14463( 2) - 11-Dec-2015 19:48:13 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14463 Version: 2 Check-in Time: 11-Dec-2015 19:48:13 STScI Edit Number: 0 Title Identifying the Progenitor of a New Red Transient ------------------------------------------------------------------------------------ Type Cycle GO 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Bruce McCollum Catholic University of America Y CoI: Dr. Frederick C. Bruhweiler Catholic University of America N CoI: Lee Rottler Pisgah Astronomical Research Institute N (PARI) CoI: Dr. Seppo J. Laine California Institute of Technology N ------------------------------------------------------------------------------------ Abstract Red transients are a recently-recognized, fundamentally new type of stellar outburst. At least one, V1309 Sco, was the first observed case of a merger between two nondegenerate stars. The outburst mechanism remains a matter of some disagreement. It is widely suspected that there is more than one different type of outburst occurring among the red transients. A major problem in trying to model the outburst mechanisms is that the spectral class of the progenitor object is fairly well known in only one or two cases. We have found a set of WFC3 images covering the field including one red transient in fifteen different photometric bandpasses. This will provide the most complete SED of any red transient progenitor, and hence the most precise spectroscopic classification. Also, the distance in this case is known to high precision. However, the uncertainty in the coordinates of this transient is such that several objects in the pre-outburst images might be the progenitor. We request a small amount of new WFC3 imaging to determine which object is the progenitor by comparing the location of the transient relative to other stars nearby in the new images. Once it is identified, we will perform photometry on the archival images to construct the SED of the progenitor and derive its spectral type. The combination of precise spectral type and precise distance will make this object fundamentally valuable for modeling red transients. ------------------------------------------------------------------------------------ Observations Description ------------------------ Exposures of same field. Target is a transient detected by Spitzer in July, 2015. This field was imaged in these bandpasses by another program before the transient was discovered. The goal of our program is primarily to locate to within one pixel the precursor star in that crowded field so that archival data can be used to get an SED of it. The secondary goal is to obtain an SED of the transient. No data on this transient have been published except for the Spitzer data, and the transient's SED is not well known based on the nature of the source, so we use multple bandpasses 14463( 2) - 11-Dec-2015 19:48:13 - [ 2] based on a crude extrapolation of the slope from the Spitzer channels. ------------------------------------------------------------------------------------ 14463( 2) - 11-Dec-2015 19:48:13 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 S-15NZ EXT-STAR, M III-I RA=13H37M8.3700S, J2000 V = 20 DEC=-29D50'19.70" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 14463( 2) - 11-Dec-2015 19:48:13 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.572 Line_Spacing 0.365 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 14463( 2) - 11-Dec-2015 19:48:13 - [ 5] Visit: 07 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 S-15NZ WFC3/UVI ACCUM UVIS2-2K2 F814W FLASH=7 1 292 S (584 PATTERN 1 1-3 S C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 S-15NZ WFC3/UVI ACCUM UVIS2-2K2 F625W FLASH=5 1 323 S (646 S C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 S-15NZ WFC3/UVI ACCUM UVIS2-2K2 F606W 1 320 S (640 S C-SUB 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 | ------------------------------------------------------------------------------------------------------------------------------------ S-15NZ 1 WFC3/UVI ACCUM UVIS2-2K F814W 1 none none none 1 N/A S 2C-SUB S-15NZ 1 WFC3/UVI ACCUM UVIS2-2K F814W 2 none none none 1 N/A S 2C-SUB S-15NZ 2 WFC3/UVI ACCUM UVIS2-2K F625W 1 none none none 1 N/A S 2C-SUB S-15NZ 2 WFC3/UVI ACCUM UVIS2-2K F625W 2 none none none 1 N/A S 2C-SUB S-15NZ 3 WFC3/UVI ACCUM UVIS2-2K F606W 1 none none none 1 N/A S 2C-SUB S-15NZ 3 WFC3/UVI ACCUM UVIS2-2K F606W 2 none none none 1 N/A S 2C-SUB 14463( 2) - 11-Dec-2015 19:48:13 - [ 6] Visit: 08 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 S-15NZ WFC3/IR MULTIAC IR F160W NSAMP=8, SAMP-SEQ=STEP100 1 DEF PATTERN 2 1-3 CUM (796.924 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 S-15NZ WFC3/IR MULTIAC IR F125W NSAMP=8, SAMP-SEQ=STEP200 1 DEF CUM (796.924 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 S-15NZ WFC3/IR MULTIAC IR F140W NSAMP=8, SAMP-SEQ=STEP100 1 DEF CUM (796.924 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 | ------------------------------------------------------------------------------------------------------------------------------------ S-15NZ 1 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM S-15NZ 1 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM S-15NZ 1 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM S-15NZ 1 WFC3/IR MULTIAC IR F160W 4 none none none 1 N/A CUM S-15NZ 2 WFC3/IR MULTIAC IR F125W 1 none none none 1 N/A CUM S-15NZ 2 WFC3/IR MULTIAC IR F125W 2 none none none 1 N/A CUM S-15NZ 2 WFC3/IR MULTIAC IR F125W 3 none none none 1 N/A CUM S-15NZ 2 WFC3/IR MULTIAC IR F125W 4 none none none 1 N/A CUM S-15NZ 3 WFC3/IR MULTIAC IR F140W 1 none none none 1 N/A CUM S-15NZ 3 WFC3/IR MULTIAC IR F140W 2 none none none 1 N/A CUM S-15NZ 3 WFC3/IR MULTIAC IR F140W 3 none none none 1 N/A CUM S-15NZ 3 WFC3/IR MULTIAC IR F140W 4 none none none 1 N/A CUM 14463( 2) - 11-Dec-2015 19:48:13 - [ 7] Summary Form for Proposal 14463 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS2-2K2C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=5, FLASH=7, NSAMP=8, SAMP-SEQ=STEP100, SAMP-SEQ=STEP200 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1-3, PATTERN 2 1-3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F125W, F140W, F160W, F606W, F625W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names S-15NZ ------------------------------------------------------------------------------------------------------------------------------------