12361( 3) - 11-Oct-2010 15:20:46 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12361 Version: 3 Check-in Time: 11-Oct-2010 15:20:46 STScI Edit Number: 2 Title Chandra X-ray and HST/COS+STIS UV Spectroscopy of Low-Mass Stars in the 9 Myr Old TW Hya Association ------------------------------------------------------------------------------------ Type Cycle GO 18 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Alexander Brown University of Colorado at Boulder CoI: Dr. Kevin France University of Colorado at Boulder N CoI: Dr. Thomas R. Ayres University of Colorado at Boulder N CoI: Dr. Joanna M. Brown Max-Planck-Institut fur extraterrestrische N Physik CoI: Dr. Gregory J. Herczeg Max-Planck-Institut fur extraterrestrische N Physik ------------------------------------------------------------------------------------ Abstract The TW Hya association (age ~ 9 Myr, distances ~ 50 pc) is the nearest group of young stars with ages < 10 Myr and has stars with both actively accreting and debris disks. Consequently, this association offers special opportunities for studying protoplanetary system evolution. We propose to study low mass TWA members using Chandra ACIS-S to obtain CCD resolution X-ray spectra and the HST COS+STIS spectrographs to obtain medium resolution FUV and NUV spectra. Using these spectra we will study the temperature/EM distributions of the hot (log T = 4-7 K) plasma, examine the flows and turbulence in the hot plasma, and construct the full X-ray/EUV/FUV radiation fields to allow modeling their influence on protoplanetary system physics and chemistry. [ Chandra and HST time awarded to observe the common proper motion pair TWA 13 A + 13B.] ------------------------------------------------------------------------------------ Observations Description ------------------------ Two TWA Association members are to be observed using COS G130M/G160M and the brighter will also be observed using STIS G230L and E230M. These stars are a common proper motion pair separated by ~ 5 arcseconds. Both are M1 dwarfs and have V magnitudes of 11.5 (TWA13A) and 12.0 (TWA13B). No UV spectra exist for TWA 13 A+B. Therefore, we have constructed our Phase II observing sequence to match successfully implemented COS/STIS observations for young stars with similar properties and brightness by Cycle 17 program 11616. N.B. we are using exposure times and settings matching those for stars that have ALREADY been observed by 11616, such as GM Aur (V=12.2), RECX-11 (V=11.2), and RECX-1 (V=10.5), that span a magnitude range encompassing the TWA 13 stars. TWA 13 is old enough that the stars are no longer accreting and do not have circumstellar disks; thus their UV continuum will not show variability due to variable accretion. The coordinates given in this Phase II proposal are from the 2MASS Catalog and are already corrected for proper motion to 2000.0. The proper motions are relatively small and are the most accurate currently available from the as yet 12361( 3) - 11-Oct-2010 15:20:46 - [ 2] unpublished work of Mamajek. The positions and proper motions are accurate enough that the positional error for TWA 13A will be far less than 1 arcsecond and there should be no chance of acquiring TWA 13B by mistake. We acquire TWA 13A using a COS ACQ/IMAGE with MIRRORB and the PSA, and then obtain four G130M exposures in the rest of Orbit 1.Orbit 2 is used for three G160M exposures. Orbit 3 starts with an offset to TWA 13B and then contains four G130M exposures, while orbit 4 is used for three G160M exposures. Orbit 5 starts with a STIS acquisition of TWA 13A and then obtains G230L and E230M spectra with the NUV-MAMA. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12361( 3) - 11-Oct-2010 15:20:46 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 TWA13-OFFSET STAR, M V-IV, PRE-MAIN RA-OFF=+0.218S +/- 0.1S, J2000 V = 12.1 +/- 0.1 SEQUENCE STAR DEC-OFF=-4.28" +/- 0.1", FROM 1 Reference Frame: ICRS Comments: Common proper motion companion to TWA13A. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0 -0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1 TWA13A STAR, M V-IV, PRE-MAIN RA=11H21M17.2400S +/- 0.1", J2000 V = 11.5 +/- 0.01 SEQUENCE STAR DEC=-34D46'45.49" +/- 0.1" Reference Frame: ICRS Comments: Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 -0.005470632794213105 -0.0170 0.0172 ------------------------------------------------------------------------------------------------------------------------------------ 12361( 3) - 11-Oct-2010 15:20:46 - [ 4] Visit: 01 Visit Requirements: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 TWA13A COS/NUV ACQ/IMA PSA MIRRORB 1 60 S GE ------------------------------------------------------------------------------------------------------------------------------------ 2 TWA13A COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=390, FP-POS=1 1 500 S G ------------------------------------------------------------------------------------------------------------------------------------ 3 TWA13A COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=400, FP-POS=4 1 510 S G ------------------------------------------------------------------------------------------------------------------------------------ 