6014( 19) - 05/17/96 11:57 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6014 Version: 19 Check-in Date: 17-May-1996 11:52:13 1.Proposal Title: Spectroscopic Observations of Close Binary T Tauri Stars ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Cool Stars GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Andrea Ghez University of California, Los Angeles CoI: Michal Simon State University of New York, Stony Brook N CoI: Russel White University of California, Los Angeles N ------------------------------------------------------------------------------------ 6. Abstract Although the standard model for star formation is based primarily on single stars, we now know that most T Tauri stars are in multiple systems with the majority having separations less than 100 AU. In order to understand the nature and effects of these close companions we propose to carry out a spectroscopic study using the Faint Object Spectrograph of 4 close binary T Tauri star systems that are spectroscopically separable only with HST. Our primary goal of these observations is to determine the spectral type, and hence to estimate the mass of each component star separately. In addition, this spectroscopic analysis will yield valuable information for determining (1) the level of accretion activity independently for each star, (2) whether both stars have the same extinction, and (3) the physical conditions associated with the surrounding gas and dust. ------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 2] Observations Description ------------------------ We propose to take advantage of the high angular resolution of HST to obtain spectra with FOS's red detector of the individual components of four binary star systems with separations ranging from 0."24 to 0."59 (projected seperations of about 35 to 83 AU). Our plan is to observe each component through the 0."09 aperture with the G570H grating(4569 - 6818 Angstroms). For the bright binary GG Tau we also propose to use the G400H grating (3235 - 4781 Angstroms). The planned exposure times are set by requiring a minimum SNR of 20 in each spectra. This spectral coverage will enable us to determine accurate spectral types and measure equivalent widths of the H alpha, H beta, and O I, all of which are useful diagnostics of accretion activity and outflow. Emission features such as the Ca II H and K lines within the blue spectra for the GG Tau system will also be useful signatures of an accretion disk boundary layer and/or chromospheric activity. Observations of each binary star entails two acquisitions, one for the primary star and another for the nearby companion star. We propose to use a conservative 4 or 5 stage ACQ/PEAK series (depending upon the brightness of the system) to acquire the primary star. Once the primary star's spectra is measured, the second star will be acquired by offseting a known distance and then performing an additional critical peak-up. In order to insure the success of these measurements, we have imposed the following criteria in consultation with FOS scientists A. Koratkar and T. Keyes: (1) To insure the initial peak/up finds the primary, we selected only binary stars having expected flux ratios greater than 4 at V (primary/secondary), (2) To allow an accurate offset to the secondary star, the binary separation must be known to 2% accuracy, (3) To prevent the peak-up onto the secondary star from being affected by the primary star's light (due to the PSF of HST), only binaries with separations greater than 0."20 were selected, all of which have an anticipated light contribution due to the