11204( 2) - 04/24/07 08:59 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11204 Version: 2 Check-in Time: 24-Apr-2007 12:59:20 STScI Edit Number: 0 Title Imaging Circumstellar Disks and Envelopes around Proto-Brown Dwarfs ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Kevin Luhman The Pennsylvania State University CoI: Dr. Nuria Calvet University of Michigan N ------------------------------------------------------------------------------------ Abstract Using the Spitzer Space Telescope, we have discovered two young brown dwarfs with Class I spectral energy distributions (i.e., proto-brown dwarfs). We propose to perform broad-band NICMOS imaging of these Class I brown dwarfs to spatially resolve their circumstellar disks and envelopes. If successful, these data would comprise the first measurements of this kind for brown dwarfs and would provide fundamental constraints on models for the formation of brown dwarfs. ------------------------------------------------------------------------------------ 11204( 2) - 04/24/07 08:59 - [ 2] Observations Description ------------------------ We will obtain NIC2 images of 2 protostellar brown dwarfs in the Chamaeleon star-forming region through the F110W, F160W, and F205W filters. These filters are selected because they provide contiguous broad-band near-IR photometry. Each target will be observed in a 6-point dither pattern (NIC-SPIRAL-DITH) that is centered in the NIC2 array. To optimize the sampling of the PSF, we select a subpixel dither spacing of 60.5 pixels, or 4.56775". At each dither position, we will obtain one MULTIACCUM image in each of the 3 filters. The exposure times of the individual images will be 128, 128, and 96 sec in F110W, F160W, and F205W, respectively, which will provide sufficient signal-to-noise for extended emission based on the results from program 7413 for IRAS 04325+2402 C (Hartmann et al. 1999) and the magnitudes of our 2 targets (H=15.3 and 15.2, K_s=13.9 and 13.8). Because the target areas contain only faint sources, we use one of the SPARS modes for SAMP-SEQ. The combination of SPARS16 and NSAMP=10 provides sufficient samples (8-10) for good cosmic ray rejection. Immediately before and after the dither sequence on each target, we will obtain one image in F205W at a position 30" from the target to measure the background. These two chop positions will be on opposite sides of the target. During the exposures with NIC2, we will obtain parallel images with NIC1 through the F160W filter with the maximum exposure times that do not interfere with the NIC2 observations. Each target will be observed in one orbit and one visit. There are no scheduling constraints for this program. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11204( 2) - 04/24/07 08:59 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CHA25174 STAR, BROWN DWARF, T RA=11H07M3.6930S +/- 0.1", DEC=- J2000 H=15.2 TAURI STAR, 77D24'30.71" +/- 0.1" PROTOPLANETARY DISK Reference Frame: ICRS 2 CHA4146 STAR, BROWN DWARF, RA=11H06M29.4260S +/- 0.1", J2000 H=15.2 PROTOPLANETARY DISK, T DEC=-77D24'58.64" +/- 0.1" TAURI STAR Reference Frame: ICRS 11204( 2) - 04/24/07 08:59 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type NIC-SPIRAL-DITH Pattern_Purpose DITHER Number_Of_Points 6 Point_Spacing 4.56775 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 0.0 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 11204( 2) - 04/24/07 08:59 - [ 5] 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 CHA25174 NIC2 MULTIAC NIC2-FIX F205W SAMP-SEQ=SPARS16,NSAMP=8 1 DEF POS TARG 30, 0; PAR 2 CUM WITH 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=7 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 CHA25174 NIC2 MULTIAC NIC2-FIX F110W SAMP-SEQ=SPARS16,NSAMP=10 1 DEF PATTERN 1 3-8; PAR 6-8 CUM WITH 3-5 ------------------------------------------------------------------------------------------------------------------------------------ 4 CHA25174 NIC2 MULTIAC NIC2-FIX F160W