6641( 5) - 11/22/96 13:21 - [ 0] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6641 Version: 5 Check-in Date: 22-Nov-1996 13:14:55 1.Proposal Title: Continuation of Mass Ratio Determination for Doubles with Substellar Mass Members ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Cool Stars GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: LAURENCE TAFF THE JOHNS HOPKINS UNIVERSITY CoI: John Hershey Computer Sciences Corp (at Space Telescope N Science Institute) ------------------------------------------------------------------------------------ 6. Abstract Stellar masses which lie at or just below the stellar/sub- stellar boundary are difficult to determine with certainty. Only binary stars with low luminosity members provide these low masses. In the best studied cases a significant source of uncertainty in the estimated masses is the blending of the light on the photographic plates used to record the stars' positions. The blending must be modeled in order to determine the locus of the center of mass. The position of the center of mass determines the mass ratio. Without knowing this, or the fraction of the total mass of the pair present in each component of the system, the uncertainty resulting from blending provides a point of attack for those who question the reality of mass measurements as low as 0.06 Msun , and thus not clearly sub-stellar or ``brown dwarfs''. We have observed the separation of L722-22 in Cycle 3 and 4 of this proposal with sub-milliarcsecond internal precision, far below the error level of ground-based infrared speckle measurements. In a few years the relative orbit could be determined with milliarcsecond-level precision and the center of mass will be located for determination of the individual mass of each component. This is the third year of our original proposal. ------------------------------------------------------------------------------------ Observations Description ------------------------ We plan to continue as in Cycle 3 and 4, taking FGS TRANS mode scans of the double and POS mode observations of ? reference stars, with 3 visits of two orbits in a cycle. A ? POS mode observation of the double and a TRANS mode ? observation of a reference star will provide a check on the ? stability of the TRANS-POS mode offset for center-of-mass ? determination. All observations need to be done in fine-lock guidance. Real Time Justification ----------------------- ? No special scheduling requirements except the roughly even ? spacing of the 3 visits in the observing year. ? None. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6641( 5) - 11/22/96 13:21 - [ 1] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 L722-22 star, M V-IV RA= 3.8640416D +/-0.00139D, 2000 V = 12.62+/-0.5 DEC=-16.1307D +/-0.00139D Comments: SCIENTIFIC TARGET Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1983.8 0.04550 -0.5950 0.1890 2 L722-22-0002 star RA= 3.8676667D +/-0.00139D, 2000 V = 14.82+/-0.5 -REF DEC=-16.1415272D +/-0.00139D Comments: CLOSE REF STAR Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1983.8 0.0 0.0 0.0 3 L722-22-0003 star RA= 3.8372500D +/-0.00139D, 2000 V = 14.10+/-0.5 -REF DEC=-16.1202507D +/-0.00139D Comments: CLOSE REF STAR Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1983.8 0.0 0.0 0.0 6641( 5) - 11/22/96 13:21 - [ 2] Visit: 01 Visit Requirements: PCS MODE Fine BETWEEN 16-JUN-96 AND 07-JUL-96 On Hold Comments: Additional Comments: ONE OF A SERIES OF 6 VISITS SPREAD THROUGHOUT THE VISIBILITY SEASON. THE " BETWEEN " LIMITS OF THE VISITS ARE NOT ADJACENT. IF A VISIT IS SCHEDULED AT THE END OF ONE INTERVAL AND THE BEGINNING OF THE NEXT, THERE WILL BE AN INTERVAL ABOUT 3 WEEKS OF TIME BETWEEN THEM. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 L722-22 FGS POS 3 F583W 1 40 S SEQuence 1-8 NON-INTerruptible ------------------------------------------------------------------------------------------------------------------------------------ 2 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 3 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 4 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 5 L722-22 FGS TRANS 3 F583W step-size=1.0,scans=10 1 395 S ------------------------------------------------------------------------------------------------------------------------------------ 6 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 7 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 8 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 6641( 5) - 11/22/96 13:21 - [ 3] Visit: 02 Visit Requirements: PCS MODE Fine BETWEEN 28-JUL-96 AND 19-AUG-96 On Hold Comments: Additional Comments: ONE OF A SERIES OF VISITS SPREAD THROUGHOUT THE VISIBILITY SEASON Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 L722-22 FGS POS 3 F583W 1 40 S SEQuence 1-8 NON-INTerruptible ------------------------------------------------------------------------------------------------------------------------------------ 2 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 3 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 4 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 5 L722-22 FGS TRANS 3 F583W step-size=1.0,scans=10 1 395 S ------------------------------------------------------------------------------------------------------------------------------------ 6 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 7 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 8 