10204( 3) - 05/12/04 10:49 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10204 Version: 3 Check-in Date: 12-May-2004 14:46:36 1.Proposal Title: Evolution of Light Echoes of SN 1993J ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Ben E.K. Sugerman Space Telescope Science Institute CoI: Dr. Arlin Crotts Columbia University in the City of New N York ------------------------------------------------------------------------------------ 6. Abstract SN 1993J is the nearest SN in the last decade, and only one of seven objects to produce confirmed light echoes. Our analyses of archival HST/WFPC2 datareve aled that the SN has illuminated at least two light-echo structures in the galaxy M81. Those echoes appear to define two sheets of dust, located roughly 260 ly and 770 ly in front of the SN, which are the first, and most efficient, 3-D probes of the ISM in M81. The echoes not only reveal the ISM's structure, but also constrain the density, composition and grain-size of its dust. Echoes are transient events, and as they change on timescales shorter than a year, continued monitoring will reveal new illuminated material, tracing interstellar and circumstellar structure. We propose a modest and highly efficient campaign by HST to image these and yet undiscovered echoes toward SN 1993J. Such observations will build the first direct 3-D map of the ISM within a million cubic parsecs of M81's spiral arm, and may glimpse the circumstellar environment affected by the projenitor's mass loss. Such results probe the nature of extragalactic dust, reveal spatio-kinematic information about the M81's disk, tightly constrain its internal extinction, and under the proper circumstances, provide an independent distance measurement to the host galaxy. ------------------------------------------------------------------------------------ 10204( 3) - 05/12/04 10:49 - [ 2] Observations Description ------------------------ 5 orbits split into three visits. Visit 1: 1 orbit WFPC2 F555W and F675W to be taken any time in cycle 13, but preferably in the middle, i.e. 3 months after visit 2 and 3 months before visit 3. Visit 2: 3 orbits ACS/HRC in F330W, F535W, F555W, F625W, F814W taken during the first 3 months of the cycle. Visit 3: 1 orbit ACS/HRC F625W and F814W taken 6 months after the first ACS visit. Exposure times have been chosen based on the echo brightness in May 2001 as shown on archival ACS/HRC images and using the dust-scattering model of Sugerman (2003). Light echoes change on timescales equal to the duration of the supernova outburst that created them. At least 6 months are needed between the first and second epochs of ACS/HRC observations to detect motion of the echoes. With the first ACS visit made in the first 3 months of cycle 13, and the second made toward the end (more than 6 months later), the observed echoes will probe new material at each visit. An observation with WFPC2 in between these dates will provide better temporal coverage, but its timing is not strongly constrained. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10204( 3) - 05/12/04 10:49 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN1993J EXT-STAR, SUPERNOVA RA=09H55M24.77S +/- 0.1", J2000 V = 20.6 DEC=+69D01'13.7" +/- 0.1" Coordinate Source: Other_Source: ICRS coordinates 10204( 3) - 05/12/04 10:49 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFPC2-LINE Pattern_Purpose BACKGROUND Number_Of_Points 2 Point_Spacing 0.22775 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 45.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type ACS-HRC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.198 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 44.28 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 10204( 3) - 05/12/04 10:49 - [ 5] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: This visit can be scheduled at any time in cycle 13. If scheduling permits, it would be nice if the visit could be made either (a) very close in time with visit 2, or (b) roughly 3 months after visit 2. In order of priority, please choose: (a) first, then (b), or any time in the cycle. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN1993J WFPC2 IMAGE PC1 F675W CR-SPLIT=NO,CR-TOLERANCE=0., 1 600 S PATTERN 1 1-2 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 2 SN1993J WFPC2 IMAGE PC1 F555W CR-SPLIT=NO,CR-TOLERANCE=0., 1 500 S CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 1 none none none 1 600.0 01 1 2 none none none 1 600.0 01 2 1 none none none 1 500.0 01 2 2 none none none 1 600.0 10204( 3) - 05/12/04 10:49 - [ 6] Visit: 02 Visit Priority: Visit Requirements: PCS MODE FINE; BETWEEN 01-JUN-2004:00:00:00 AND 01-OCT-2004:00:00:00 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN1993J ACS/HRC ACCUM HRC F330W CR-SPLIT=2,PAREXP=NONE 1 800 S POS TARG 1.5,-1; PATTERN 2 1-5 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN1993J ACS/HRC ACCUM HRC F555W CR-SPLIT=NO,PAREXP=NONE 1 400 S POS TARG 1.5,-1 ------------------------------------------------------------------------------------------------------------------------------------ 3 SN1993J ACS/HRC ACCUM HRC F625W CR-SPLIT=NO,PAREXP=NONE 1 400 S POS TARG 1.5,-1 ------------------------------------------------------------------------------------------------------------------------------------ 4 SN1993J ACS/HRC ACCUM HRC F435W CR-SPLIT=NO,PAREXP=NONE 1 516 S POS TARG 1.5,-1 ------------------------------------------------------------------------------------------------------------------------------------ 5 SN1993J ACS/HRC ACCUM HRC F814W CR-SPLIT=NO,PAREXP=NONE 1 618 S POS TARG 1.5,-1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 1 1 none none 1 1 tbd 02 1 1 none none 2 1 tbd 02 1 2 none none 1 2 tbd 02 1 2 none none 2 2 tbd 02 1 3 none none 1 3 tbd 02 1 3 none none 2 3 tbd 02 2 1 none none none 1 tbd 02 2 2 none none none 2 tbd 02 2 3 none none none 3 tbd 02 3 1 none none none 1 tbd 02 3 2 none none none 2 tbd 02 3 3 none none none 3 tbd 02 4 1 none none none 1 tbd 02 4 2 none none none 2 tbd 02 4 3 none none none 3 tbd 02 5 1 none none none 1 503.0 02 5 2 none none none 2 tbd 02 5 3 none none none 3 tbd 10204( 3) - 05/12/04 10:49 - [ 7] Visit: 03 Visit Priority: Visit Requirements: PCS MODE FINE; AFTER 02 BY 180 D TO 270 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 SN1993J ACS/HRC ACCUM HRC F625W CR-SPLIT=NO,PAREXP=NONE 1 400 S POS TARG 1.5,-1; PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN1993J ACS/HRC ACCUM HRC F814W CR-SPLIT=NO,PAREXP=NONE 1 468 S POS TARG 1.5,-1; PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 03 1 1 none none none 1 tbd 03 1 2 none none none 1 tbd 03 1 3 none none none 1 tbd 03 2 1 none none none 1 tbd 03 2 2 none none none 1 tbd 03 2 3 none none none 1 tbd 10204( 3) - 05/12/04 10:49 - [ 8] Summary Form for Proposal 10204 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1 HRC ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO CR-TOLERANCE=0. CLOCKS=YES PAREXP=NONE ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE PATTERN 1 1-2 PCS MODE FINE; BETWEEN 01-JUN-2004 00 00 00 AND 01-OCT-2004 00 00 00 POS TARG 1.5,-1; PATTERN 2 1-5 POS TARG 1.5,-1 PCS MODE FINE; AFTER 02 BY 180 D TO 270 D POS TARG 1.5,-1; PATTERN 2 1 POS TARG 1.5,-1; PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F675W F555W F330W F625W F435W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN1993J ------------------------------------------------------------------------------------------------------------------------------------