13511( 2) - 27-Sep-2013 15:51:47 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13511 Version: 2 Check-in Time: 27-Sep-2013 15:51:47 STScI Edit Number: 0 Title CXOU J122518.6+144545: Type IIn supernova or hyperluminous X-ray source? ------------------------------------------------------------------------------------ Type Cycle GO 21 ------------------------------------------------------------------------------------ Investigators Contact? PI: Ms. Marianne Heida Space Research Organization Netherlands Y CoI: Dr. Peter Gustaaf Jonker Space Research Organization Netherlands N CoI: Dr. Manuel Torres Space Research Organization Netherlands N ------------------------------------------------------------------------------------ Abstract In 2010 we reported the discovery of CXOU J122518.6+144545. A new Chandra observation in 2012 showed that it varies by more than a factor 10 in X-ray flux. This leaves us with two options: we either discovered a rare type IIn SN, or the second most luminous HLX thus far. Deeper Chandra observations combined with a new HST visit will decide between these scenarios. If CXO J1225 was a supernova, with these new data we will be able to identify the progenitor star. This will be only the second type IIn SN for which this is done. If instead the source is an HLX it is a strong candidate to contain an intermediate mass black hole. In this case the new Chandra data will give us information about its variability and the HST image will give us stronger constraints on the size of the optical source. ------------------------------------------------------------------------------------ Observations Description ------------------------ We plan to take a deep image to observe the counterpart of the X-ray source CXO J122518.6+144545 using WFC3/UVIS. We use the F475W filter for consistency with a previous HST/ACS observation. We use the standard WFC3/UVIS box dither pattern with four dither points to remove cosmic rays and bad pixels and to optimally sample the PSF. In one orbit we can fit four 628 s exposures and overheads, which gives us a total exposure time of 2512 seconds. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 13511( 2) - 27-Sep-2013 15:51:47 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CXOU-J122518 EXT-STAR, ACCRETION RA=12H25M18.6500S, J2000 g' = 26.4+/-0.1, g'-z' < 0.7, values .6+144545 DISK, SUPERNOVA TYPE DEC=+14D45'45.76" from ACS obs in 2003, source can be II, X-RAY TRANSIENT fainter if it is a fading SN Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 13511( 2) - 27-Sep-2013 15:51:47 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13511( 2) - 27-Sep-2013 15:51:47 - [ 4] Visit: 01 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CXOU-J12251 WFC3/UVI ACCUM UVIS F475W 1 600 S PATTERN 1 1 8.6+144545 S see below (2512 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 | ------------------------------------------------------------------------------------------------------------------------------------ CXOU-J122518.6+1445 1 WFC3/UVI ACCUM UVIS F475W 1 none none none 1 628.0 S 45 S CXOU-J122518.6+1445 1 WFC3/UVI ACCUM UVIS F475W 2 none none none 1 628.0 S 45 S CXOU-J122518.6+1445 1 WFC3/UVI ACCUM UVIS F475W 3 none none none 1 628.0 S 45 S CXOU-J122518.6+1445 1 WFC3/UVI ACCUM UVIS F475W 4 none none none 1 628.0 S 45 S 13511( 2) - 27-Sep-2013 15:51:47 - [ 5] Summary Form for Proposal 13511 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F475W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CXOU-J122518.6+144545 ------------------------------------------------------------------------------------------------------------------------------------