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 6641( 5) - 11/22/96 13:21 - [ 4] Visit: 03 Visit Requirements: SCHED 90% PCS MODE Fine BETWEEN 1-NOV-97 AND 15-NOV-97 On Hold Comments: Additional Comments: ONE OF A SERIES OF VISITS SPREAD THROUGHOUT THE VISIBILITY SEASON Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 L722-22 FGS POS 3 F583W 1 40 S SEQuence 1-8 NON-INTerruptible ------------------------------------------------------------------------------------------------------------------------------------ 2 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 3 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 4 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 5 L722-22 FGS TRANS 3 F583W step-size=1.0,scans=10 1 395 S ------------------------------------------------------------------------------------------------------------------------------------ 6 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 7 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 8 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 6641( 5) - 11/22/96 13:21 - [ 5] Visit: 04 Visit Requirements: PCS MODE Fine BETWEEN 15-DEC-97 AND 31-DEC-97 On Hold Comments: Additional Comments: ONE OF A SERIES OF VISITS SPREAD THROUGHOUT THE VISIBILITY SEASON Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 L722-22 FGS POS 3 F583W 1 40 S SEQuence 1-8 NON-INTerruptible ------------------------------------------------------------------------------------------------------------------------------------ 2 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 3 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 4 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 5 L722-22 FGS TRANS 3 F583W step-size=1.0,scans=10 1 395 S ------------------------------------------------------------------------------------------------------------------------------------ 6 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 7 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 8 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 6641( 5) - 11/22/96 13:21 - [ 6] Visit: 05 Visit Requirements: PCS MODE Fine BETWEEN 10-DEC-96 AND 31-DEC-96 On Hold Comments: Additional Comments: ONE OF A SERIES OF VISITS SPREAD THROUGHOUT THE VISIBILITY SEASON Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 L722-22 FGS POS 3 F583W 1 40 S SEQuence 1-8 NON-INTerruptible ------------------------------------------------------------------------------------------------------------------------------------ 2 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 3 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 4 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 5 L722-22 FGS TRANS 3 F583W step-size=1.0,scans=10 1 395 S ------------------------------------------------------------------------------------------------------------------------------------ 6 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 7 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 8 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 6641( 5) - 11/22/96 13:21 - [ 7] Visit: 06 Visit Requirements: PCS MODE Fine BETWEEN 1-JUN-97 AND 30-JUN-97 On Hold Comments: Additional Comments: ONE OF A SERIES OF VISITS SPREAD THROUGHOUT THE VISIBILITY SEASON Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 L722-22 FGS POS 3 F583W 1 40 S SEQuence 1-8 NON-INTerruptible ------------------------------------------------------------------------------------------------------------------------------------ 2 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 3 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 4 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 5 L722-22 FGS TRANS 3 F583W step-size=1.0,scans=10 1 395 S ------------------------------------------------------------------------------------------------------------------------------------ 6 L722-22-000 FGS POS 3 F583W 1 120 S 3-REF ------------------------------------------------------------------------------------------------------------------------------------ 7 L722-22-000 FGS POS 3 F583W 1 120 S 2-REF ------------------------------------------------------------------------------------------------------------------------------------ 8 L722-22 FGS POS 3 F583W 1 90 S ------------------------------------------------------------------------------------------------------------------------------------ 6641( 5) - 11/22/96 13:21 - [ 8] Summary Form for Proposal 6641 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FGS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes POS TRANS ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters step-size=1.0 scans=10 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Cool Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE Fine BETWEEN 16-JUN-96 AND 07-JUL-96 SEQuence 1-8 NON-INTerruptible PCS MODE Fine BETWEEN 28-JUL-96 AND 19-AUG-96 SCHED 90% PCS MODE Fine BETWEEN 1-NOV-97 AND 15-NOV-97 PCS MODE Fine BETWEEN 15-DEC-97 AND 31-DEC-97 PCS MODE Fine BETWEEN 10-DEC-96 AND 31-DEC-96 PCS MODE Fine BETWEEN 1-JUN-97 AND 30-JUN-97 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F583W ------------------------------------------------------------------------------------------------------------------------------------ Target Names L722-22 L722-22-0002-REF L722-22-0003-REF ------------------------------------------------------------------------------------------------------------------------------------