10247( 2) - 05/11/04 10:29 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10247 Version: 2 Check-in Date: 11-May-2004 14:25:17 1.Proposal Title: Resolving a Binary System that Straddles the L/T Transition ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Ms. Kelle L. Cruz American Museum of Natural History CoI: Dr. I. Neill Reid Space Telescope Science Institute N CoI: Dr. Adam J. Burgasser University of California - Los Angeles N CoI: Dr. James Liebert University of Arizona N CoI: Dr. J. Davy Kirkpatrick California Institute of Technology N ------------------------------------------------------------------------------------ 6. Abstract We propose to make the first unequivocal resolved observation of a brown dwarf binary system comprised of an L dwarf and a T dwarf. The proposed observations will confirm the binarity of the system, measure the physical separation of the two components, provide a robust spectral type estimate for the T dwarf secondary, and enable the mass ratio of the system to be determined. As a late-L/mid-T binary, the components straddle the poorly understood "L/T transition" where a brightening of T dwarfs at J-band is observed compared to the comparatively warmer L dwarfs. In addition to testing theories for this brightening, these data will put strong constraints on substellar evolution and formation models. ------------------------------------------------------------------------------------ Observations Description ------------------------ We are using one orbit to confirm and study a likely brown dwarf binary system. Imaging with five NICMOS filters (F090M, F110W, F145M, F160W, and F170M) are used to confirm binarity and to estimate the spectral types of the components. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10247( 2) - 05/11/04 10:29 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 2M0518-28 STAR, BROWN DWARF RA=05H18M59.95S +/- 0.05", DEC=- J2000 J = 16.29 +/- 0.08 28D28'37.2" +/- 0.05" J-K=2.14+/-0.10 Coordinate Source: Other_Source: 2MASS 10247( 2) - 05/11/04 10:29 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type NIC-SPIRAL-DITH Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 1.304 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 0.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 10247( 2) - 05/11/04 10:29 - [ 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 2M0518-28 NIC1 MULTIAC NIC1 F090M SAMP-SEQ=STEP16,NSAMP=21 1 DEF PATTERN 1 1 CUM ------------------------------------------------------------------------------------------------------------------------------------ 2 2M0518-28 NIC1 MULTIAC NIC1 F110W SAMP-SEQ=STEP8,NSAMP=7 1 DEF PATTERN 1 2 CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 2M0518-28 NIC1 MULTIAC NIC1 F145M SAMP-SEQ=STEP8,NSAMP=15 1 DEF PATTERN 1 3 CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 2M0518-28 NIC1 MULTIAC NIC1 F160W SAMP-SEQ=STEP8,NSAMP=10 1 DEF PATTERN 1 4 CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 2M0518-28 NIC1 MULTIAC NIC1 F170M SAMP-SEQ=STEP8,NSAMP=18 1 DEF PATTERN 1 5 CUM ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 1 none none none 1 tbd 01 1 2 none none none 1 tbd 01 1 3 none none none 1 tbd 01 1 4 none none none 1 tbd 01 2 1 none none none 1 tbd 01 2 2 none none none 1 tbd 01 2 3 none none none 1 tbd 01 2 4 none none none 1 tbd 01 3 1 none none none 1 tbd 01 3 2 none none none 1 tbd 01 3 3 none none none 1 tbd 01 3 4 none none none 1 tbd 01 4 1 none none none 1 tbd 01 4 2 none none none 1 tbd 01 4 3 none none none 1 tbd 01 4 4 none none none 1 tbd 01 5 1 none none none 1 tbd 01 5 2 none none none 1 tbd 01 5 3 none none none 1 tbd 01 5 4 none none none 1 tbd 10247( 2) - 05/11/04 10:29 - [ 5] Summary Form for Proposal 10247 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMP-SEQ=STEP16 NSAMP=21 NSAMP=7 NSAMP=15 NSAMP=10 NSAMP=18 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1 PATTERN 1 2 PATTERN 1 3 PATTERN 1 4 PATTERN 1 5 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F090M F110W F145M F160W F170M ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2M0518-28 ------------------------------------------------------------------------------------------------------------------------------------