SAMP-SEQ=SPARS16,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 CHA25174 NIC2 MULTIAC NIC2-FIX F205W SAMP-SEQ=SPARS16,NSAMP=8 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=9 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=9 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 8 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=9 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 CHA25174 NIC2 MULTIAC NIC2-FIX F205W SAMP-SEQ=SPARS16,NSAMP=8 1 DEF POS TARG -30, 0; PAR 10 CUM WITH 9 ------------------------------------------------------------------------------------------------------------------------------------ 10 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=7 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CHA25174 1 NIC2 MULTIAC NIC2-FIX F205W none none none none 1 N/A CUM ANY 2 NIC1 MULTIAC NIC1 F160W none none none none 1 N/A CUM 11204( 2) - 04/24/07 08:59 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CHA25174 3 NIC2 MULTIAC NIC2-FIX F110W 1 none none none 1 N/A CUM CHA25174 3 NIC2 MULTIAC NIC2-FIX F110W 2 none none none 1 N/A CUM CHA25174 3 NIC2 MULTIAC NIC2-FIX F110W 3 none none none 1 N/A CUM CHA25174 3 NIC2 MULTIAC NIC2-FIX F110W 4 none none none 1 N/A CUM CHA25174 3 NIC2 MULTIAC NIC2-FIX F110W 5 none none none 1 N/A CUM CHA25174 3 NIC2 MULTIAC NIC2-FIX F110W 6 none none none 1 N/A CUM CHA25174 4 NIC2 MULTIAC NIC2-FIX F160W 1 none none none 1 N/A CUM CHA25174 4 NIC2 MULTIAC NIC2-FIX F160W 2 none none none 1 N/A CUM CHA25174 4 NIC2 MULTIAC NIC2-FIX F160W 3 none none none 1 N/A CUM CHA25174 4 NIC2 MULTIAC NIC2-FIX F160W 4 none none none 1 N/A CUM CHA25174 4 NIC2 MULTIAC NIC2-FIX F160W 5 none none none 1 N/A CUM CHA25174 4 NIC2 MULTIAC NIC2-FIX F160W 6 none none none 1 N/A CUM CHA25174 5 NIC2 MULTIAC NIC2-FIX F205W 1 none none none 1 N/A CUM CHA25174 5 NIC2 MULTIAC NIC2-FIX F205W 2 none none none 1 N/A CUM CHA25174 5 NIC2 MULTIAC NIC2-FIX F205W 3 none none none 1 N/A CUM CHA25174 5 NIC2 MULTIAC NIC2-FIX F205W 4 none none none 1 N/A CUM CHA25174 5 NIC2 MULTIAC NIC2-FIX F205W 5 none none none 1 N/A CUM CHA25174 5 NIC2 MULTIAC NIC2-FIX F205W 6 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 1 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 2 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 3 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 4 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 5 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 6 none none none 1 N/A CUM 11204( 2) - 04/24/07 08:59 - [ 7] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ANY 7 NIC1 MULTIAC NIC1 F160W 1 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 2 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 3 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 4 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 5 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 6 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 1 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 2 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 3 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 4 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 5 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 6 none none none 1 N/A CUM CHA25174 9 NIC2 MULTIAC NIC2-FIX F205W none none none none 1 N/A CUM ANY 10 NIC1 MULTIAC NIC1 F160W none none none none 1 N/A CUM 11204( 2) - 04/24/07 08:59 - [ 8] Visit: 02 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 CHA4146 NIC2 MULTIAC NIC2-FIX F205W SAMP-SEQ=SPARS16,NSAMP=8 1 DEF POS TARG 30, 0; PAR 2 CUM WITH 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=7 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 CHA4146 NIC2 MULTIAC NIC2-FIX F110W SAMP-SEQ=SPARS16,NSAMP=10 1 DEF PATTERN 1 3-8; PAR 6-8 CUM WITH 3-5 ------------------------------------------------------------------------------------------------------------------------------------ 4 CHA4146 NIC2 MULTIAC NIC2-FIX F160W SAMP-SEQ=SPARS16,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 