11418( 2) - 10/25/07 15:39 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11418 Version: 2 Check-in Time: 25-Oct-2007 19:39:14 STScI Edit Number: 0 Title Investigating the Spectacular Outburst of Comet 17P/Holmes ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO/DD 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Harold A. Weaver The Johns Hopkins University Applied Physics Laboratory CoI: Dr. Carey Lisse The Johns Hopkins University Applied N Physics Laboratory CoI: Dr. Philippe Lamy Laboratoire d'Astronomie Spatiale N CoI: Dr. Imre Toth Hungarian Academy of Sciences N CoI: Dr. William Reach California Institute of Technology N CoI: Dr. Jeremie Vaubaillon California Institute of Technology N CoI: Mr. Max Mutchler Space Telescope Science Institute Y ------------------------------------------------------------------------------------ Abstract Comet 17P/Holmes is currently undergoing a spectacular eruption in activity, with its brightness increasing by ~14 mag over a 24 hour period. The comet is shedding huge amounts of dust, presumably associated with a major splitting event at the nucleus. The high spatial resolution and high sensitivity of Hubble has proven to be invaluable during previous observations of several fragmenting comets, and the 2007 apparition of 17P/Holmes represents another excellent opportunity to investigate this important cometary phenomenon. We request 3 orbits of WFPC2 observations to measure the size and V-R color of the principal nucleus, perform a deep search for large fragments released during the outburst, monitor the temporal development of the event, and search for a satellite whose collision with the principal nucleus may have triggered the current outburst, as was suggested for the similar outburst observed in 1892. ------------------------------------------------------------------------------------ 11418( 2) - 10/25/07 15:39 - [ 2] Observations Description ------------------------ Three identical visits separated by 1-2 days over the next week. Two long exposures in each of two filters, with a small dither shift between them, to mitigate against any bad pixels. One short exposure in each filter, to ensure at least one unsaturated image. The exposures are sequenced to minimize overheads due to filter changes and dither shifts. The long exposures wil be combined to make clean images, and they are separated as much as possible to help with the rejection of star trails. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11418( 2) - 10/25/07 15:39 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: 17P-HOLMES ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: COMET Comet in outburst ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=2.0531685968984,E=0.4324195 | 317478,I=19.11330875529636,O=326.8673862 | 726764,W=24.25862184788592,T = 04-May- | 2007:11:59:44.0,EQUINOX=J2000,EPOCH=01- | May-2007,A1=1.701164E-9,A2=2.844799E-10 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 2.4+/-0.55 | | ------------------------------------------------------------------------------------------------------------------------------------ 11418( 2) - 10/25/07 15:39 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFPC2-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.3535 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 45.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 11418( 2) - 10/25/07 15:39 - [ 5] Visit: 01 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 400 S Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 2 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 400 S Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 3 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 40 S Comments: Short exposure ensure at least one unsaturated image ------------------------------------------------------------------------------------------------------------------------------------ 4 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 40 S POS TARG 0.249, 0.249 Comments: Short exposure ensure at least one unsaturated image ------------------------------------------------------------------------------------------------------------------------------------ 5 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 400 S POS TARG 0.249, 0.249 Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 6 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 400 S POS TARG 0.249, 0.249 Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 17P-HOLMES 1 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 2 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 17P-HOLMES 3 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 17P-HOLMES 4 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 5 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 6 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 11418( 2) - 10/25/07 15:39 - [ 6] Visit: 02 Visit Priority: Visit Requirements: AFTER 01 BY 2 D TO 3 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 400 S Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 2 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 400 S Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 3 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 40 S Comments: Short exposure ensure at least one unsaturated image ------------------------------------------------------------------------------------------------------------------------------------ 4 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 40 S POS TARG 0.249, 0.249 Comments: Short exposure ensure at least one unsaturated image ------------------------------------------------------------------------------------------------------------------------------------ 5 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 400 S POS TARG 0.249, 0.249 Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 6 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 400 S POS TARG 0.249, 0.249 Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 17P-HOLMES 1 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 2 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 17P-HOLMES 3 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 17P-HOLMES 4 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 5 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 6 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 11418( 2) - 10/25/07 15:39 - [ 7] Visit: 03 Visit Priority: Visit Requirements: AFTER 01 BY 5 D TO 6 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 400 S Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 2 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 400 S Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 3 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 40 S Comments: Short exposure ensure at least one unsaturated image ------------------------------------------------------------------------------------------------------------------------------------ 4 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 40 S POS TARG 0.249, 0.249 Comments: Short exposure ensure at least one unsaturated image ------------------------------------------------------------------------------------------------------------------------------------ 5 17P-HOLMES WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 1 400 S POS TARG 0.249, 0.249 Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 6 17P-HOLMES WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 400 S POS TARG 0.249, 0.249 Comments: Long exposure to detect any trailing debris or orbiting satellites ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 17P-HOLMES 1 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 2 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 17P-HOLMES 3 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 17P-HOLMES 4 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 5 WFPC2 IMAGE PC1-FIX F675W none none none none 1 N/A 17P-HOLMES 6 WFPC2 IMAGE PC1-FIX F555W none none none none 1 N/A 11418( 2) - 10/25/07 15:39 - [ 8] Summary Form for Proposal 11418 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0.249, 0.249; AFTER 01 BY 2 D TO 3 D; AFTER 01 BY 5 D TO 6 D; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F675W F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 17P-HOLMES ------------------------------------------------------------------------------------------------------------------------------------