6064( 6) - 11/21/95 11:18 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6064 Version: 6 Check-in Date: ********** 1.Proposal Title: Companions to Tc-Deficient S and MS Stars ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Cool Stars GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Thomas B. Ake Computer Sciences Corporation CoI: Jeffery A. Brown University of Washington N CoI: Hollis R. Johnson Indiana University N ------------------------------------------------------------------------------------ 6. Abstract S and MS stars are peculiar red giant stars whose surface composition has been enriched in s-process elements and carbon. Most are thought to be asymptotic giant branch (AGB) stars that have undergone the third dredge-up. One subgroup of these, the objects without technetium, may instead be mass- transfer binaries where the abundance anomalies of the current red-giant primary may be due to accretion from the present secondary (a white dwarf) at an earlier epoch when the white dwarf was itself an AGB star. We propose to perform a survey of those objects whose previous IUE and He I Lambda10830 observations indicate that a hot source is definitely present. The HST data will allow us to distinguish between scenarios of enhanced far -UV photospheric emission from the red giant and hot white dwarf companions for these objects. ------------------------------------------------------------------------------------ 6064( 6) - 11/21/95 11:18 - [ 2] Observations Description ------------------------ The targets will be acquired using Side 2. Medium resolution exposures of Mg II will be taken in three pieces and coaligned to take out geomagnetic motions. Rapid read out exposures will be taken in low resolution from 1150-1575A. Real Time Justification ----------------------- The low dispersion exposures will have counts near the detector limit and thus should be scheduled when HST is between +/-25D geomagnetic latitude to reduce the overall background noise. These exposures also cover the O I 1304A region and the geocoronal contamination to the lines needs to be minimized. If the UV excess in these objects arises from the chromosphere of the red giant, the stellar O I will be an important diagnostic as to the level of chromospheric contribution. Calibration Justification ------------------------- None. Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6064( 6) - 11/21/95 11:18 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD191226 STAR,R N OR S TYPES RA = 20H 07M 26.50S +/- 0.01S, J2000 V=7.19 DEC = 36D 34' 2.9" +/- 0.1" B-V=1.80 Comments: Coordinates are from Hipparcos INCA Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.000 0.0 0.0 0.0 2 HD49368 STAR,R N OR S TYPES RA = 06H 48M 22.29S +/- 0.02S, 2000 V=7.30 +/- 0.41 DEC = 05D 32' 30.6" +/- 0.3", B-V=1.78 PLATE-ID = 03QX Comments: Coordinates are from GSC 6064( 6) - 11/21/95 11:18 - [ 4] Visit: 01 Visit Requirements: BETWEEN 25-JUL-95 AND 10-SEP-95 On Hold Comments: Additional Comments: The scheduling dates have been selected so that most of the rapid read out exposures are obtained during shadow. The DARK TIME special requirement would make these exposures unschedulable since it forces the entire exposure to be taken in shadow. The dates can be adjusted to maximize the shadow time for these exposures. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD191226 HRS ACQ 2.0 MIRROR-N2 1 15.75S ONBOARD ACQ FOR 20-40 Comments: STEP-TIME=1.75S; Expected count rate = 525 counts/sec ------------------------------------------------------------------------------------------------------------------------------------ 20 HD191226 HRS ACCUM 2.0 G270M 2811 3 490S ------------------------------------------------------------------------------------------------------------------------------------ 30 HD191226 HRS RAPID 2.0 G140L 1293 SAMPLE- 1 2626S TIME=0.35 Comments: Schedule between +/- 25D geomagnetic latitude and as much during shadow as possible to minimize background noise. This exposure should be adjusted to fill the entire orbit. ------------------------------------------------------------------------------------------------------------------------------------ 40 HD191226 HRS RAPID 2.0 G140L 1432 SAMPLE- 1 2626S TIME=0.35 Comments: Schedule between +/- 25D geomagnetic latitude and as much during shadow as possible to minimize background noise. This exposure should be adjusted to fill the entire orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6064( 6) - 11/21/95 11:18 - [ 5] Visit: 02 Visit Requirements: BETWEEN 13-JAN-96 and 19-FEB-96 On Hold Comments: Additional Comments: The scheduling dates have been selected so that most of the rapid read out exposures are obtained during shadow. The DARK TIME special requirement would make these exposures unschedulable since it forces the entire exposure to be taken in shadow. The dates can be adjusted to maximize the shadow time for these exposures. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 110 HD49368 HRS ACQ 2.0 MIRROR-N2 1 15.75S ONBOARD ACQ FOR 120-140 Comments: STEP-TIME=1.75S; Expected count rate = 495 counts/sec ------------------------------------------------------------------------------------------------------------------------------------ 120 HD49368 HRS ACCUM 2.0 G270M 2811 3 462.4S ------------------------------------------------------------------------------------------------------------------------------------ 130 HD49368 HRS RAPID 2.0 G140L 1293 SAMPLE- 1 2548S TIME=0.35 Comments: Schedule between +/- 25D geomagnetic latitude and as much during shadow as possible to minimize background noise. This exposure should be adjusted to fill the entire orbit. ------------------------------------------------------------------------------------------------------------------------------------ 140 HD49368 HRS RAPID 2.0 G140L 1432 SAMPLE- 1 2548S TIME=0.35 Comments: Schedule between +/- 25D geomagnetic latitude and as much during shadow as possible to minimize background noise. This exposure should be adjusted to fill the entire orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6064( 6) - 11/21/95 11:18 - [ 6] Summary Form for Proposal 6064 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM RAPID ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMPLE-TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Cool Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 25-JUL-95 AND 10-SEP-95 ONBOARD ACQ FOR 20-40 BETWEEN 13-JAN-96 and 19-FEB-96 ONBOARD ACQ FOR 120-140 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G270M G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD191226 HD49368 ------------------------------------------------------------------------------------------------------------------------------------