14745( 4) - 24-Aug-2016 19:47:14 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14745 Version: 4 Check-in Time: 24-Aug-2016 19:47:14 STScI Edit Number: 0 Title Is there a substellar companion around the neutron star RX J0806.4-4123? ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Bettina Posselt The Pennsylvania State University Y CoI: Dr. George G. Pavlov The Pennsylvania State University N CoI: Prof. Kevin Luhman The Pennsylvania State University N ------------------------------------------------------------------------------------ Abstract Deep near-infrared (NIR) observations from the ground, first with the VLT in the H-band and recently with Gemini in the J-band, showed indication of a faint (~24-25 mag) flux enhancement at the position of the young (~0.5 Myr) nearby (250 pc) isolated neutron star RX J0806.4-4123. The combined detection significance of these two independent NIR observations is 3.1sigma. Previous Hubble observations in the optical showed that there are no other objects within 2.5 arcsec, and established that the neutron star itself is very faint (STmag of 28 in the F475W filter). The neutron star is expected to be even fainter in the NIR, because young neutron stars have their emission maximum in the UV to X-ray range. Hence, emission from the neutron star surface cannot be responsible for the NIR flux enhancement at the position of RX J0806.4-4123. The NIR emission could come from a young warm substellar companion which has about 13 Jupiter masses. We propose deep H-band observations of RX J0806.4-4123 in order to (i) confirm unambiguously the very faint NIR emission, (2) detect it with the required astrometric precision to enable the confirmation of the putative companion by studying its co-motion, (3) prepare follow-up JWST investigations. ------------------------------------------------------------------------------------ Observations Description ------------------------ This programs aims to confirm a faint H~25 mag source with WFC3/IR, measure its H magnitude, and get as a good astrometric position as possible. The source is very likely a point source, but we cannot entirely exclude an extended object. We use WFC3/IR with the F160W and observe the target in 1 visit with 2 orbits. We use 6 dither positions in total, and employ 3x SPARS100, NSAMP=10 (902s) in each orbit. Since there are relatively bright (H~12 mag) stars at >10 arcsec, we employ only a small dither offsets. In particular we use an improved 6-point dither strategy recently developed by the instrument team (Jay Anderson et al.) in order to achieve better photometry and astrometry accuracies. We also use an ORIENT constraint to avoid the diffraction spikes of one nearby (12 arcsec) bright star (PA=313.5, East of North). ------------------------------------------------------------------------------------ 14745( 4) - 24-Aug-2016 19:47:14 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 RX-J0806.4-4 STAR, NEUTRON STAR, RA=08H06M23.4000S +/- 0.6", J2000 V = 28 123 PULSAR DEC=-41D22'30.90" +/- 0.6" Reference Frame: Other: SIMBAD Extended: NO Comments: The position is a Chandra position with 2sigma position uncertainty. The proper motion < 80 mas/yr. ------------------------------------------------------------------------------------------------------------------------------------ 14745( 4) - 24-Aug-2016 19:47:14 - [ 3] Visit: 01 Visit Requirements: ORIENT 0D TO 33.5 D; ORIENT 53.5D TO 123.5 D; ORIENT 143.5D TO 213.5 D; ORIENT 233.5D TO 303.5 D; ORIENT 323.5D TO 359 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 RX-J0806.4- WFC3/IR MULTIAC IR F160W NSAMP=10, SAMP-SEQ=SPARS100 1 DEF POS TARG 0, 0 4123 CUM (902.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 RX-J0806.4- WFC3/IR MULTIAC IR F160W NSAMP=10, SAMP-SEQ=SPARS100 1 DEF POS TARG 0.7, 0.063 4123 CUM (902.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 RX-J0806.4- WFC3/IR MULTIAC IR F160W NSAMP=10, SAMP-SEQ=SPARS100 1 DEF POS TARG 1.399, 0.025 4123 CUM (902.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 RX-J0806.4- WFC3/IR MULTIAC IR F160W NSAMP=10, SAMP-SEQ=SPARS100 1 DEF POS TARG 0.068, 0.706 4123 CUM (902.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 RX-J0806.4- WFC3/IR MULTIAC IR F160W NSAMP=10, SAMP-SEQ=SPARS100 1 DEF POS TARG 0.768, 0.648 4123 CUM (902.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 RX-J0806.4- WFC3/IR MULTIAC IR F160W NSAMP=10, SAMP-SEQ=SPARS100 1 DEF POS TARG 1.468, 0.690 4123 CUM (902.935 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 | ------------------------------------------------------------------------------------------------------------------------------------ RX-J0806.4-4123 1 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM RX-J0806.4-4123 2 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM RX-J0806.4-4123 3 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM RX-J0806.4-4123 4 WFC3/IR MULTIAC IR F160W none none none none 2 N/A CUM RX-J0806.4-4123 5 WFC3/IR MULTIAC IR F160W none none none none 2 N/A CUM 14745( 4) - 24-Aug-2016 19:47:14 - [ 4] 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 | ------------------------------------------------------------------------------------------------------------------------------------ RX-J0806.4-4123 6 WFC3/IR MULTIAC IR F160W none none none none 2 N/A CUM 14745( 4) - 24-Aug-2016 19:47:14 - [ 5] Summary Form for Proposal 14745 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=10, SAMP-SEQ=SPARS100 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 0D TO 33.5 D, ORIENT 143.5D TO 213.5 D, ORIENT 233.5D TO 303.5 D, ORIENT 323.5D TO 359 D, ORIENT 53.5D TO 123.5 D, POS TARG 0, 0, POS TARG 0.068, 0.706, POS TARG 0.7, 0.063, POS TARG 0.768, 0.648, POS TARG 1.399, 0.025, POS TARG 1.468, 0.690 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names RX-J0806.4-4123 ------------------------------------------------------------------------------------------------------------------------------------