! PI: Andrea Ghez ! Received Fri Feb 9 18:45:27 EST 1996 ! From: whiter@astro.ucla.edu ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6735,v 6.1 1996/08/26 20:27:06 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6735,v 6.1 1996/08/26 20:27:06 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Roman ! Phone: 410-338-4479 , E-mail: aroman@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0889.ghez.prop ! Date generated: Fri Dec 22 18:03:02 EST 1995 ! Proposal_Information ! Section 4 Title: Locating Disks, Accretion Flows, and Outflows in Close Binary T Tauri Stars Proposal_Category: GO Scientific_Category: COOL STARS Cycle: 6 Investigators PI_name: Andrea Ghez PI_Institution: University of California Los Angeles CoI_Name: Michal Simon CoI_Institution: State University of New York, Stony Brook Contact: ! Y or N (designate at most one contact) CoI_Name: Cathie Clarke CoI_Institution: University of Cambridge Contact: ! Y or N (designate at most one contact) CoI_Name: Russel White CoI_Institution: University of California, Los Angeles Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) Although the standard model for star formation is based on single stars, we now know that most T Tauri stars are in multiple star systems with the majority having separations less than 100 AU, the size typically inferred for a circumstellar disk. Planetary Camera (PC) observations of a few T Tauri binary stars in Cycle 4 have revealed a particularly surprising result: contrary to the standard model for T Tauri stars, the secondary stars have ultra-violet (UV) but no infrared (IR) excesses. We interpret this as a signature of diskless accretion, a phenomenon previously unobserved in T Tauri stars. Furthermore, this result suggests that planetary formation is unlikely to occur around these close secondary stars. In Cycle 6, we propose to use the Planetary Camera aboard HST to carry out a high resolution imaging survey of T Tauri binary stars at a variety of wavelengths. These observations will reveal whether diskless accretion onto close (<= 100 AU) secondary stars is the norm. This would indicate the accretion of material with low angular momentum compared to the binary star and would thereby constrain binary star formation models. An additional outcome of this study is a unique test of the theoretical pre-main sequence tracks, as the components of close binary T Tauri stars are approximately coeval. Questions ! Free format text (please update) Observing_Description: We propose to use the Planetary Camera to image the individual components of 12 close T Tauri binary star systems through the six HST filters, F336W, F439W, F555W, F675W, F814W, F656N. The first 5 filters are the broad band filter approximations to Johnson Cousins UBVRI system as recommended in the WFPC2 Instrument Handbook (Version 3.0, June 1995). The F656N is a narrow band fiter optimized for imaging the Halpha emission feature. Since the broad band filters yield a simultaneous characterization of the underlying continuum, the intensity of this emission feature can be estimated from these measurements. In order to obtain the high spatial resolution necessary to image binary stars with separations as small as 0."1, we (1) request the fine-lock guiding mode and (2) intend to take two sets of exposures for each source, where the second set is offset by 10.5 pixels in the x and y directions from the first set. The proposed observations for each object in each filter are identical except for the exposure times. The exposure times for the broadband filters were set to fill the CCD wells to 1/4 capacity based on WFPC2 specifications for system throughput, point spread function, and CCD charactersitics (pg. 66, WFPC2 Instrument Handbook) using the available unresolved UBRVI data for each source (which somewhat overestimates the individual component fluxes). The exposure times for the F336W filters were, for some sources, dropped below that needed to yield 1/4 well capacity due to orbital constraints, but nevertheless kept above a signal-to-noise ratio of 100. The observations for each target (i.e., each visit) fill 1 - 2 orbits depending on the object's brightness. Several fields (FV Tau, GH Tau & V955 Tau) actually contain other close binary systems within the field of view of the Planetary Camera. For these systems we plan to center the chip on a position halfway between the wide pair. Real_Time_Justification: None Calibration_Justification: None Additional_Comments: None !