! File: 3479C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:09:13:58 coverpage: title_1: BORON IN POPULATION II DWARFS - PRIMEVAL OR SPALLATED? sci_cat: STELLAR ASTROPHYSICS sci_subcat: STELLAR ATMOSPHERES proposal_for: GO cont_id: 3479 pi_fname: BENGT pi_lname: EDVARDSSON pi_inst: UPPSALA ASTRONOMICAL OBSERVATORY pi_country: SWEDEN pi_phone: 46-18-512488 hours_pri: 19.91 num_pri: 2 hrs: Y off_fname: ERNST off_lname: VAN GRONINGEN off_title: DIRECTOR off_inst: UPPSALA ASTRONOMICAL OBSERVATORY off_addr_1: BOX 515 off_city: S-751 20 UPPSALA off_country: SWEDEN off_phone: (+46) 18 55 37 80 ! end of coverpage abstract: line_1: We propose to observe the B I 2496-97A lines with the GHRS in the line_2: echelle mode (SSA) in the spectra of 2 metal-poor, unevolved stars, in line_3: which beryllium has recently been found and with a new probable line_4: identification of boron in one of them. line_5: The goal is to find out whether Be and B in Pop. II dwarfs were line_6: synthesized in the Big Bang or by cosmic ray induced spallation in the line_7: early Galaxy, and in either case significantly constrain the line_8: multitudinous possibilities currently being debated in the literature. line_9: The programme will contribute significantly to the understanding line_10: of possible inhomogeneities induced by the quark to hadron phase line_11: transition in the Early Universe and of spallation processes and cosmic line_12: ray fluxes in the early Galaxy. ! ! end of abstract general_form_proposers: lname: EDVARDSSON fname: BENGT title: PI inst: UPPSALA ASTRONOMICAL OBSERVATORY country: SWEDEN esa: Y ! lname: GILMORE fname: GERARD inst: CAMBRIDGE, UNIVERSITY OF country: UNITED KINGDOM esa: Y ! lname: GUSTAFSSON fname: BENGT inst: UPPSALA ASTRONOMICAL OBSERVATORY country: SWEDEN esa: Y ! lname: JOHANSSON fname: SVENERIC inst: LUND, UNIVERSITY OF country: SWEDEN esa: Y ! lname: LAMBERT fname: DAVID mi: L inst: TEXAS, UNIVERSITY OF country: USA ! lname: NISSEN fname: POUL ERIK inst: AARHUS, UNIVERSITY OF country: DENMARK esa: Y ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: ! question: 3 section: 1 line_1: 2 Extreme Population II dwarfs will be observed line_2: using the HST GHRS in the high resolution mode (with R nominally being 100,000) line_3: and with the Small Science Aperture in the wavelength region 2490-2502 A, in line_4: order to explore and measure the B I lines at 2496.779 and 2497.725 A. line_5: Observations will be performed with central wavelength=2496 A, in FP-SPLIT mode line_7: with sub-exposures in different carrousel positions, in order to ascertain high line_8: S/N and minimize effects of glitches - note that vital results will be line_9: dependent on only two weak and blended spectral lines. To obtain S/N of about line_10: 50 at the full resolution of 100,000 we shall use STEP-PATT=7. line_11: Exact centering in the SSA is probably important for the highest possible S/N. line_12: We are of course interested in getting as small as possible overhead time and line_13: the longest possible spectrum exposure times. line_14: TARGET PRIORITIES: line_15: The priorities are 1) HD140281, 2) HD84937. If a continuum S/N of less than 40 line_16: is for some reason achieved for the first ACCUM spectrum (HD140283), then the line_17: time for HD84937 should instead be used for another spectrum of HD140283. line_18: In case this will cause the observation of HD84937 to be scheduled 3 months line_19: later than those of HD140283 we will accept that penalty. ! question: 3 section: 2 line_1: POSITIONS: line_2: The positions and proper motions are from the Carlsberg Automatic Meridian line_3: Circle Catalogues No 4 and 5, and agrees very well with PPM positions. line_4: Since the right ascension of HD140283 differs by 3.0 arc-seconds from the SAO line_5: catalogue value (when both are precessed to the Equinox J2000 and Epoch 1992.5) line_6: we have decided to use a search size of 5. line_7: CENTRAL WAVELENGTHS: line_8: The best BI line has a lab. wavelength of 2496.779 A. From Fig 4.16 in the GHRS line_9: instrument handbook the least granulated part of the diode array is at diode line_10: positions 265 to 290, so that line should land near diode 277. Assuming that a line_11: higher diode position value corresponds to a longer wavelength and that the line_12: central wavelength falls at diode position 250 the central wavelength should be line_13: about 27 diodes times 0.023 A = 0.62 A bluewards of the actual line wavelength, line_14: that is at 2496.15 A. (We assume order No m=23, and mlambda about 57500) line_15: The radial velocity of HD140283 is -171 km/s corresponding to a blueshift of line_16: 1.425 A: the central wavelength should thus be 2494.7 A. line_17: The radial velocity of HD84937 is -19 km/s corresponding to a blueshift of line_18: 0.16 A: the central wavelength should thus be 2496.0 A. line_19: Since BRIGHT=RETURN is not yet available for SSA ACQ/Peakup, BRIGHT and line_20: FAINT limits have been added for those. For HD140283 the count rates from line_21: Duncan et al GO observations at this