0 Assigned ID: 492 ----- Attempting Submission 1 (Fri Apr 08 14:28:54 GMT 2016) ----- Hello, I revised the observation with the new improved dither pattern recommended by my contact scientist Mario Gennaro. With best regards, Bettina Posselt 2088702288 ----- Attempting Submission 1 (Sun Jul 17 18:41:35 GMT 2016) ----- ----- Attempting Submission 2 (Tue Aug 23 18:49:14 GMT 2016) ----- 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. 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). Extrasolar Planets and Planet Formation 12 false false false false false false SUPPORTED STAR NEUTRON STAR PULSAR NO The position is a Chandra position with 2sigma position uncertainty. The proper motion < 80 mas/yr. J2000 J2000 WFC3/IR Imaging No No F160W 1471977131244 The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. /tmp/OPVisit3318454402866553230.xml (Tic-Visit :proposal-id 14745 :visit-id "01" :proposal-version -1 :trans-version "20160601" :date "23-Aug-2016 14:32:11.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1148976 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14745 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14745 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2875 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3307 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14745 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2875 :al-overhead-at-end 0 :internal-dur-at-end 386 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3307 :pcs-gap 0 ) true 2 0