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: FO-TAU Alternate_Names: HBC369 Description: STAR, T TAURI STAR Position: RA=4H 14M 49.25S +/- 0.02S, ! Most common format is DEC=+28D 12' 31.31" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=00DG ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=15.0 +/- 0.5 ! Include at least V and B-V TYPE=M2 B-V=0.3 +/- 0.5 Comments: Fixed_Targets Target_Number: 3 Target_Name: FS-TAU Alternate_Names: HBC383 Description: STAR, T TAURI STAR Position: RA=4H 22M 02.19S +/- 0.02S, ! Most common format is DEC=+26D 57' 30.93" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=000L ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=15.7 +/- 0.5 ! Include at least V and B-V TYPE=M1 B-V=1.6 +/- 0.5 Comments: Fixed_Targets Target_Number: 4 Target_Name: FV-TAU Alternate_Names: HBC386 Description: STAR, T TAURI STAR Position: RA=4H 26M 53.99S +/- 0.02S, ! Most common format is DEC=+26D 06' 53.34" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=000L ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=15.4 +/- 0.5 ! Include at least V and B-V TYPE=K5 B-V=1.7 +/- 0.5 Comments: The position is the mid-position between FV Tau and FV Tau/c (sep ~12.3"). Both are close binary T Tauri Stars. Fixed_Targets Target_Number: 5 Target_Name: FW-TAU Alternate_Names: Description: STAR, T TAURI STAR Position: RA=4H 29M 29.71S +/- 0.02S, ! Most common format is DEC=+26D 16' 53.54" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=000L ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=15.4 +/- 0.5 ! Include at least V and B-V TYPE=M4 B-V=1.7 +/- 0.5 Comments: Fixed_Targets Target_Number: 6 Target_Name: XZ-TAU Alternate_Names: HBC50 Description: STAR, T TAURI STAR Position: RA=4H 31M 40.09S +/- 0.02S, ! Most common format is DEC=+18D 13' 57.15" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=000P ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=14.3 +/- 0.5 ! Include at least V and B-V TYPE=M3 B-V=1.3 +/- 0.5 Comments: Fixed_Targets Target_Number: 7 Target_Name: FY-TAU Alternate_Names: HBC401 Description: STAR, T TAURI STAR Position: RA=4H 32M 30.59S +/- 0.02S, ! Most common format is DEC=+24D 19' 57.34" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=000L ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=15.4 +/- 0.5 ! Include at least V and B-V TYPE=M0 B-V=1.7 +/- 0.5 Comments: Fixed_Targets Target_Number: 8 Target_Name: GH-TAU Alternate_Names: HBC55 Description: STAR, T TAURI STAR Position: RA=4H 33M 06.41S +/- 0.02S, ! Most common format is DEC=+24D 09' 45.60" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=000L ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=12.95 +/- 0.5 ! Include at least V and B-V TYPE=M2 B-V=1.5 +/- 0.5 Comments: The position is the mid-position between GH Tau and V807 Tau (sep ~21.4"). Both are close binary T Tauri Stars. Since V807 is ~1.5mag brighter than GH Tau, we set the exposure times to achieve 1/8 well for GH and doubled the number of our F656N exposures. Fixed_Targets Target_Number: 9 Target_Name: IS-TAU Alternate_Names: HBC59 Description: STAR, T TAURI STAR Position: RA=4H 33M 36.78S +/- 0.02S, ! Most common format is DEC=+26D 09' 49.44" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=000L ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=14.3 +/- 0.5 ! Include at least V and B-V TYPE=K2 B-V=2.0 +/- 0.5 Comments: Fixed_Targets Target_Number: 11 Target_Name: V955-TAU Alternate_Names: HBC69 Description: STAR, T TAURI STAR Position: RA=4H 42M 07.55S +/- 0.02S, ! Most common format is DEC=+25D 23' 08.22" +/- 0.1", ! RA=0H 0M 0.00S +/- 0S, PLATE-ID=005N ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=14.74 +/- 0.5 ! Include at least V and B-V TYPE=K7 B-V=1.8 +/- 0.5 Comments: The position is the mid-position between V955 Tau and LkHa 332/G1 (sep ~14.5"). Both are close binary T Tauri Stars. ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Visits ! Section 6 Visit_Number: 1 Visit_Requirements: ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! PCS MODE [Fine | Gyro] ! GUIDing TOLerance ! DROP TO GYRO IF NECESSARY [NO REACQuisition] ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! SCHEDulability ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN