14686( 4) - 02-Nov-2016 13:24:16 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14686 Version: 4 Check-in Time: 02-Nov-2016 13:24:16 STScI Edit Number: 1 Title Confirming Planetary Mass Candidate Companions in Ophiuchus ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Clemence Fontanive Royal Observatory Edinburgh Y CoI: Dr. Katelyn Allers Bucknell University N CoI: Dr. Beth Biller University of Edinburgh, Institute for Y Astronomy CoI: Dr. Mariangela Bonavita Royal Observatory Edinburgh N CoI: Dr. Michael C. Liu University of Hawaii N CoI: Dr. Trent J. Dupuy University of Texas at Austin N ------------------------------------------------------------------------------------ Abstract We propose for follow-up observations to confirm common proper motion for two candidate planetary mass companions, identified as part of our GO 12944 (PI Allers) search for companions to the youngest (~0.5 Myr) brown dwarfs in the nearby Ophiuchus star-forming region. If confirmed to be co-moving, these would be among the lowest mass planetary mass companions imaged to date, with estimated masses <5 Jupiter Masses and would be vital benchmark objects for evolutionary models at these young ages. With our multi-band optical and IR photometric approach based on the SpT-Q relation seen for Ophiuchus brown dwarfs (Allers in prep.), we have already estimated the spectral type of our candidate companions. This approach distinguishes substellar objects from background interlopers based on the strength of the 1.4 um water feature robustly observed in MLTY objects but not in reddened background stars -- both our candidates show clear evidence of absorption at 1.4 um. If confirmed, these candidate companions would significantly increase the census of young planetary mass companions around extremely young brown dwarfs. These candidate companions are too faint to be observed with ground-based laser guide star adaptive optics (LGS AO) nor is the 1.4 um water feature observable from the ground for such faint objects due to telluric absorption, thus HST is the only telescope in the world suitable for these observations. ------------------------------------------------------------------------------------ Observations Description ------------------------ In Cycle 20, we found two low mass candidate companions orbiting a brown dwarf and extremely low mass star respectively in the nearby Ophiuchus star-forming region. Both candidates show evidence of water absorption at 1.4 um, as expected for substellar or planetary mass objects (and would not be seen if they were background stellar contaminants). However, to confirm these objects as true low mass companions, we must measure common proper motion with their primary, requiring a second epoch of observations. 1) The primary goal of the program is to confirm or refute common proper motion for the two candidate companions. If background objects, with ~4 years between observations, we expect ~100 mas of motion relative to their primaries since 14686( 4) - 02-Nov-2016 13:24:16 - [ 2] the first epoch. Thus, followup UVIS F850LP observations with a 40 mas platescale will be critical. 2) the secondary goal is to get a measurement of the depth of water absorption for the candidate around Oph57, which dropped out entirely in this filter in the first epoch observation, but was clearly detected in F127M. Thus, to guarantee that we go deep enough for Oph57, we split the observing time solely between F139M and F850LP. Since the water absorption feature was already well measured in the first epoch GY92-3 observation, we will observe only in F850LP for this target. The first epoch UVIS observations suffered a bit (in terms of cosmic ray removal issues) from only having 2 dither positions per filter (due to avoiding WFC3 full frame serial buffer dumps), so we have primarily used subapertures with either 3 point dithers or box dithers throughout here. Our science is better served by very high quality imaging of the inner 30" than lower quality, less dithered observations of the full chip. The other thing is that the first epoch UVIS images suffered strongly from charge transfer efficiency issues. We've tried to mitigate this in a variety of ways in this observations: 1) For GY92-3, we've chosen the UVIS2_C2K2C_SUB subaperture to place the target as close as possible to the amplifier on the chip. Since we only care about the inner 30", this should be a sufficient field of view. While the UVIS2_C512C_CTE full chip aperture is available too, GY92-3 is bright enough to saturate in less than 349 s, preventing full-frame observations. For the fainter target Oph57 we use the UVIS2_C512C_CTE aperture and the IRSUB512. 