12117( 3) - 12-May-2010 18:37:30 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12117 Version: 3 Check-in Time: 12-May-2010 18:37:30 STScI Edit Number: 1 Title Determining the Nature of an Exceptional Optical Transient ------------------------------------------------------------------------------------ Type Cycle GO/DD 17 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Andrew Drake California Institute of Technology CoI: Prof. S. George Djorgovski California Institute of Technology N CoI: Dr. Ashish Mahabal California Institute of Technology N CoI: Dr. Jay Anderson Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract During the course of the Catalina Real-time Transient Survey (CRTS) we have discovered an exceptionally luminous optical transient. The source of this event appears to be either the most luminous supernova ever discovered, or the first clear optical detection of the tidal disruption of a star by a massive black hole. In spite of numerous ground and space-based observations the exact nature of the event remains unclear. High spatial resolution observations with HST WFC3 are critical to solving this mystery. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will use HST WFC3-UVIS channel subarray observations with F390W, F555W & F763M to image the target seven times with each filter during one orbit. Using HST WFC3 exposure calculator, along with our May 5th opitcal spectrum as input, we find that S/N > 200 observations can be achieved with F390W, F555W & F763M in 45, 35, and 75 seconds, respectively. Our observations will consist of seven exposures in each filter in a custom bulit pattern designed specifically to reconstruct the image with the best possible resolution will also mitigate the impact of hot pixels and cosmic rays. These images will be taken using F390W, F555W, and F763M. F390W will highlight the location of the hot blue host-AGN component. F555W will trace the continuum component and observations with F763M will highlight the location of the strongest (red-shifted) H_alpha emission (which lies at the center of this filter's transmission), without also including the significant continuum component of a broader filter. We will use 1kx1k pixel subarrays which will allow us to stack the images thus greatly decrease the readout overheads with the buffer dump occuring after occultation but with the orbit. This array size gives us a 40" field of view which contains the entire galaxy target plus a nearby star. The visit planner suggests such observation can be sheduled throughout May and Jun. May dates are perfered since the target is a fading transient source. 12117( 3) - 12-May-2010 18:37:30 - [ 2] Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12117( 3) - 12-May-2010 18:37:30 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CSS100217 GALAXY, SEYFERT, RA=10H29M12.5800S +/- 0.1", J2000 Z = V = 16.5 +/- 0.5 STARBURST DEC=+40D42'19.70" +/- 0.1" 0.147 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 12117( 3) - 12-May-2010 18:37:30 - [ 4] Visit: 01 Visit Requirements: PCS MODE FINE; BEFORE 10-JUL-2010:00:00:00 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 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F390W CR-SPLIT=NO 1 45 S POS TARG 0.000, 0.000; S 1C-SUB GS ACQ SCENARIO BASE1B3 ------------------------------------------------------------------------------------------------------------------------------------ 2 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F390W CR-SPLIT=NO 1 45 S POS TARG 0.248470, S 1C-SUB 0.140904 ------------------------------------------------------------------------------------------------------------------------------------ 3 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F390W CR-SPLIT=NO 1 45 S POS TARG 0.496949, S 1C-SUB 0.281800 ------------------------------------------------------------------------------------------------------------------------------------ 4 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F390W CR-SPLIT=NO 1 45 S POS TARG 0.739786, S 1C-SUB 0.422335 ------------------------------------------------------------------------------------------------------------------------------------ 5 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F390W CR-SPLIT=NO 1 45 S POS TARG 0.124292, S 1C-SUB 0.506064 ------------------------------------------------------------------------------------------------------------------------------------ 6 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F390W CR-SPLIT=NO 1 45 S POS TARG 0.372756, S 1C-SUB 0.646968 ------------------------------------------------------------------------------------------------------------------------------------ 7 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F390W CR-SPLIT=NO 1 45 S POS TARG 0.621229, S 1C-SUB 0.787864 ------------------------------------------------------------------------------------------------------------------------------------ 8 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F555W CR-SPLIT=NO 1 35 S SAME POS AS 1 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 9 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F555W CR-SPLIT=NO 1 35 S SAME POS AS 2 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 10 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F555W CR-SPLIT=NO 1 35 S SAME POS AS 3 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 11 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F555W CR-SPLIT=NO 1 35 S SAME POS AS 4 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 12 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F555W CR-SPLIT=NO 1 35 S SAME POS AS 5 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 13 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F555W CR-SPLIT=NO 1 35 S SAME POS AS 6 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 14 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F555W CR-SPLIT=NO 1 35 S SAME POS AS 7 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 12117( 3) - 12-May-2010 18:37:30 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F763M CR-SPLIT=NO 1 75 S SAME POS AS 1 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 16 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F763M CR-SPLIT=NO 1 75 S SAME POS AS 2 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 17 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F763M CR-SPLIT=NO 1 75 S SAME POS AS 3 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 18 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F763M CR-SPLIT=NO 1 75 S SAME POS AS 4 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 19 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F763M CR-SPLIT=NO 1 75 S SAME POS AS 5 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 20 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F763M CR-SPLIT=NO 1 75 S SAME POS AS 6 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 21 CSS100217 WFC3/UVI ACCUM UVIS2-M1K F763M CR-SPLIT=NO 1 75 S SAME POS AS 7 S 1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CSS100217 1 WFC3/UVI ACCUM UVIS2-M1 F390W none none none none 1 N/A S K1C-SUB CSS100217 2 WFC3/UVI ACCUM UVIS2-M1 F390W none none none none 1 N/A S K1C-SUB CSS100217 3 WFC3/UVI ACCUM UVIS2-M1 F390W none none none none 1 N/A S K1C-SUB CSS100217 4 WFC3/UVI ACCUM UVIS2-M1 F390W none none none none 1 N/A S K1C-SUB CSS100217 5 WFC3/UVI ACCUM UVIS2-M1 F390W none none none none 1 N/A S K1C-SUB CSS100217 6 WFC3/UVI ACCUM UVIS2-M1 F390W none none none none 1 N/A S K1C-SUB CSS100217 7 WFC3/UVI ACCUM UVIS2-M1 F390W none none none none 1 N/A S K1C-SUB CSS100217 8 WFC3/UVI ACCUM UVIS2-M1 F555W none none none none 1 N/A S K1C-SUB CSS100217 9 WFC3/UVI ACCUM UVIS2-M1 F555W none none none none 1 N/A S K1C-SUB CSS100217 10 WFC3/UVI ACCUM UVIS2-M1 F555W none none none none 1 N/A S K1C-SUB 12117( 3) - 12-May-2010 18:37:30 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ CSS100217 11 WFC3/UVI ACCUM UVIS2-M1 F555W none none none none 1 N/A S K1C-SUB CSS100217 12 WFC3/UVI ACCUM UVIS2-M1 F555W none none none none 1 N/A S K1C-SUB CSS100217 13 WFC3/UVI ACCUM UVIS2-M1 F555W none none none none 1 N/A S K1C-SUB CSS100217 14 WFC3/UVI ACCUM UVIS2-M1 F555W none none none none 1 N/A S K1C-SUB CSS100217 15 WFC3/UVI ACCUM UVIS2-M1 F763M none none none none 1 N/A S K1C-SUB CSS100217 16 WFC3/UVI ACCUM UVIS2-M1 F763M none none none none 1 N/A S K1C-SUB CSS100217 17 WFC3/UVI ACCUM UVIS2-M1 F763M none none none none 1 N/A S K1C-SUB CSS100217 18 WFC3/UVI ACCUM UVIS2-M1 F763M none none none none 1 N/A S K1C-SUB CSS100217 19 WFC3/UVI ACCUM UVIS2-M1 F763M none none none none 1 N/A S K1C-SUB CSS100217 20 WFC3/UVI ACCUM UVIS2-M1 F763M none none none none 1 N/A S K1C-SUB CSS100217 21 WFC3/UVI ACCUM UVIS2-M1 F763M none none none none 1 N/A S K1C-SUB 12117( 3) - 12-May-2010 18:37:30 - [ 7] Summary Form for Proposal 12117 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-M1K1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 10-JUL-2010:00:00:00, GS ACQ SCENARIO BASE1B3, PCS MODE FINE, POS TARG 0.000, 0.000, POS TARG 0.124292, 0.506064, POS TARG 0.248470, 0.140904, POS TARG 0.372756, 0.646968, POS TARG 0.496949, 0.281800, POS TARG 0.621229, 0.787864, POS TARG 0.739786, 0.422335, SAME POS AS 1, SAME POS AS 2, SAME POS AS 3, SAME POS AS 4, SAME POS AS 5, SAME POS AS 6, SAME POS AS 7 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F390W, F555W, F763M ------------------------------------------------------------------------------------------------------------------------------------ Target Names CSS100217 ------------------------------------------------------------------------------------------------------------------------------------