10828( 7) - 01/03/07 11:56 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10828 Version: 7 Check-in Time: 03-Jan-2007 16:56:03 STScI Edit Number: 1 Title Debris Disks Around Nearby Young M Dwarfs ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 15 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Michael C. Liu University of Hawaii CoI: Dr. David R. Ardila California Institute of Technology N ------------------------------------------------------------------------------------ Abstract We propose to obtain HST/ACS F606W coronagraphic imaging of two young (10--50 Myr), nearby (25--55 pc) M dwarfs to resolve their debris disks in scattered light. Little is known about debris disks around M dwarfs, as very few examples are known and only one, the AU Mic debris disk, has been spatially resolved thus far. IR/sub-mm photometry of our targets indicate large quantities of exceptionally cold dust, comparable to the prototype AU Mic system, and make them excellent candidates for resolved studies with physical resolutions of 1-2 AU. HST/ACS provides an excellent capability for detection of disks in scattered light. Modeling the disk images will allow us to quantify the radial and vertical structure and to search for disk sub- structure, a potential probe of the planet formation process in these young systems. Our program can expand the census of young resolved debris disks, of which very few are currently known. M dwarfs have been largely over-looked in myriad imaging searches: our program will complement the many current programs focusing on the higher-mass AFGK stars. Because our targets belong to nearby young moving groups with known resolved disks around higher mass stars, a key potential outcome of our program is comparative study of coeval debris disks over a range of stellar masses. ------------------------------------------------------------------------------------ 10828( 7) - 01/03/07 11:56 - [ 2] Observations Description ------------------------ We will use the ACS/HRC coronagraph with the 0.9'' mask to resolve disks around two M dwarfs. For each target and PSF reference star we will take short, non- coronagraphic, and long (one orbit each) coronagraphic exposures. The PSF reference star is a star of the same spectral type but brighter and as spatially close to the target as possible. The coronagraphic observations will be done using the F606W filter, which is well calibrated and has been used in the past for this kind of work. Target acquisition is done in a narrow-band filter to avoid saturation. For each target, two orbits are necessary, one for the target and the other for the PSF reference. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10828( 7) - 01/03/07 11:56 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GJ-182 STAR, M V-IV RA=04H59M34.8328S +/- 0.1", J2000 V = 10.1 DEC=+01D47'0.68" +/- 0.1" Reference Frame: ICRS Comments: Hipparcos Coordinates V=10.1 B-V=1.37 (Ground-based) Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.03715 -0.09394 0.0 2 TWA-7 STAR, M V-IV RA=10H42M30.0640S +/- 0.1", J2000 V = 11.06 DEC=-33D40'16.62" +/- 0.1" Reference Frame: ICRS Comments: Tycho Coordinates V=11.65 B-V=1.46 (ground based) Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 -0.00975 -0.0293 0.0 3 GJ1135 STAR, M V-IV RA=10H41M9.3260S +/- 0.1", DEC=- J2000 V = 10.0+/-0.05 36D53'43.58" +/- 0.1" Reference Frame: ICRS Comments: Hipparcos Coordinates V=10 B-V=1.465 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0139 -0.1936 0.0 4 HD30756 STAR, M V-IV RA=04H50M10.2428S +/- 0.1", J2000 V = 8.17 DEC=-05D12'41.47" +/- 0.1" Reference Frame: ICRS Comments: Hipparcos Coordinates V=8.17 No ground based or other photometric measurements. Bt-Vt=1.538 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.00673 0.00213 0.0 10828( 7) - 01/03/07 11:56 - [ 4] Visit: 01 Visit Priority: 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 GJ-182 ACS/HRC ACCUM HRC F606W GAIN=4 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 2 GJ-182 ACS/HRC ACQ HRC-ACQ F660N 1 1 S ------------------------------------------------------------------------------------------------------------------------------------ 3 GJ-182 ACS/HRC ACCUM HRC-CORON F606W CR-SPLIT=4,PAREXP=NONE 1 2000 S USE OFFSET 108281 1.8 see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ GJ-182 1 ACS/HRC ACCUM HRC F606W none