5869( 5) - 08/24/95 20:44 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5869 Version: 5 Check-in Date: ********** 1.Proposal Title: Chromospheric Activity in Quiet Stars: Halo Subdwarfs ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Cool Stars SNAP 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Ruth C. Peterson Astrophysical Advances CoI: Carolus Schrijver Lockheed N ------------------------------------------------------------------------------------ 6. Abstract All normal stars cool enough to have convection zones share a common level of chromospheric activity which decreases with advancing spectral type. Studies of indicators of low- temperature chromospheric activity in solar-type stars and K giants of near-solar metallicity, along with theoretical estimates of acoustic-wave heating, suggest strongly that this basal level of chromospheric activity is generated by acoustic waves; activity above this level is generated in conjunction with magnetic fields. Such a picture implies that even very old stars in this region of the HR diagram should show a minimum level of such activity. We propose to test this scenario with snapshot observations of Mg II in metal-poor solar-temperature field stars of the halo population, whose metallicities are 1/10 to 1/300 that of the Sun. No Ca II emission reversals have been detected in such stars to date. Because the magnesium abundance is more than a factor of ten higher than the calcium abundance, the Mg II lines may have large enough optical depth for the production of emission. More than a dozen targets are available which are bright enough for snapshot observations. This work may provide the first detections of chromospheric activity in such stars. If so, it will lend support to the idea of a basal level of chromospheric activity. ------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 2] Observations Description ------------------------ We may calculate the exposure level expected for one of the faint, metal-poor stars, HD 84937, from its IUE flux level (Wu Etal\ 1992). The continuum near the Mg II lines at 2800 Angstrom\ has a flux of 1.1 * 10^-12 cts/sec/cm^2/Angstrom. According to Table 8-2 of the GHRS Handbook v.\ 5.0, 46.7 counts/diode/s is expected for a flux of 10^-11 ergs/s/cm^2/Angstrom. Consequently we anticipate a count rate of 5.1 cts/diode/sec in the continuum. In three minutes = 180 sec, this amounts to a total of about 1000 counts in the continuum in each 9 kms\ diode. This exposure level should be adequate to detect an emission flux of about ten percent of the continuum above the line profile minimum. We request a guide-star acquisition for each object and a normal target acquisition in the LSA. Setup time is calculated as follows. Apparently no star requires a bright acquisition, in that Alpha Tau with V = 0.84 was acquired normally early in Cycle 4 (Handbook p.\ 69). Thus the setup time is 12 + 11 = 23 min. Overhead in ACCUM mode requires an additional 4 min. Time required exclusive of exposure time is then 27 min. We request 3min exposures for each target. Total spacecraft time will then be 30min for each object. Because of the potential interest to other areas of reasearch noted above, we are waiving the normal one-year proprietary period for the data to be obtained. The spectra may be made publicly available at the same time they are transmitted to us. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD219617 STAR,F3-F9 RA=23H 17M 5.03S +/- 0.1S, DEC=- J2000 V = 13 V=8.17 +/- 0.02 13D 51' 3.9" +/- 0.5" B-V=0.48 +/- 0.01 TYPE=F8 Comments: Binary - PA 48deg, sep 0.7", dmag=0.0 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0340 -1.192 0.0 2 HD84937 STAR,F3-F9 RA=9H 48M 56.09S +/- 0.1S, DEC= J2000 V = -20. V=8.30 +/- 0.05 +13D 44' 39.3" +/- 0.5" B-V=0.40 +/- 0.02 TYPE=F0 F-CONT(2800) = 11 +/- 3 E-13 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0.0255 -0.773 0.02 3 HD140283 STAR,F3-F9 RA=15H 43M 03.09S +/- 0.1S, DEC= J2000 V=7.22 +/- 0.05 -10D 56' 0.7" +/- 0.5" B-V=0.48 +/- 0.02 TYPE=F4 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0759 -0.302 0.0 4 HD106516 STAR,F3-F9 RA=12H 15M 10.56S +/- 0.1S, DEC= J2000 V = +9. V=6.11 +/- 0.02 -10D 18' 45.1" +/- 0.5" B-V=0.46 +/- 0.02 TYPE=F8 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0.0021 -1.018 0.0 5 HD19445 STAR,F3-F9 RA=3H 8M 25.52S +/- 0.1S, DEC= J2000 V = - V=8.05 +/- 0.05 +26D 19' 52.4" +/- 0.5" 140. B-V=0.46 +/- 0.02 TYPE=F4 Comments: Guide Star Cat coords: RA= 3H 8M 25.86 DEC= +26D 20' 5.8" PLATE-ID=00EJ Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0162 -0.843 0.0 6 HD114762 STAR,F3-F9 RA=+13H 12M 19.73S +/- 0.1S, J2000 V = V=7.31 +/- 0.02 DEC=+17D 31' 1.6" +/- 0.5" +49.5 B-V=0.53 +/- 0.02 TYPE=F8 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0410 -0.001 0.0 7 HD184499 STAR,G V-IV RA=19H 33M 27.08S +/- 0.1S, J2000 V = -163 V=6.63 +/- 0.02 DEC=+33D 12' 6.8" +/- 0.5" B-V=0.58 +/- 0.01 TYPE=G0 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0372 0.223 0.0 8 HD94028 STAR,F3-F9 RA=10H 51M 28.11S +/- 0.1S, J2000 V = +62. V=8.22 +/- 0.02 DEC=+20D 16' 39.0" +/- 0.5" B-V=0.47 +/- 0.01 TYPE=F5 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0188 -0.453 0.0 5869( 5) - 08/24/95 20:44 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 9 HD201891 STAR,F3-F9 RA=21H 11M 59.03S +/- 0.1S, J2000 V = -45 V=7.38 +/- 0.03 DEC=+17D 43' 39.7" +/- 0.5" B-V=0.51 +/- 0.02 TYPE=F5 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0085 -0.906 0.0 10 HD194598 STAR,F3-F9 RA=20H 26M 11.94S +/- 0.1S, J2000 V = -247 V=8.35 +/- 0.02 DEC=+9D 27' 0.4" +/- 0.5" B-V=0.48 +/- 0.01 TYPE=F5 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0.0083 -0.549 0.0 5869( 5) - 08/24/95 20:44 - [ 5] 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 HD219617 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2-3 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD219617 HRS IMAGE 2.0 MIRROR-N2 1 76.8S Comments: STEP-TIME=0.3S ------------------------------------------------------------------------------------------------------------------------------------ 3 HD219617 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 435.2S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 6] Visit: 02 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 HD84937 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD84937 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 7] Visit: 03 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 HD140283 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD140283 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 8] Visit: 04 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 HD106516 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD106516 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 9] Visit: 05 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 HD19445 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD19445 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 326.4S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 10] Visit: 06 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 HD114762 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD114762 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 11] Visit: 07 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 HD184499 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD184499 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 12] Visit: 08 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 HD94028 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD94028 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 13] Visit: 09 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 HD201891 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD201891 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 14] Visit: 10 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 HD194598 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD194598 HRS ACCUM 2.0 G270M 2800 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5869( 5) - 08/24/95 20:44 - [ 15] Summary Form for Proposal 5869 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ IMAGE ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FP-SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category SNAP ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Cool Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2-3 ONBOARD ACQ FOR 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G270M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD219617 HD84937 HD140283 HD106516 HD19445 HD114762 HD184499 HD94028 HD201891 HD194598 ------------------------------------------------------------------------------------------------------------------------------------