primary star at the distance of the secondary star of less than 3% (third column of the table below). The number of orbits listed in the table below are the total for each binary system. The total exposure times for each component (using both gratings) are also given. Seperation Prim. Flux Number of Exposure Time Star (arcsec) at Sec. Orbits (prim & sec) ------------------------------------------ ------------------ GG Tau 0.240 0.03 3 19.5m & 18.0m XZ Tau 0.296 0.01 4 4.3m & 38.7m GH Tau V955 Tau --------------------------------------------------------- --- Real Time Justification ----------------------- None. Calibration Justification ------------------------- None. Additional Comments ------------------- None. ------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Andrea Ghez, UCLA Department of Astronomy, 8979 Math Sciences Building, 405 N. Hilgard Avenue, Los Angeles, CA 90024-1562 Ship Via: UPS Email: ghez@mira.astro.ucla.edu , ------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GG-TAU-A- STAR, T TAURI STAR RA=4H 32M 30.32S +/- 2000 V = 12.2+/-0.5 OFFSET 0.1S,DEC=17D 31' 40.6" +/- TYPE=K7V 0.4",PLATE-ID=000P B-V = 1.3+/-0.5 2 GG-TAU-B STAR, T TAURI STAR R=0.24",PA=1D,FROM 1,PLATE- 2000 V = 16+/-1.5 ID=000P TYPE=M8 B-V = 1.3+/-0.5 Comments: Spectral types and B-V colors are very uncertain. 3 XZ-TAU-A- STAR, T TAURI STAR RA=4H 31M 40.07S +/- 2000 V = 13.3+/-0.5 OFFSET 0.1S,DEC=18D 13' 57.4" +/- TYPE=M3 0.4",PLATE-ID=000P B-V = 1.43 4 XZ-TAU-B STAR, T TAURI STAR R=0.296",PA=327D,FROM 3,PLATE- 2000 V = 15.4+/-0.5 ID=000P TYPE=M6 B-V = 1.43 Comments: Spectral types and B-V colors are very uncertain. 5 GH-TAU-A- STAR,T TAURI STAR, RA=04H 33M 6.23S +/- J2000 V = 13.3+/-0.5 OFFSET 0.1S,DEC=24D 9' 34.3" +/- TYPE=M2 0.4",PLATE-ID=000L B-V = 1.53 Comments: Since the first PEAK-UP may center on the secondary instead of the primary, spectra at two offset positions (+/- sep. of 0.31" at PA of 299D) will be taken (Targets 6 and 7 below). 6 GH-TAU-B STAR,T TAURI STAR, R=0.314",PA=299D,FROM 5 J2000 V = 14.0+/-0.5 TYPE=M4 B-V = 1.53 Comments: Spectral type and B-V color are very uncertain. 7 V955-TAU-A- STAR,T TAURI STAR, RA=4H 42M 7.768S +/- J2000 V = 14.7+/-0.5 OFFSET 0.1S,DEC=25D 23' 12.57" +/- TYPE=M0 0.4",PLATE-ID=005N B-V = 1.77 8 V955-TAU-B STAR,T TAURI STAR, R=0.33",PA=204D,FROM 7 J2000 V = 17.0+/-0.5 TYPE=M6 B-V = 1.77 Comments: Spectral type and B-V color are very uncertain. 9 GH-TAU-C STAR,T TAURI STAR, R=0.314",PA=119D,FROM 5 J2000 V = 14.0+/-0.5 TYPE=M4 B-V = 1.53 Comments: Spectral type and B-V color are very uncertain. 6014( 19) - 05/17/96 11:57 - [ 5] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GG-TAU-A-OF FOS/RD ACQ/PEA 4.3 G570H 5700 SCAN-STEP-Y=1.204,SEARCH-SIZE-X=1 1 1.0S ONBOARD ACQ FOR 5-6 FSET K ,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 2 GG-TAU-A-OF FOS/RD ACQ/PEA 1.0-PAI G570H 5700 SCAN-STEP-X=0.602, 1 1.0S ONBOARD ACQ FOR 5-6 FSET K R-A SCAN-STEP-Y=0.602,SEARCH-SIZE-X=6 ,SEARCH-SIZE-Y=2,STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 3 GG-TAU-A-OF FOS/RD ACQ/PEA 0.25-PA G570H 5700 SCAN-STEP-X=0.172, 1 3.0S ONBOARD ACQ FOR 5-6 FSET K IR-A SCAN-STEP-Y=0.172,SEARCH-SIZE-X=5 ,SEARCH-SIZE-Y=5,STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 4 GG-TAU-A-OF FOS/RD ACQ/PEA 0.1-PAI G570H 5700 SCAN-STEP-X=0.05,SCAN-STEP-Y=0.05 1 3.0S ONBOARD ACQ FOR 5-6 FSET K R-A ,SEARCH-SIZE-X=5,SEARCH-SIZE-Y=5, STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 5 GG-TAU-A-OF FOS/RD ACCUM 0.1-PAI G570H 5700 STEP-PATT=SINGLE 1 390S FSET R-A ------------------------------------------------------------------------------------------------------------------------------------ 