6244( 8) - 11/21/95 08:54 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6244 Version: 8 Check-in Date: ********** 1.Proposal Title: HR 4796A: A Possible Protoplanet? ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Hot Stars GTO/HRS 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Michael Jura University of California, Los Angeles CoI: Andrea Ghez University of California, Los Angeles N ------------------------------------------------------------------------------------ 6. Abstract HR 4796A is a main sequence A-type star with more circumstellar dust than is located around Beta Pic. We propose to observe and classify HR 4796D, a close, faint, blue companion to HR 4796A. Is HR 4796D a background or foreground star, or is it physically associated with HR 4796A, perhaps a cloud of dust or a protoplanet? ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to use the FOS aboard HST to obtain a spectrum of the unidentified source HR 4796D using the FOS/RD detector with the G570H grating. The plan for target acquisition is to first acquire HR 4796A, a bright (mv = 5.8) nearby A0V star, using the FOS/BL detector with the G190H grating. After centering HR 4796A via a 4 stage Peak/up, an offset will be performed (sep = 4.9", PA = 315D) centering HR 4796D into the 0.5" aperature of the FOS/RD detector. A final PEAK/UP is performed to accurately center HR 4796D, and then the source is observed. The FOS exposure time is set by requiring a minimum SNR of 20, sufficient to identify normal stellar spectral features. Real Time Justification ----------------------- None Calibration Justification ------------------------- None Additional Comments ------------------- None ------------------------------------------------------------------------------------ 6244( 8) - 11/21/95 08:54 - [ 2] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6244( 8) - 11/21/95 08:54 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HR-4796A- STAR, A0-A3 V-IV RA=12H 36M 1.11S +/- 0.1S, DEC=- J2000 V=5.8 +/- 0.1 B-V=0.0 +/- 0.2 TYPE=A0V OFFSET 39D 52' 11.2" +/- 0.2" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.0034 -0.044 0.0 2 HR-4796D UNIDENTIFIED, Optical R = 4.9", PA = 315D, FROM 1 J2000 V=16.3 +/- 1 B-V=0.0 +/- 1.0 Emitter Comments: Measured R(Johnson) magnitude = 16.3, but V magnitude is uncertain Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 6244( 8) - 11/21/95 08:54 - [ 4] Visit: 01 Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HR-4796A- FOS/BL ACQ/PEA 4.3 G190H SCAN-STEP- 1 0.03S ONBOARD ACQuisition FOR 2 OFFSET K Y=1.204 SEARCH- SIZE-X=1 SEARCH -SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 2 HR-4796A- FOS/BL ACQ/PEA 1.0 G190H SCAN-STEP- 1 0.04S ONBOARD ACQuisition FOR 3 OFFSET K X=0.602 SCAN- STEP-Y=0.602 SEARCH-SIZE-X=6 SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 3 HR-4796A- FOS/BL ACQ/PEA 0.5 G190H SCAN-STEP- 1 0.04S ONBOARD ACQuisition FOR 4 OFFSET K X=0.30 SCAN- STEP-Y=0.30 SEARCH-SIZE-X=3 SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 4 HR-4796A- FOS/BL ACQ/PEA 0.3 G190H SCAN-STEP- 1 0.04S ONBOARD ACQuisition FOR 5 OFFSET K X=0.172 SCAN- STEP-Y=0.172 SEARCH-SIZE-X=3 SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 5 HR-4796D FOS/RD ACQ/PEA 0.3 G570H SEARCH-SIZE-X=5 1 12S ONBOARD ACQuisition FOR 6 K SEARCH-SIZE-Y=5 SCAN-STEP- X=0.17 SCAN- STEP-Y=0.17 ------------------------------------------------------------------------------------------------------------------------------------ 6 HR-4796D FOS/RD ACCUM 0.5 G570H 5700 1 300S END ORBIT EXPAND ------------------------------------------------------------------------------------------------------------------------------------ 6244( 8) - 11/21/95 08:54 - [ 5] Summary Form for Proposal 6244 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCAN-STEP-Y=1.204 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 SCAN-STEP-X=0.602 SCAN-STEP-Y=0.602 SEARCH-SIZE-X=6 SEARCH-SIZE-Y=2 SCAN-STEP-X=0.30 SCAN-STEP-Y=0.30 SEARCH-SIZE-X=3 SEARCH-SIZE-Y=3 SCAN-STEP-X=0.172 SCAN-STEP-Y=0.172 SEARCH-SIZE-X=3 SEARCH-SIZE-Y=3 SEARCH-SIZE-X=5 SEARCH-SIZE-Y=5 SCAN-STEP-X=0.17 SCAN-STEP-Y=0.17 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GTO/HRS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Hot Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQuisition FOR 2 ONBOARD ACQuisition FOR 3 ONBOARD ACQuisition FOR 4 ONBOARD ACQuisition FOR 5 ONBOARD ACQuisition FOR 6 END ORBIT EXPAND ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G190H G570H ------------------------------------------------------------------------------------------------------------------------------------ Target Names HR-4796A-OFFSET HR-4796D ------------------------------------------------------------------------------------------------------------------------------------