5859( 5) - 08/01/95 15:16 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5859 Version: 5 Check-in Date: ********** 1.Proposal Title: Major NLTE Corrections to HST Boron Observations? ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Cool Stars GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Douglas Duncan University of Chicago CoI: Dan Kiselman Nordita // Blegdamsvej 17 // DK-2100 N Copenhagen 0 CoI: Julie Thorburn Yerkes Observatory // Williams Bay, WI N 53191 ------------------------------------------------------------------------------------ 6. Abstract A theoretical study of NLTE effects in the analysis of HST boron observations indicates that all currently-reported abundances are wrong by factors of 2.5-4X. (A systematic effect much larger than any measurement error). If true, this would force major changes in the modelling of Be and B abundances as products of cosmic ray spallation plus direct production by supernovae in the early galaxy. It would help explain why no simple model of galactic chemical evolution can yet explain the evolution of the light elements Li, Be, and B at the same time as the evolution of heavier elements such as Fe and O. We can test the NLTE prediction by observing the BII line at 1362 Angstrom in the star Procyon, whose BI abundance has been extremely well determined from two groups previous HST observations of the BI 2500Angstrom line. (The repaired GHRS opens the possibility of observing the BII line). Our calculations (see figures) demonstrate we should easily see if large amounts of B are being "hidden" (from BI observations) by being in the form of BII. We will use the star Sirius as a reference for differential analysis. BII was observed in Vega and Sirius by the Copernicus satellite 20 years ago, and our re-analysis of this data (see figure) shows we have an excellent chance of success in the present proposal. ------------------------------------------------------------------------------------ 5859( 5) - 08/01/95 15:16 - [ 2] Observations Description ------------------------ Two objects will be observed: Procyon, the primary target, and Sirius, the standard. For each, a single visit will be used to obtain FP-SPLIT observations at the single wavelength 1362Angstrom. Sirius will be observed with echelle-A and G140M, and Procyon with GHRS G140M exposure. (Even a star as bright as Procyon is not bright at 1300Angstroms. Sirius is hotter, that is why it is much brighter at these wavelengths. Exposure times of 8 min (Sirius) and 160 min (Procyon; 3 orbits) are required to achieve S/N of 300 and 80 respectively. The UV fluxes of both stars at 1360Angstrom are well known, so the exposure times are quite precise. We extracted specra from the IUE archives to check each star. Real Time Justification ----------------------- None. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5859( 5) - 08/01/95 15:16 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD61421 STAR,F3-F9 RA=7H 39M 18.113S +/- 0.1S, DEC= J2000 V=0.38 +/- 0.02 5D 13'30.1" +/- 0.5" B-V=0.42 +/- .02 TYPE=F5 IV-V F-CONT(1360) = 1.3 +/- 1.0 E-12 F-CONT(2090) = 3.5 +/- 1.0 E-10 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.04755 -1.023 .292 2 HD48915 STAR,A0-A3 V-IV RA=6H 45M 8.871S +/- 0.1S, DEC= J2000 V=-1.46 +/- 0.02 -16D 42'58.0" +/- 0.5" B-V=0.0 +/- .02 TYPE=A1V F-CONT(1360) = 3.8 +/- 1.0 E-9 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 -0.0385 -1.205 .378 5859( 5) - 08/01/95 15:16 - [ 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 HD61421 HRS ACQ 2.0 MIRROR-N1 1 1.8S ONBOARD ACQ FOR 2-3 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD61421 HRS ACCUM 2.0 G140M 1362 FP-SPLIT=STD 1 1491S ------------------------------------------------------------------------------------------------------------------------------------ 3 HD61421 HRS ACCUM 2.0 G140M 1362 FP-SPLIT=STD 6 1347S ------------------------------------------------------------------------------------------------------------------------------------ 5859( 5) - 08/01/95 15:16 - [ 5] 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 HD48915 HRS ACQ 2.0 MIRROR-A1 1 1.8S ONBOARD ACQ FOR 2-3 Comments: STEP-TIME=0.2S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD48915 HRS ACCUM 2.0 ECH-A 1362 FP-SPLIT=STD 1 544S ------------------------------------------------------------------------------------------------------------------------------------ 3 HD48915 HRS ACCUM 2.0 G140M 1362 FP-SPLIT=STD 1 217.6S ------------------------------------------------------------------------------------------------------------------------------------ 5859( 5) - 08/01/95 15:16 - [ 6] Summary Form for Proposal 5859 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FP-SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Cool Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2-3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N1 G140M MIRROR-A1 ECH-A ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD61421 HD48915 ------------------------------------------------------------------------------------------------------------------------------------