6 GG-TAU-A-OF FOS/RD ACCUM 0.1-PAI G400H 4000 STEP-PATT=SINGLE 1 300S EXPAND FSET R-A ------------------------------------------------------------------------------------------------------------------------------------ 7 GG-TAU-B FOS/RD ACQ/PEA 0.1-PAI G570H 5700 SCAN-STEP-X=0.04,SCAN-STEP-Y=0.04 1 45S ONBOARD ACQ FOR 8-9 K R-A ,SEARCH-SIZE-X=3,SEARCH-SIZE-Y=3, STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 8 GG-TAU-B FOS/RD ACCUM 0.1-PAI G570H 5700 STEP-PATT=SINGLE 1 300S R-A ------------------------------------------------------------------------------------------------------------------------------------ 9 GG-TAU-B FOS/RD ACCUM 0.1-PAI G400H 4000 STEP-PATT=SINGLE 1 5M END ORBIT EXPAND R-A ------------------------------------------------------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 6] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 21 XZ-TAU-A-OF FOS/RD ACQ/PEA 4.3 G400H 4000 SCAN-STEP-Y=1.204,SEARCH-SIZE-X=1 1 6.0S ONBOARD ACQ FOR 26 FSET K ,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 22 XZ-TAU-A-OF FOS/RD ACQ/PEA 1.0-PAI G400H 4000 SCAN-STEP-X=0.602, 1 8.0S ONBOARD ACQ FOR 26 FSET K R-A SCAN-STEP-Y=0.602,SEARCH-SIZE-X=6 ,SEARCH-SIZE-Y=2,STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 23 XZ-TAU-A-OF FOS/RD ACQ/PEA 0.5-PAI G400H 4000 SCAN-STEP-X=0.3,SCAN-STEP-Y=0.3, 1 16.0S ONBOARD ACQ FOR 26 FSET K R-A SEARCH-SIZE-X=3,SEARCH-SIZE-Y=3, STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 24 XZ-TAU-A-OF FOS/RD ACQ/PEA 0.25-PA G400H 4000 SCAN-STEP-X=0.172, 1 8.0S ONBOARD ACQ FOR 26 FSET K IR-A SCAN-STEP-Y=0.172,SEARCH-SIZE-X=3 ,SEARCH-SIZE-Y=3,STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 25 XZ-TAU-A-OF FOS/RD ACQ/PEA 0.1-PAI G570H 5700 SCAN-STEP-X=0.05,SCAN-STEP-Y=0.05 1 16.0S ONBOARD ACQ FOR 26 FSET K R-A ,SEARCH-SIZE-X=5,SEARCH-SIZE-Y=5, STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 26 XZ-TAU-A-OF FOS/RD ACCUM 0.1-PAI G570H 5700 STEP-PATT=SINGLE 1 260S EXPAND FSET R-A ------------------------------------------------------------------------------------------------------------------------------------ 28 XZ-TAU-B FOS/RD ACQ/PEA 0.1-PAI G570H 5700 SCAN-STEP-X=0.04,SCAN-STEP-Y=0.04 1 205S ONBOARD ACQ FOR 29 K R-A ,SEARCH-SIZE-X=3,SEARCH-SIZE-Y=3, STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 29 XZ-TAU-B FOS/RD ACCUM 0.1-PAI G570H 5700 STEP-PATT=SINGLE 1 600S END ORBIT EXPAND R-A ------------------------------------------------------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 7] Visit: 03 Visit Requirements: ON HOLD FOR 05 On Hold Comments: Waiting data from WFPC2 imaging. Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 GH-TAU-A-OF FOS/RD ACQ/PEA 4.3 G570H 5700 SCAN-STEP-Y=1.204,SEARCH-SIZE-X=1 1 1.0S ONBOARD ACQ FOR 32 FSET K ,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 32 GH-TAU-A-OF FOS/RD ACQ/PEA 1.0-PAI G570H 5700 SCAN-STEP-X=0.602, 1 1.0S ONBOARD ACQ FOR 33 FSET K R-A SCAN-STEP-Y=0.602,SEARCH-SIZE-X=6 ,SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 33 GH-TAU-A-OF FOS/RD ACQ/PEA 0.25-PA G570H 5700 SCAN-STEP-X=0.172, 1 3.0S ONBOARD ACQ FOR 34 FSET K IR-A SCAN-STEP-Y=0.172,SEARCH-SIZE-X=5 ,SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ 34 GH-TAU-A-OF FOS/RD ACQ/PEA 0.1-PAI G570H 5700 SCAN-STEP-X=0.05,SCAN-STEP-Y=0.05 1 5.0S ONBOARD ACQ FOR 36-38 FSET K R-A ,SEARCH-SIZE-X=5,SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ 36 GH-TAU-A-OF FOS/RD ACCUM 0.1-PAI G570H 5700 1 1200S EXPAND FSET R-A ------------------------------------------------------------------------------------------------------------------------------------ 