2) We've tried to make the exposures reasonably long to increase the background and have also added a postflash of 10 e- for both targets. We've also set ORIENT ranges to avoid the candidate companions accidentally falling into the diffraction spikes. ------------------------------------------------------------------------------------ 14686( 4) - 02-Nov-2016 13:24:16 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CFHTWIR-OPH5 STAR, BROWN DWARF, RA=16H27M4.0230S +/- 0.1", J2000 SpT=M7.25, J=15.06, H=13.92, K=13.18 7 EXTRA-SOLAR PLANET DEC=-24D02'46.90" +/- 0.1" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 2 GY92-3 STAR, BROWN DWARF, RA=16H26M21.8990S +/- 0.1", J2000 SpT=M6.5, I=15.62, J=12.3, H=11.5, EXTRA-SOLAR PLANET DEC=-24D44'39.76" +/- 0.1" K=10.9 Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 14686( 4) - 02-Nov-2016 13:24:16 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 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 ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 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 ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 14686( 4) - 02-Nov-2016 13:24:16 - [ 5] Visit: 01 Visit Requirements: ORIENT 0D TO 70 D; ORIENT 90D TO 160 D; ORIENT 180D TO 250 D; ORIENT 270D TO 340 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CFHTWIR-OPH WFC3/IR MULTIAC IRSUB512 F139M SAMP-SEQ=SPARS25, NSAMP=13 1 DEF GS ACQ SCENARIO SINGLE; 57 CUM (1103.632 PATTERN 3 1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CFHTWIR-OPH WFC3/UVI ACCUM UVIS2-C51 F850LP FLASH=10 1 396 S POS TARG 20, 20; PATTERN 57 S 2C-CTE (1188 S) 4 2 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CFHTWIR-OPH57 1 WFC3/IR MULTIAC IRSUB512 F139M 1 none none none 1 N/A CUM CFHTWIR-OPH57 1 WFC3/IR MULTIAC IRSUB512 F139M 2 none none none 1 N/A CUM CFHTWIR-OPH57 1 WFC3/IR MULTIAC IRSUB512 F139M 3 none none none 1 N/A CUM CFHTWIR-OPH57 1 WFC3/IR MULTIAC IRSUB512 F139M 4 none none none 1 N/A CUM CFHTWIR-OPH57 2 WFC3/UVI ACCUM UVIS2-C5 F850LP 1 none none none 1 N/A S 12C-CTE CFHTWIR-OPH57 2 WFC3/UVI ACCUM UVIS2-C5 F850LP 2 none none none 1 N/A S 12C-CTE CFHTWIR-OPH57 2 WFC3/UVI ACCUM UVIS2-C5 F850LP 3 none none none 1 N/A S 12C-CTE 14686( 4) - 02-Nov-2016 13:24:16 - [ 6] Visit: 02 Visit Requirements: ORIENT 43D TO 113 D; ORIENT 133D TO 203 D; ORIENT 223D TO 293 D; ORIENT 313D TO 23 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GY92-3 WFC3/UVI ACCUM UVIS2-2K2 F850LP FLASH=10 1 254 S (762 PATTERN 4 1 S C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GY92-3 WFC3/UVI ACCUM UVIS2-2K2 F850LP FLASH=10 1 254 S POS TARG 0.28, 0.20; S C-SUB (1016 S) PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ GY92-3 1 WFC3/UVI ACCUM UVIS2-2K F850LP 1 none none none 1 N/A S 2C-SUB GY92-3 1 WFC3/UVI ACCUM UVIS2-2K F850LP 2 none none none 1 N/A S 2C-SUB GY92-3 1 WFC3/UVI ACCUM UVIS2-2K F850LP 3 none none none 1 N/A S 2C-SUB GY92-3 2 WFC3/UVI ACCUM UVIS2-2K F850LP 1 none none none 1 N/A S 2C-SUB GY92-3 2 WFC3/UVI ACCUM UVIS2-2K F850LP 2 none none none 1 N/A S 2C-SUB GY92-3 2 WFC3/UVI ACCUM UVIS2-2K F850LP 3 none none none 1 N/A S 2C-SUB GY92-3 2 WFC3/UVI ACCUM UVIS2-2K F850LP 4 none none none 1 N/A S 2C-SUB 14686( 4) - 02-Nov-2016 13:24:16 - [ 7] Summary Form for Proposal 14686 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IRSUB512, UVIS2-2K2C-SUB, UVIS2-C512C-CTE ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10, NSAMP=13, SAMP-SEQ=SPARS25 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO SINGLE, ORIENT 0D TO 70 D, ORIENT 133D TO 203 D, ORIENT 180D TO 250 D, ORIENT 223D TO 293 D, ORIENT 270D TO 340 D, ORIENT 313D TO 23 D, ORIENT 43D TO 113 D, ORIENT 90D TO 160 D, PATTERN 2 2, PATTERN 3 1, PATTERN 4 1, PATTERN 4 2, POS TARG 0.28, 0.20, POS TARG 20, 20 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F139M, F850LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names CFHTWIR-OPH57, GY92-3 ------------------------------------------------------------------------------------------------------------------------------------