8111( 3) - 07/28/99 10:24 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8111 Version: 3 Check-in Date: 16-Feb-1999 15:34:01 1.Proposal Title: CS 22892--052: A Rosetta Star for the Age and Early History of the Galaxy ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Christopher Sneden University of Texas CoI: Prof. John Cowan University of Oklahoma N CoI: Prof. James Truran University of Chicago N CoI: Prof. Timothy Beers Michigan State University N ------------------------------------------------------------------------------------ 5. Abstract We propose to observe the ultra-metal-poor Galactic halo star CS 22892--052 and to produce the most complete abundance distribution of the heaviest stable elements, including platinum, osmium and lead, of any star outside of the Sun. These HST abundance data will then be used to estimate the initial abundance of the long-lived radioactive element thorium and, in comparison with its observed abundance, will be used to determine the age of this very old star. These studies, using radioactive chronometers in stars, provide an age estimate for the Galaxy independent of globular cluster and cosmological ages. Our proposed observations of CS 22892-- 052 will also provide significant new information about the early history of the Galaxy, specifically the nature of the earliest generations of stars and the types of nucleosynthetic processes that occurred in those stars. ------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 2] Observations Description ------------------------ We propose to obtain 57 orbits of integration on CS 22892- 052, and three orbits on HD 122563. The exposure times we employ adopt expected total overheads of 24 min for the first orbit (including guide star acquisition, target acquisition, peakup target acquisition, overheads -- 6 minutes each), and 11 min for all subsequent orbits (reacquisition time (5 min), overheads (6 min)), and a visibility time of 52 min per orbit. For 57 total orbits, this results in an net exposure time of 139, 440 sec. The expected S/N ratios have been calculated by comparison with previous HST observations of the metal-poor star HD 115444, a star with similar physical parameters to CS 22892-052. The physical parameters adopted for HD 115444 are Teff/logg/Fe/H = 4750/1.7/-2.8, while those for CS 22892-052 are 4760/1.3/-3.1. The metal abundance for CS 22892-052 is a factor of two lower than our comparison star, so the S/N estimates below are very conservative: we expect to obtain even higher S/N ratios than we are quoting (because of less UV line blanketing). We adopt previously measured HST fluxes for HD 115444 of 2.0times10^-13 (2900Angstrom) and 2.9times10^-13 (3060Angstrom) in the following calculations, reduce the expected flux for CS 22892-052 (V = 13.2) by the V magnitude difference with respect to HD 115444 (V = 8.9), and use the STIS ETC to obtain the following estimates of S/N. Because CS 22892-052 is quite faint, we expect that we may be forced to rebin our data (in some wavelength regions) by a factor of 2 or 4. Hence, in the table which follows, we quote expected S/N ratios using three assumptions -- full resolution/rebinned by 2/rebinned by 4. Note that as shown in the spectral synthesis figure attached to this proposal (see Fig. 2), we expect to be able to detect many of the lines of interest even with the maximum rebinning. We are requesting full resolution in the original data because we hope to detect additional weak lines which will require the highest resolution. This star has a surprising rich optical spectrum, so we do not wish to miss the opportunity of detecting weak lines from unanticipated species by observing at less than the full resolution of the STIS Echelle. The wavelengths chosen for expected S/N correspond to local peaks in the continuum in various intervals, and the S/N estimates quoted are per resolution element. begincenter begintabularcc multicolumn2cSignal-to-Noise Predictions , , multicolumn1cWavelength & multicolumn1cS/N , multicolumn1c(Angstrom) & multicolumn1c(Full/2/4) , 2900 & 29/40/56 , 2650 & 26/36/51 , 2450 & 9/12/17 , endtabular endcenter We would also like to comment that with the *2 rebinning, we have only reduced the resolution to a point where it is equivalent to the GHRS. We also wish to observe HD 122563 as a comparison source. This star is very bright and it has similar physical parameters to CS 22892-052 (Teff/logg/Fe/H = 4600/1.2/- 2.7). However, HD 122563 is deficient in neutron- capture element abundances, and lines of interest to us therefore will be