none none 1 1 N/A GJ-182 1 ACS/HRC ACCUM HRC F606W none none none 2 1 N/A GJ-182 2 ACS/HRC ACQ HRC-ACQ F660N none none none none 1 N/A GJ-182 3 ACS/HRC ACCUM HRC-CORO F606W none none none 1 1 531.0 S N1.8 GJ-182 3 ACS/HRC ACCUM HRC-CORO F606W none none none 2 1 531.0 S N1.8 GJ-182 3 ACS/HRC ACCUM HRC-CORO F606W none none none 3 1 531.0 S N1.8 GJ-182 3 ACS/HRC ACCUM HRC-CORO F606W none none none 4 1 531.0 S N1.8 10828( 7) - 01/03/07 11:56 - [ 5] Visit: 02 Visit Priority: Visit Requirements: AFTER 01 BY 0.8 Orbits TO 1.2 Orbits 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 HD30756 ACS/HRC ACQ HRC-ACQ F660N 1 1 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD30756 ACS/HRC ACCUM HRC-CORON F606W CR-SPLIT=4,PAREXP=NONE 1 2000 S USE OFFSET 108212 1.8 see below ------------------------------------------------------------------------------------------------------------------------------------ 3 HD30756 ACS/HRC ACCUM HRC F606W GAIN=4 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD30756 1 ACS/HRC ACQ HRC-ACQ F660N none none none none 1 N/A HD30756 2 ACS/HRC ACCUM HRC-CORO F606W none none none 1 1 539.0 S N1.8 HD30756 2 ACS/HRC ACCUM HRC-CORO F606W none none none 2 1 539.0 S N1.8 HD30756 2 ACS/HRC ACCUM HRC-CORO F606W none none none 3 1 539.0 S N1.8 HD30756 2 ACS/HRC ACCUM HRC-CORO F606W none none none 4 1 539.0 S N1.8 HD30756 3 ACS/HRC ACCUM HRC F606W none none none 1 1 N/A HD30756 3 ACS/HRC ACCUM HRC F606W none none none 2 1 N/A 10828( 7) - 01/03/07 11:56 - [ 6] Visit: 03 Visit Priority: 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 TWA-7 ACS/HRC ACCUM HRC F606W GAIN=4 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 2 TWA-7 ACS/HRC ACQ HRC-ACQ F660N 1 1 S ------------------------------------------------------------------------------------------------------------------------------------ 3 TWA-7 ACS/HRC ACCUM HRC-CORON F606W CR-SPLIT=4,PAREXP=NONE 1 2000 S USE OFFSET 108283 1.8 see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ TWA-7 1 ACS/HRC ACCUM HRC F606W none none none 1 1 N/A TWA-7 1 ACS/HRC ACCUM HRC F606W none none none 2 1 N/A TWA-7 2 ACS/HRC ACQ HRC-ACQ F660N none none none none 1 N/A TWA-7 3 ACS/HRC ACCUM HRC-CORO F606W none none none 1 1 536.0 S N1.8 TWA-7 3 ACS/HRC ACCUM HRC-CORO F606W none none none 2 1 536.0 S N1.8 TWA-7 3 ACS/HRC ACCUM HRC-CORO F606W none none none 3 1 536.0 S N1.8 TWA-7 3 ACS/HRC ACCUM HRC-CORO F606W none none none 4 1 536.0 S N1.8 10828( 7) - 01/03/07 11:56 - [ 7] Visit: 04 Visit Priority: Visit Requirements: AFTER 03 BY 0.8 Orbits TO 1.2 Orbits 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 GJ1135 ACS/HRC ACQ HRC-ACQ F660N 1 1 S ------------------------------------------------------------------------------------------------------------------------------------ 2 GJ1135 ACS/HRC ACCUM HRC-CORON F606W CR-SPLIT=4,PAREXP=NONE 1 1500 S USE OFFSET 108214 1.8 see below ------------------------------------------------------------------------------------------------------------------------------------ 3 GJ1135 ACS/HRC ACCUM HRC F606W GAIN=4 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ GJ1135 1 ACS/HRC ACQ HRC-ACQ F660N none none none none 1 N/A GJ1135 2 ACS/HRC ACCUM HRC-CORO F606W none none none 1 1 546.0 S N1.8 GJ1135 2 ACS/HRC ACCUM HRC-CORO F606W none none none 2 1 546.0 S N1.8 GJ1135 2 ACS/HRC ACCUM HRC-CORO F606W none none none 3 1 546.0 S N1.8 GJ1135 2 ACS/HRC ACCUM HRC-CORO F606W none none none 4 1 546.0 S N1.8 GJ1135 3 ACS/HRC ACCUM HRC F606W none none none 1 1 N/A GJ1135 3 ACS/HRC ACCUM HRC F606W none none none 2 1 N/A 10828( 7) - 01/03/07 11:56 - [ 8] Summary Form for Proposal 10828 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures HRC HRC-ACQ HRC-CORON1.8 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters GAIN=4 CR-SPLIT=4 PAREXP=NONE ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements USE OFFSET 108281; AFTER 01 BY 0.8 Orbits TO 1.2 Orbits; USE OFFSET 108212; USE OFFSET 108283; AFTER 03 BY 0.8 Orbits TO 1.2 Orbits; USE OFFSET 108214; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W F660N ------------------------------------------------------------------------------------------------------------------------------------ Target Names GJ-182 HD30756 TWA-7 GJ1135 ------------------------------------------------------------------------------------------------------------------------------------