CHA4146 NIC2 MULTIAC NIC2-FIX F205W SAMP-SEQ=SPARS16,NSAMP=8 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=9 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=9 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 8 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=9 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 CHA4146 NIC2 MULTIAC NIC2-FIX F205W SAMP-SEQ=SPARS16,NSAMP=8 1 DEF POS TARG -30, 0; PAR 10 CUM WITH 9 ------------------------------------------------------------------------------------------------------------------------------------ 10 ANY NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS16,NSAMP=7 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CHA4146 1 NIC2 MULTIAC NIC2-FIX F205W none none none none 1 N/A CUM ANY 2 NIC1 MULTIAC NIC1 F160W none none none none 1 N/A CUM 11204( 2) - 04/24/07 08:59 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ CHA4146 3 NIC2 MULTIAC NIC2-FIX F110W 1 none none none 1 N/A CUM CHA4146 3 NIC2 MULTIAC NIC2-FIX F110W 2 none none none 1 N/A CUM CHA4146 3 NIC2 MULTIAC NIC2-FIX F110W 3 none none none 1 N/A CUM CHA4146 3 NIC2 MULTIAC NIC2-FIX F110W 4 none none none 1 N/A CUM CHA4146 3 NIC2 MULTIAC NIC2-FIX F110W 5 none none none 1 N/A CUM CHA4146 3 NIC2 MULTIAC NIC2-FIX F110W 6 none none none 1 N/A CUM CHA4146 4 NIC2 MULTIAC NIC2-FIX F160W 1 none none none 1 N/A CUM CHA4146 4 NIC2 MULTIAC NIC2-FIX F160W 2 none none none 1 N/A CUM CHA4146 4 NIC2 MULTIAC NIC2-FIX F160W 3 none none none 1 N/A CUM CHA4146 4 NIC2 MULTIAC NIC2-FIX F160W 4 none none none 1 N/A CUM CHA4146 4 NIC2 MULTIAC NIC2-FIX F160W 5 none none none 1 N/A CUM CHA4146 4 NIC2 MULTIAC NIC2-FIX F160W 6 none none none 1 N/A CUM CHA4146 5 NIC2 MULTIAC NIC2-FIX F205W 1 none none none 1 N/A CUM CHA4146 5 NIC2 MULTIAC NIC2-FIX F205W 2 none none none 1 N/A CUM CHA4146 5 NIC2 MULTIAC NIC2-FIX F205W 3 none none none 1 N/A CUM CHA4146 5 NIC2 MULTIAC NIC2-FIX F205W 4 none none none 1 N/A CUM CHA4146 5 NIC2 MULTIAC NIC2-FIX F205W 5 none none none 1 N/A CUM CHA4146 5 NIC2 MULTIAC NIC2-FIX F205W 6 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 1 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 2 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 3 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 4 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 5 none none none 1 N/A CUM ANY 6 NIC1 MULTIAC NIC1 F160W 6 none none none 1 N/A CUM 11204( 2) - 04/24/07 08:59 - [ 10] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ANY 7 NIC1 MULTIAC NIC1 F160W 1 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 2 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 3 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 4 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 5 none none none 1 N/A CUM ANY 7 NIC1 MULTIAC NIC1 F160W 6 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 1 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 2 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 3 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 4 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 5 none none none 1 N/A CUM ANY 8 NIC1 MULTIAC NIC1 F160W 6 none none none 1 N/A CUM CHA4146 9 NIC2 MULTIAC NIC2-FIX F205W none none none none 1 N/A CUM ANY 10 NIC1 MULTIAC NIC1 F160W none none none none 1 N/A CUM 11204( 2) - 04/24/07 08:59 - [ 11] Summary Form for Proposal 11204 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures NIC2-FIX NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC2 NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMP-SEQ=SPARS16 NSAMP=8 NSAMP=7 NSAMP=10 NSAMP=9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 30, 0; PAR 2 WITH 1; PATTERN 1 3-8; PAR 6-8 WITH 3-5; POS TARG -30, 0; PAR 10 WITH 9; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F205W F160W F110W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CHA25174 ANY CHA4146 ------------------------------------------------------------------------------------------------------------------------------------