weak- to-absent in this star; hence it is an excellent template to understand and compensate for atomic/molecular line contamination that will appear in the spectra of both stars. By comparison with previous HST observations of HD 122563, we estimate that we can obtain a VERY high S/N observation of HD 122563 in 3 orbits (52 min visibility per orbit). Since a number of the elements of greatest interest in CS 22892-052 are located at the blue extreme of our proposed spectrum, it is particularly important to have an essentially noise- free spectrum to compare with. The S/N estimates for HD 111563 at the same spectral locations as above are: begincenter begintabularcc multicolumn2cSignal -to- Noise Predictions , , multicolumn1cWavelength & multicolumn1cS/N , multicolumn1c(Angstrom) & multicolumn1c(Full/2/4) , 2900 & 155/219/308 , 2650 & 135/190/268 , 2450 & 60/85/119, endtabular endcenter Real Time Justification ----------------------- Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 3] Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD122563 Star, K III-I RA=14H 02M 31.96S +/- 0S, J2000 V = - V = 6.18 DEC=+09D 41' 10.6" +/- 0" 23.3 B-V = 0.85 U-B = 0.37 F(3000)=1.5e-12 Comments: coordinates are from the Hipparcos Catalgo Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.0128 -0.0701 0.00376 2 CS22892--052 Star, K III-I RA=22H 17M 01.67S +/- 0S, DEC=- J2000 V = - V = 13.18 16D 39' 26.7" +/- 0", PLATE-ID = 75.0 B-V = 0.78 03YO U-B = 0.14 8111( 3) - 07/28/99 10:24 - [ 5] Visit: 01 Visit Priority: 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 HD122563 STIS/C ACQ F28X50O MIRROR 1 .1 S ONBOARD ACQ FOR 2 CD II ------------------------------------------------------------------------------------------------------------------------------------ 2 HD122563 STIS/C ACQ/PEA 0.2X0.0 G430M 4194 1 1 S ONBOARD ACQ FOR 3-6 CD K 6FPA ------------------------------------------------------------------------------------------------------------------------------------ 3 HD122563 STIS/N ACCUM 0.2X0.0 E230M 2707 1 32.00 M UV-MAM 6FPA A ------------------------------------------------------------------------------------------------------------------------------------ 4 HD122563 STIS/N ACCUM 0.2X0.0 E230M 2707 1 49.00 M UV-MAM 6FPB A ------------------------------------------------------------------------------------------------------------------------------------ 5 HD122563 STIS/N ACCUM 0.2X0.0 E230M 2707 1 49.00 M UV-MAM 6FPC A ------------------------------------------------------------------------------------------------------------------------------------ 6 HD122563 STIS/N ACCUM 0.2X0.0 E230M 2707 1 49.00 M UV-MAM 6FPD A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 6] Visit: 02 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 7] Visit: 03 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 8] Visit: 04 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 9] Visit: 05 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 10] Visit: 06 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 11] Visit: 07 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 12] Visit: 08 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 13] Visit: 09 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 14] Visit: 10 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 15] Visit: 11 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 16] Visit: 12 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 17] Visit: 13 Visit Priority: 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 CS22892--05 STIS/C ACQ F28X50L MIRROR 1 .1 S ONBOARD ACQ FOR 2 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 CS22892--05 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 1 S ONBOARD ACQ FOR 3-4 2 CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 1 31 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 CS22892--05 STIS/N ACCUM 0.2X0.0 E230M 2707 4 49 M 2 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8111( 3) - 07/28/99 10:24 - [ 18] Summary Form for Proposal 8111 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50OII 0.2X0.06FPA 0.2X0.06FPB 0.2X0.06FPC 0.2X0.06FPD F28X50LP 0.2X0.06 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2 ONBOARD ACQ FOR 3-6 ONBOARD ACQ FOR 3-4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G430M E230M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD122563 CS22892--052 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 4194 2707 ------------------------------------------------------------------------------------------------------------------------------------