37 GH-TAU-B FOS/RD ACCUM 0.1-PAI G570H 5700 1 1100S R-A ------------------------------------------------------------------------------------------------------------------------------------ 38 GH-TAU-C FOS/RD ACCUM 0.1-PAI G570H 5700 1 1080S END ORBIT EXPAND NO SPLIT R-A ------------------------------------------------------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 8] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 V955-TAU-A- FOS/RD ACQ/PEA 4.3 G570H 5700 SCAN-STEP-Y=1.204,SEARCH-SIZE-X=1 1 3.0S ONBOARD ACQ FOR 42 OFFSET K ,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 42 V955-TAU-A- FOS/RD ACQ/PEA 1.0-PAI G570H 5700 SCAN-STEP-X=0.602, 1 3.0S ONBOARD ACQ FOR 43 OFFSET K R-A SCAN-STEP-Y=0.602,SEARCH-SIZE-X=6 ,SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 43 V955-TAU-A- FOS/RD ACQ/PEA 0.5-PAI G570H 5700 SCAN-STEP-X=0.29,SCAN-STEP-Y=0.29 1 5S ONBOARD ACQ FOR 44 OFFSET K R ,SEARCH-SIZE-X=3,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 44 V955-TAU-A- FOS/RD ACQ/PEA 0.25-PA G570H 5700 SCAN-STEP-X=0.17,SCAN-STEP-Y=0.17 1 12S ONBOARD ACQ FOR 45 OFFSET K IR-A ,SEARCH-SIZE-X=3,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 45 V955-TAU-A- FOS/RD ACQ/PEA 0.1-PAI G570H 5700 SCAN-STEP-X=0.05,SCAN-STEP-Y=0.05 1 20.0S ONBOARD ACQ FOR 46 OFFSET K R-A ,SEARCH-SIZE-X=5,SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ 46 V955-TAU-A- FOS/RD ACCUM 0.1-PAI G570H 5700 1 600S EXPAND OFFSET R-A ------------------------------------------------------------------------------------------------------------------------------------ 47 V955-TAU-B FOS/RD ACQ/PEA 0.1-PAI G570H 5700 SCAN-STEP-X=0.04,SCAN-STEP-Y=0.04 1 190S ONBOARD ACQ FOR 48 K R-A ,SEARCH-SIZE-X=3,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 48 V955-TAU-B FOS/RD ACCUM 0.1-PAI G570H 5700 1 1800S END ORBIT EXPAND R-A ------------------------------------------------------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 9] Visit: 05 Visit Requirements: ON HOLD On Hold Comments: Pending approval to add WFPC2 to program Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GH-TAU-A-OF WFPC2 IMAGE WFALL F675W 1 2S FSET ------------------------------------------------------------------------------------------------------------------------------------ 6014( 19) - 05/17/96 11:57 - [ 10] Summary Form for Proposal 6014 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCAN-STEP-Y=1.204 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 STEP-PATT=SINGLE SEARCH-SIZE-Y=5 SEARCH-SIZE-X=5 SEARCH-SIZE-X=3 SEARCH-SIZE-Y=2 SCAN-STEP-Y=0.3 SCAN-STEP-Y=0.172 SCAN-STEP-Y=0.05 SCAN-STEP-Y=0.04 SEARCH-SIZE-X=6 SCAN-STEP-X=0.172 SCAN-STEP-X=0.05 SCAN-STEP-Y=0.602 SCAN-STEP-Y=0.29 SCAN-STEP-Y=0.17 SCAN-STEP-X=0.04 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Cool Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 5-6 EXPAND ONBOARD ACQ FOR 8-9 END ORBIT EXPAND ONBOARD ACQ FOR 26 ONBOARD ACQ FOR 29 ON HOLD FOR 05 ONBOARD ACQ FOR 32 ONBOARD ACQ FOR 33 ONBOARD ACQ FOR 34 ONBOARD ACQ FOR 36-38 END ORBIT EXPAND NO SPLIT ONBOARD ACQ FOR 42 ONBOARD ACQ FOR 43 ONBOARD ACQ FOR 44 ONBOARD ACQ FOR 45 ONBOARD ACQ FOR 46 ONBOARD ACQ FOR 48 ON HOLD ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G570H G400H F675W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GG-TAU-A-OFFSET GG-TAU-B XZ-TAU-A-OFFSET XZ-TAU-B GH-TAU-A-OFFSET GH-TAU-B GH-TAU-C V955-TAU-A-OFFSET V955-TAU-B ------------------------------------------------------------------------------------------------------------------------------------