10511( 3) - 09/22/05 15:47 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10511 Version: 3 Check-in Time: 22-Sep-2005 19:47:06 Title An Edge-on Disk around a Brown Dwarf? ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 14 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Kevin Luhman Smithsonian Institution Astrophysical Observatory CoI: Dr. Paola D'Alessio Universidad Nacional Autonoma de Mexico N (UNAM) ------------------------------------------------------------------------------------ Abstract We have recently discovered a young brown dwarf in the Taurus star-forming region that exhibits several characteristics (very faint for its spectral type, forbidden emission lines, anomalous near-IR colors) that are often observed in stars occulted by edge-on circumstellar disks. We propose to determine if an edge-on disk is indeed present by obtaining high-resolution images of this brown dwarf with ACS/HRC on HST. If the disk is detected, we will constrain its physical properties, particularly its diameter, by fitting the images with the predictions of our models of brown dwarfs occulted by circumstellar disks. These observations could potentially provide the first direct measurement of the size of a disk around a brown dwarf, which would comprise a fundamental test of models for the formation of these objects (e.g., embryo ejection). ------------------------------------------------------------------------------------ 10511( 3) - 09/22/05 15:47 - [ 2] Observations Description ------------------------ We will use the PC to obtain images of a nearly point-like target (unresolved at 1") in the F675W, F791W, F850LP, and F631N filters. In each filter, we will obtain two images. The total exposure times will be 320, 320, 320, and 600 sec. All of these observations will be completed in one orbit in one visit. There are no scheduling constraints. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10511( 3) - 09/22/05 15:47 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 2MASS0438148 STAR, BROWN DWARF RA=04H38M14.8610S +/- 0.1", J2000 V = 23.0+/-0.5 6+261139 DEC=+26D11'39.94" +/- 0.1", I=17.8 PLATE-ID=000L Coordinate Source: IMAGE_TIED_TO_GSC_FRAME 10511( 3) - 09/22/05 15:47 - [ 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 2MASS043814 WFPC2 IMAGE PC1 F675W 2 160 S 86+261139 ------------------------------------------------------------------------------------------------------------------------------------ 2 2MASS043814 WFPC2 IMAGE PC1 F791W 2 160 S 86+261139 ------------------------------------------------------------------------------------------------------------------------------------ 3 2MASS043814 WFPC2 IMAGE PC1 F850LP 2 160 S 86+261139 ------------------------------------------------------------------------------------------------------------------------------------ 4 2MASS043814 WFPC2 IMAGE PC1 F631N 2 300 S 86+261139 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2MASS04381486+2611 1 WFPC2 IMAGE PC1 F675W none none 1 none 1 N/A 39 2MASS04381486+2611 1 WFPC2 IMAGE PC1 F675W none none 2 none 1 N/A 39 2MASS04381486+2611 2 WFPC2 IMAGE PC1 F791W none none 1 none 1 N/A 39 2MASS04381486+2611 2 WFPC2 IMAGE PC1 F791W none none 2 none 1 N/A 39 2MASS04381486+2611 3 WFPC2 IMAGE PC1 F850LP none none 1 none 1 N/A 39 2MASS04381486+2611 3 WFPC2 IMAGE PC1 F850LP none none 2 none 1 N/A 39 2MASS04381486+2611 4 WFPC2 IMAGE PC1 F631N none none 1 none 1 N/A 39 2MASS04381486+2611 4 WFPC2 IMAGE PC1 F631N none none 2 none 1 N/A 39 10511( 3) - 09/22/05 15:47 - [ 5] Summary Form for Proposal 10511 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F675W F791W F850LP F631N ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2MASS04381486+261139 ------------------------------------------------------------------------------------------------------------------------------------