0 Assigned ID: 198 ----- Attempting Submission 1 (Thu Apr 09 14:40:22 GMT 2015) ----- HST Phase I Proposal 198 (fwtau_cyc23.apt) successfully submitted. Receipt: # 198-1 ----- Attempting Submission 2 (Thu Apr 09 19:33:09 GMT 2015) ----- Updated CR-SPLIT 1927009793 ----- Attempting Submission 1 (Sat Jul 18 16:54:31 GMT 2015) ----- ----- Attempting Submission 2 (Sat Aug 01 06:24:45 GMT 2015) ----- ----- Attempting Submission 3 (Wed Oct 07 02:20:45 GMT 2015) ----- Your proposal could not be saved. Submission aborted. ----- Attempting Submission 4 (Wed May 25 12:03:08 GMT 2016) ----- Planetary mass companions to solar mass stars may form through core accretion, gravitational instabilities in the disk, or protostellar core fragmentation. Recent searches have uncovered about 15 planetary mass companions to young Sun-like stars in orbits of 50-300 AU from the central star. These objects pose significant challenges for formation theories. One particular object, FW Tau b, may be caught in the process of formation. FW Tau b has an apparent brightness and colors consistent with an early L-dwarf, bright emission lines consistent with strong accretion, heavy K-band veiling due to warm dust, and a spatially resolved jet. However, the object mass is not known because the accretion/disk signatures veil the photosphere and have prevented detection of photospheric features and along with a precise measurement of spectral type or temperature. We propose to use STIS G750L to obtain a deep red-optical spectrum of this very faint and enigmatic object to measure its spectral type and thereby infer its mass. If the photosphere is visible, an M-dwarf SpT would mean that the object is a brown dwarf obscured by an edge-on disk. An L-dwarf SpT would indicate a planetary mass object with strong accretion. If entirely veiled, this object would have a remarkably high accretion rate, consistent with it being caught either in its main formation stage or in outburst. A wealth of data, including HST optical photometry, Keck-AO near-IR spectra, and ALMA observations, all suggest that FW Tau b is a very low mass companion at an important stage of evolution. These STIS data are crucial to finally tie these observations together with a SpT and refined mass estimate of this object. The goal of this program is to obtain a STIS long slit spectrum of a faint secondary located 2.28" away from the primary star. The primary star is an equal-luminosity 0.1 arcsec binary. Step 1: acquire primary star with centroid Step 2: offset to faint secondary Step 3: Integrate (2.5 orbits) Step 1: flux-weighted centroid on a 0.1 arcsec binary over 5x5 arcsec. I think that this should work well to get the centroid of the binary with an error less than the eventual slit width. There's another similar-luminosity source at 12" away, but that should be far enough to not mess up the acquisition. I put in 1.5s, which guarantees excellent S/N without coming close to saturation. Used Pickles MV as a template. Step 2: Offset. I've calculated, re-calculated, and checked several times the offset. Still, it might be useful to check that, e.g., +/- are correct. There's no "offset" button, right, I just put in the correct target coordinate offsets into the Fixed Targets list? Step 3: Integrate; Include flatfield at the end of each visit. ORIENT CONSTRAINT: As stated in the Phase I proposal, we don't want the primary falling at the same location as FW Tau in the cross dispersion direction, even with the 2" separation. The PA is 295.5. So the bad positions are 205.5 and 20.5. Then ORIENT=PA+45, so the bad ORIENT positions are 250 and 65. We have set the VISIT constraints to rule out those slit orientations. The ORIENT constraint is also set so that the slit is not placed along the diffraction spikes from the primary (within 10 degrees). EXTRA-SOLAR PLANETS 12 false false false false false false SUPPORTED STAR PRE-MAIN SEQUENCE STAR NO Position is 2.278 arcsec from primary, PA=295.5, so it's N and W of the primary. J2000 primary for acquisition is R=15.9 STAR M V-IV T TAURI STAR NO Position is from: ibsm24070_drz.fit J2000 STIS/CCD Spectroscopic No No G750L 7751 /private/var/folders/08/p7y5npf11_q32p3p4rv54g1h0000gp/T/OPVisit2668817553256537105.xml 1464177723676 The scheduling data was generated by CASM 24.0. CASM was run in Phase II mode. ORIENT set so that primary does not fall parallel to secondary on the slit. (Tic-Visit :proposal-id 14196 :visit-id "01" :proposal-version -1 :trans-version "20160322" :date "25-May-2016 21:02:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 294864 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14196 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14196 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2896 :al-overhead-at-end 72 :internal-dur-at-end 238 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3229 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14196 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3006 :al-overhead-at-end 72 :internal-dur-at-end 238 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3229 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14196 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3006 :al-overhead-at-end 72 :internal-dur-at-end 617 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3229 :pcs-gap 0 ) true 3 0