6767( 11) - 04/09/97 16:04 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6767 Version: 11 Check-in Date: 09-Apr-1997 15:54:19 1.Proposal Title: A Search for Brown Dwarfs and Luminous Young Planets in the Hyades ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle COOL STARS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: EDWARD ROSENTHAL HARVARD-SMITHSONIAN CFA CoI: Todd Henry Space Telescope Science Institute N CoI: Michael Skrutskie University of Massachusetts/Amherst N CoI: Iain Neill Reid California Institute of Technology N ------------------------------------------------------------------------------------ 6. Abstract We propose to continue a photometric search for very low- temperature (~ 1200 K) brown dwarfs and luminous, young planets as companions to 20 low-mass stars in the Hyades. The Planetary Camera will be used to obtain 1-Mum images of the primary stars in order to search for faint companions. We were awarded 8 stars for Cycle 5 in HST proposal GO-6137. The initial reduced data are presented here and answer the previous concerns of the Cool Stars Panel with respect to feasibility. We would now like to observe the remaining 12 stars from our original target list in order to obtain a more robust statistical sample. We are undertaking a complementary project at the NASA IRTF involving imaging at J (1.2 Mum), H (1.6 Mum), and K (2.2 Mum) for a sample of 75 low-mass Hyades stars, including these 20 HST stars. The IRTF search will be more sensitive, but will also have much poorer spatial resolution. Since a large fraction of stellar companions are within 10 AU of their primary (Henry 1991), and at the distance of the Hyades 0."1 ~ 5 AU, the guaranteed 0."1 spatial resolution of the PC is crucial for this project. Similar I-band Cycle 4-6 programs are also underway (e.g. SNAP- 5353/Reid), although aimed at detecting low-mass stellar companions in a larger sample. Our program will go deeper by 2 magnitudes, by using the 1-Mum (vs I-band) filter and by taking longer effective exposures. This push to fainter luminosities is substantial considering the large uncertainties associated with current brown dwarf models. ------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 2] Observations Description ------------------------ We propose a search for very low-mass companions (brown dwarfs/superplanets) to 12 low-mass M dwarfs in the Hyades cluster. We will image using the Planetary Camera (WFPC2/PC1) and the F1042M filter. Each target star will be imaged either 2 or 4 times in a single orbit; 12 target stars will thus require 12 orbits of HST observing time. This proposal is an extension of our Cycle 5 program GO-6137. For Cycle 5 we originally proposed for 20 target stars and were awarded 8 stars; all 8 of those stars have been observed in Cycle 5. The remaining 12 stars for which we are now proposing will complete our initial Hyades survey. The visibility period for the Hyades is 53 min; allowing 12 min for the guide star acquisition leaves 41 min on-source time per orbit. Based on experience with our Cycle 5 data thus far, we will likely take 2 1100-sec exposures per star, which should allow for adequate cosmic ray removal while not saturating on the primary star. If this procedure seems too risky (our Cycle 5 data are still being analyzed) then we will instead take 4 400-sec exposures per star, as we have already done with our first 6 Cycle 5 Hyades targets. These estimates assume that we continue to use SPATIAL SCANs (vs POS TARGs) for 4 exposures/orbit, which yield a reduced overhead of ~ 5 min total per read. Probably we will do 2 exposures/star. We will continue to sub-pixel dither if we choose 4 exposures/star, in order to improve photometric accuracy and spatial information, although for 2 exposures/star the added difficulty associated with cosmic ray removal indicates that integer-pixel dithering (in that case the primary aim is to avoid cosmetic defects on the chip) would be best. The final processed image frames will be corrected for cosmic rays, registered, and coadded. A model psf will be subtracted from the final images and the resulting final frame for each star will be compared with a Richardson- Lucy-Hook deconvolution in order to search for faint companions. Twenty target stars have been selected in total for this project because there are only ~ 20 RHY stars faint enough so as not to saturate the PC within our exposure times. While not a strict requirement, not saturating on the primary allows it to be used as a photometric check and also allows for companions to be detected as close to the primary as possible, considering the noise and Tiny Tim systematic modeling errors associated with the psf. Also, 20 total orbits keeps this observing program small while still providing a good statistical sample. If the Hyades brown dwarf distribution is similar to that of low-mass stellar companions to nearby field stars, then for 20 stars we would expect to detect ~ a few candidate substellar companions (Henry 1991). Each target star will require 1 orbit to complete its observations. These new observations will not only augment our existing Cycle 5 data but will also support the images of Reid's Cycle 4-6 SNAP programs. While the SNAP programs are geared to better determining what fraction of stars are binary with stellar companions, this proposal is aimed at imaging as deep and red as possible for a subset of the SNAP sample in order to search for brown dwarfs/superplanets. In addition, our F1042M filter overlaps with the shortest bandpass filter for NICMOS, allowing for a more direct comparison of our data with probable future NICMOS images. Real Time Justification ----------------------- None. Supporting HST observations have been obtained for the first 8 stars in our Hyades sample during Cycle 5 (GO-6137). Supporting ground-based observations have been obtained with the NASA IRTF, Mauna Kea, during 1994 and 1995. Additional ground-based infrared observations of Hyades stars are being carried out at the Keck telescope by MacIntosh and Zuckerman (MacIntosh, personal communication, 1995). The IRTF/Keck observations are in the near- infrared, at J (1.2 micron), H (1.6 micron), and K (2.2 micron). Because these images will be closer to the peak of the spectral energy distribution of very cool companions, they will go deeper than the HST observations proposed here, but with a trade-off of poorer spatial resolution. Since the majority of companions are expected to fall within ~ 0."25 at the distance of the Hyades (Henry 1991), the diffraction-limited spatial resolution of HST provides a critical additional measure of the Hyades low- mass binary fraction. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: ------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 RHY067 STAR, M V-IV RA=04H 07M 24.4S +/- 0.06S, J2000 V = 17.93 DEC=10D 44' 15" +/- 1.0" PLATE- I = 14.61 ID=01X0 Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1983.84 0.0000 0.0000 0.0220 2 RHY080 STAR, M V-IV RA=04H 09M 27.7S +/- 0.06S, J2000 V = 17.94 DEC=19D 18' 15" +/- 1.0" PLATE- I = 14.77 ID=000O Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 3 RHY083 STAR, M V-IV RA=04H 09M 57.0S +/- 0.06S, J2000 V = 17.44 DEC=16D 22' 42" +/- 1.0" PLATE- I = 13.94 ID=000O Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 4 RHY098 STAR, M V-IV RA=04H 12M 03.2S +/- 0.06S, J2000 V = 16.61 DEC=20D 49' 53" +/- 1.0" PLATE- I = 13.41 ID=000O Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 5 RHY110 STAR, M V-IV RA=04H 13M 54.0S +/- 0.06S, J2000 V = 16.78 DEC=15D 50' 09" +/- 1.0" PLATE- I = 13.75 ID=000O Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 6 RHY115 STAR, M V-IV RA=04H 14M 45.0S +/- 0.06S, J2000 V = 16.55 DEC=19D 03' 51" +/- 1.0" PLATE- I = 13.47 ID=000O Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 7 RHY126 STAR, M V-IV RA=04H 16M 13.4S +/- 0.06S, J2000 V = 17.35 DEC=16D 47' 48" +/- 1.0" PLATE- I = 13.88 ID=000O Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 8 RHY166 STAR, M V-IV RA=04H 21M 48.9S +/- 0.06S, J2000 V = 17.11 DEC=09D 50' 45" +/- 1.0" PLATE- I = 14.32 ID=002J Comments: from RHY sample 6767( 11) - 04/09/97 16:04 - [ 5] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.80 0.0000 0.0000 0.0220 9 RHY199 STAR, M V-IV RA=04H 24M 20.8S +/- 0.06S, J2000 V = 16.68 DEC=19D 10' 52" +/- 1.0" PLATE- I = 13.48 ID=000P Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 10 RHY202 STAR, M V-IV RA=04H 24M 30.5S +/- 0.06S, J2000 V = 16.68 DEC=18D 59' 14" +/- 1.0" PLATE- I = 13.35 ID=000P Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.96 0.0000 0.0000 0.0220 11 RHY254 STAR, M V-IV RA=04H 27M 51.75S +/- 0.06S, J2000 V = 16.34 DEC=09D 51' 18" +/- 1.0" PLATE- I = 13.33 ID=002J Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.80 0.0000 0.0000 0.0220 12 RHY297 STAR, M V-IV RA=04H 31M 12.5S +/- 0.06S, J2000 V = 17.09 DEC=12D 28' 38" +/- 1.0" PLATE- I = 13.86 ID=002J Comments: from RHY sample Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1982.80 0.0000 0.0000 0.0220 6767( 11) - 04/09/97 16:04 - [ 6] Visit: 01 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY067 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY067 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 7] Visit: 02 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY080 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY080 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 8] Visit: 03 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY083 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY083 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 9] Visit: 04 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY098 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY098 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 10] Visit: 05 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY110 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY110 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 11] Visit: 06 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY115 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY115 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 12] Visit: 07 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY126 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY126 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 13] Visit: 08 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY166 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY166 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 14] Visit: 09 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY199 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY199 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 15] Visit: 10 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY202 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY202 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 16] Visit: 11 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY254 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY254 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 17] Visit: 12 Visit Requirements: PCS MODE Fine ON HOLD On Hold Comments: PI Wishes to examine data from visit 2 Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 RHY297 WFPC2 IMAGE PC1 F1042M CR-SPLIT=NO 1 1100 S POS TARG 0, 0 SEQ 10-20 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 RHY297 WFPC2 IMAGE PC1 F953N CR-SPLIT=NO 1 1100 S POS TARG 0, 0.506 ------------------------------------------------------------------------------------------------------------------------------------ 6767( 11) - 04/09/97 16:04 - [ 18] Summary Form for Proposal 6767 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category COOL STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE Fine POS TARG 0, 0 SEQ 10-20 NON-INT POS TARG 0, 0.506 PCS MODE Fine ON HOLD ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F1042M F953N ------------------------------------------------------------------------------------------------------------------------------------ Target Names RHY067 RHY080 RHY083 RHY098 RHY110 RHY115 RHY126 RHY166 RHY199 RHY202 RHY254 RHY297 ------------------------------------------------------------------------------------------------------------------------------------