle GO 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. David Jewitt University of California - Los Angeles Y CoI: Dr. Harold A. Weaver The Johns Hopkins University Applied Y Physics Laboratory CoI: Max Mutchler Space Telescope Science Institute Y CoI: Dr. Jessica Agarwal Max Planck Institute for Solar System N Research CoI: Dr. Jing Li University of California - Los Angeles N CoI: Man-To Hui University of California - Los Angeles N CoI: Dr. Karen J. Meech University of Hawaii N CoI: Masateru Ishiguro Seoul National University N CoI: Dr. Jan Kleyna University of Hawaii N CoI: Rob Weryk University of Hawaii N CoI: Dr. Richard Wainscoat University of Hawaii N ------------------------------------------------------------------------------------ Abstract We propose mid-cycle observations of short-period comet P/2010 V1, currently undergoing a spectacular disintegration. Observations already obtained under GO 14474 reveal multiple fragments undergoing rapid evolution, and motivate the additinal high resolution, time-resolved images proposed here. Science objectives are to determine the nature and cause of the breakup by studying the dynamics, and the photometric and morphological evolution of this body. Results will provide key constraints on existing breakup and disintegration models. Our HST data will constitute by far the best observational dataset ever obtained, with unprecedented spatial and temporal resolution. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our basic observing strategy is to take multiple long exposures (348-400 sec) using WFC3 and a wide bandpass filter (F350LP) for maximum sensitivity. We use F350LP because experience in previous HST programs shows that the F350LP count rate is 1.6 times higher for a target with a solar-type spectrum than other commonly used broadband filters (e.g. F606W). We also plan to dither the exposures to mitigate the effects from bad pixels, cosmic rays, and the inter-chip gap. The WFC3 Exposure Time Calculator indicates that, for a point source, solar-type spectrum, a signal-to-noise ratio of 6 is reached in 348 s at V = 26.5 in the F350LP filter (ETC request ID WFC3UVIS.im.765972; optimal extraction yields SNR=13). For example, on UT 2016 March 24, when heliocentric distance R = 1.57 AU, geocentric distance 0.78 AU and phase angle 31 deg, magnitude V = 26.5 corresponds to an object radius 30 m (geometric albedo 0.04 and C-type asteroid phase function assumed). These are upper limits to the point source thresholds because at least some of the fragments are embedded in 14498( 2) - 23-Mar-2016 20:57:40 - [ 2] their own dust comae. However, it is clear that HST offers unprecedented sensitivity to faint fragments. Our observations have the following main objectives, both of which build upon the unprecedented dataset we are acquiring under GO 14474. Five HST orbits, consecutive or as nearly consecutive as possible, will allow us to examine rotationally modulated brightness variations. Five orbits with HST will provide a timebase from which the best possible constraints on the importance of rotation can be obtained. The apparent rates of motion relative to sidereal are easily within Hubble|'s tracking capabilities. The rate of motion is also slow enough to keep a single pair of guide stars within the FGS pickles for an entire visibility window. The ephemeris uncertainties on the main components of P/2010 V1 (e.g. A, B, C, D) are sub-arcsecond. We will position the field so that D and the fragement-rich field in Figure (2) are well-placed but, because of the increasing separation of the components, will have to sacrifice the western-most component A. We understand that we will have essentially no control over the spacecraft roll angle. We request 5 mid-cycle orbits within the April 1-15 window. Under GO 14474 we have schedule HST observations on January 26-28, February 11-13 and March 24. The March 24 observation is timed to coincide with the passage of Earth through the orbital plane of V1, providing a unique and projection-free determination of the out-of-plane velocity of the fragments, Unfortunately, because many fragments are likely aligned very closely with the plane, we expect substantial overlap and confusion with dust on this date and, for many fragments, the best astrometry will come only from the 2-week timebase separating the January and Febuary observations. ------------------------------------------------------------------------------------ 14498( 2) - 23-Mar-2016 20:57:40 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: P2010-V-C-OFFSET ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: COMET test ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=COMET, Q=1.573112870680267E+00, TYPE=POS_ANGLE, RAD=64.8, ANG=289.8, REF=NORTH E=4.905480395391478E-01, I=9.387268291468491E+00, O=3.782156311741634E+00, W=1.524172097988438E+02, T=17-MAR-2016:05:02:50, TTimeScale=TDB, EQUINOX=J2000, EPOCH=12-APR-2016:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 25 +/- 5 Ephemeris Center: EARTH Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 14498( 2) - 23-Mar-2016 20:57:40 - [ 4] Visit: 01 Visit Requirements: BETWEEN 01-APR-2016:00:00:00 AND 14-APR-2016:00:00:00; SEQ 01, 02, 03, 04, 05 WITHIN 1 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 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 3 400 S SEQ 1-2 NON-INT FFSET S ER (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 2 400 S (800 POS TARG 0.2, 2.0 FFSET S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 3 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER 14498( 2) - 23-Mar-2016 20:57:40 - [ 5] Visit: 02 Visit Requirements: BETWEEN 01-APR-2016:00:00:00 AND 14-APR-2016:00:00:00 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 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 3 400 S SEQ 1-2 NON-INT FFSET S ER (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 2 400 S (800 POS TARG 0.2, 2.0 FFSET S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 3 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER 14498( 2) - 23-Mar-2016 20:57:40 - [ 6] Visit: 03 Visit Requirements: BETWEEN 01-APR-2016:00:00:00 AND 14-APR-2016:00:00:00 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 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 3 400 S SEQ 1-2 NON-INT FFSET S ER (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 2 400 S (800 POS TARG 0.2, 2.0 FFSET S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 3 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER 14498( 2) - 23-Mar-2016 20:57:40 - [ 7] Visit: 04 Visit Requirements: BETWEEN 01-APR-2016:00:00:00 AND 14-APR-2016:00:00:00 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 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 3 400 S SEQ 1-2 NON-INT FFSET S ER (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 2 400 S (800 POS TARG 0.2, 2.0 FFSET S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 3 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER 14498( 2) - 23-Mar-2016 20:57:40 - [ 8] Visit: 05 Visit Requirements: BETWEEN 01-APR-2016:00:00:00 AND 14-APR-2016:00:00:00 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 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 3 400 S SEQ 1-2 NON-INT FFSET S ER (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 P2010-V-C-O WFC3/UVI ACCUM UVIS-CENT F350LP CR-SPLIT=NO 2 400 S (800 POS TARG 0.2, 2.0 FFSET S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER P2010-V-C-OFFSET 1 WFC3/UVI ACCUM UVIS-CEN F350LP none none 3 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 1 none 1 N/A S TER P2010-V-C-OFFSET 2 WFC3/UVI ACCUM UVIS-CEN F350LP none none 2 none 1 N/A S TER 14498( 2) - 23-Mar-2016 20:57:40 - [ 9] Summary Form for Proposal 14498 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-APR-2016:00:00:00 AND 14-APR-2016:00:00:00, POS TARG 0.2, 2.0, SEQ 01, 02, 03, 04, 05 WITHIN 1 D, SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F350LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names P2010-V-C-OFFSET ------------------------------------------------------------------------------------------------------------------------------------