4 TWA13A COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=390, FP-POS=1 1 500 S G ------------------------------------------------------------------------------------------------------------------------------------ 5 TWA13A COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=375, FP-POS=4 1 485 S G ------------------------------------------------------------------------------------------------------------------------------------ 6 TWA13A COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=750, FP-POS=3 1 860 S G ------------------------------------------------------------------------------------------------------------------------------------ 7 TWA13A COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=750, FP-POS=4, 1 860 S G SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ 8 TWA13A COS/FUV TIME-TA PSA G160M 1623 BUFFER-TIME=750, FP-POS=3, 1 860 S G SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ 9 TWA13-OFFSE COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=535, FP-POS=1 1 645 S T G ------------------------------------------------------------------------------------------------------------------------------------ 10 TWA13-OFFSE COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=515, FP-POS=4 1 625 S T G ------------------------------------------------------------------------------------------------------------------------------------ 11 TWA13-OFFSE COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=535, FP-POS=1 1 645 S T G ------------------------------------------------------------------------------------------------------------------------------------ 12 TWA13-OFFSE COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=515, FP-POS=4 1 625 S T G ------------------------------------------------------------------------------------------------------------------------------------ 13 TWA13-OFFSE COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=760, FP-POS=3, 1 870 S T G SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ 14 TWA13-OFFSE COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=760, FP-POS=4, 1 870 S T G SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ 12361( 3) - 11-Oct-2010 15:20:46 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 TWA13-OFFSE COS/FUV TIME-TA PSA G160M 1623 BUFFER-TIME=750, FP-POS=3 1 860 S T G ------------------------------------------------------------------------------------------------------------------------------------ 16 TWA13A STIS/CCD ACQ F28X50OII MIRROR 1 10 S I ------------------------------------------------------------------------------------------------------------------------------------ 17 TWA13A STIS/NUV ACCUM 52X0.2 G230L 2376 1 500 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 18 TWA13A STIS/NUV TIME-TA 0.2X0.2 E230M 2561 BUFFER-TIME=1500 1 1410 S -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 19 WAVE STIS/NUV ACCUM 0.2X0.2 E230M 2561 1 25 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ TWA13A 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE TWA13A 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G TWA13A 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G TWA13A 4 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 N/A G TWA13A 5 COS/FUV TIME-TA PSA G130M 1327 none none none none 1 N/A G TWA13A 6 COS/FUV TIME-TA PSA G160M 1577 none none none none 2 N/A G TWA13A 7 COS/FUV TIME-TA PSA G160M 1600 none none none none 2 N/A G TWA13A 8 COS/FUV TIME-TA PSA G160M 1623 none none none none 2 N/A G TWA13-OFFSET 9 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G TWA13-OFFSET 10 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G TWA13-OFFSET 11 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 N/A G TWA13-OFFSET 12 COS/FUV TIME-TA PSA G130M 1327 none none none none 3 N/A G TWA13-OFFSET 13 COS/FUV TIME-TA PSA G160M 1577 none none none none 4 N/A G 12361( 3) - 11-Oct-2010 15:20:46 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ TWA13-OFFSET 14 COS/FUV TIME-TA PSA G160M 1600 none none none none 4 N/A G TWA13-OFFSET 15 COS/FUV TIME-TA PSA G160M 1623 none none none none 4 N/A G TWA13A 16 STIS/CCD ACQ F28X50OI MIRROR none none none none 5 N/A II TWA13A 17 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 5 N/A -MAMA TWA13A 18 STIS/NUV TIME-TA 0.2X0.2 E230M 2561 none none none none 5 N/A -MAMA G WAVE 19 STIS/NUV ACCUM 0.2X0.2 E230M 2561 none none none none 5 N/A -MAMA 12361( 3) - 11-Oct-2010 15:20:46 - [ 7] Summary Form for Proposal 12361 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 0.2X0.2, 52X0.2, F28X50OIII, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV, STIS/CCD, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1500, BUFFER-TIME=375, BUFFER-TIME=390, BUFFER-TIME=400, BUFFER-TIME=515, BUFFER-TIME=535, BUFFER-TIME=750, BUFFER-TIME=760, FP-POS=1, FP-POS=3, FP-POS=4, SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements E230M, G130M, G160M, G230L, MIRROR, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names TWA13-OFFSET, TWA13A, WAVE ------------------------------------------------------------------------------------------------------------------------------------