wavelength may be used to check. line_22: HD84937 is very likely to be 70 percent as bright as HD140283 at 2500 A. ! question: 3 section: 3 line_1: EXPOSURE TIMES: line_2: Since exposure times between 5 and 10 minutes are recommended to avoid GIMP we line_3: have selected an exposure time of 336 seconds. This is an even multiple (60) line_4: of STEP-PATT * FP-SPLIT * STEP-TIME which is 7 * 4 * 0.2 = 5.6 seconds. line_5: The default STEP-TIME of 0.2 seconds was adopted. line_6: SPECTRUM-Y-BALANCE: line_7: In the GHRS Instrument Handbook, Sect. 3.3.2.1 The possibility of a line_8: SPECTRUM-Y-BALANCE is mentioned. Since this is not mentioned among the HRS line_9: ACCUM Instrument Parameters, we have assumed below that this is line_10: performed by default before long exposures like these. line_11: CALIBRATION SPECTRA line_12: We assume that standard calibration spectra will be useful for the spectrum line_13: reductions, if a higher quality as regards spectral resolution or S/N would line_14: be achieved with special calibration exposures we would be interested in line_15: using some spacecraft time for such. line_16: Exact ABSOLUTE wavelength calibration is not important, and not worth extra line_17: spacecraft time. ! question: 4 section: 1 line_1: No other possibility but vacuum-ultraviolet spectroscopy at high resolution line_2: exists for measuring Boron abundances in Pop. II dwarfs. Previous attempts with line_3: IUE prove the resolution and S/N achievable for these apparently rather faint line_4: stars to be too low. line_5: The project is founded on observations with large Earth-based telescopes line_6: (the AAT and the WHT) in the near ultraviolet spectrum of Be. Further line_7: complementary observations in the 3130 A region will be made to reduce the line_8: errors in the Be results further. ! question: 5 section: 1 line_1: In order to ascertain a S/N ratio of at least 40 for our highest priority line_2: target HD140283 we request that this star is observed first (lines 1-3) and line_3: that we then get the possibility to examine the resulting S/N, before deciding line_4: whether to use the rest of our time for the second priority star HD84937 line_5: (lines 4-6) or to use it for another spectrum of HD140283 (lines 14-16). ! question: 6 section: 1 line_1: None. ! question: 7 section: 1 line_1: The spectra will be reduced using STSDAS software, with facilities at line_2: ST-ECF and at Cambridge, Uppsala and Aarhus Universities. line_3: We expect to be able to make the synthetic spectrum analysis with a pretty line_4: complete line list. The wavelength region will be scrutinized in high-resolution line_5: laboratory spectra for ascertaining identifications and estimating branching line_6: ratios and hyperfine structure at the Physics Institute of the Lund University. line_7: The analysis of the spectra will be carried out at Uppsala using Uppsala line_8: model atmospheres and detailed synthetic spectra at the highest standard line_9: possible to achieve. Effects of departures from LTE and inhomogeneities in the line_10: atmospheres will be explored. Complementary observations will be made with the line_11: Anglo-Australian Telescope and the William Herschel Telescope. 10 and 4 nights line_12: respectively, have been given to our project at these telescopes - 4 nights at line_13: the AAT have already been used, another 6 are granted in September 1991, and 4 line_14: nights at WHT in June 1992. This will guarantee that very line_15: accurate Be abundances will have been derived for our programme stars in early line_16: spring 1992, as well as for a number of other Pop. II stars. line_17: PEN has recently obtained spectra, at R~30,000 and S/N~100, at the ESO 3.6m line_18: telescope in the wavelength region 5000-6000 A for our programme stars. These line_19: will be analyzed in September this year, yielding more accurate determinations line_20: of the abundances of iron, calcium and magnesium, and hopefully safer values of line_21: the surface gravity parameters; all leading to higher accuracy in our analysis line_22: of the HST GHRS spectra. ! question: 8 section: 1 line_1: None. ! question: 9 section: 1 line_1: a. HST program numbers and titles, and specification whether they are related line_2: to this project or not: line_4: GG: line_5: K2684 participates in the Medium Deep Survey Key Project, with 200 hours of line_6: time allocated in Cycle 1, not related line_8: DLL: line_9: GTO1063, "The extended atmosphere of Betelgeuse", not related line_10: GTO1064, "Boron in Main Sequence stars", related to this project: line_11: DLL has received GTO time in cycle 0 for the study of boron in three line_12: metal poor dwarfs (HD 140283, 19445, 201891) and in three disk F dwarfs line_13: (Procyon, iota Peg, theta Uma). line_14: GTO1065, "Isotopic abundances of carbon and oxygen and fractionation in line_15: interstellar carbon monoxide", not related line_16: GTO1066, "Carbon chemistry in interstellar diffuse clouds - the C2 molecule", line_17: not related line_18: GTO1067, "Old novae and cataclysmic variables - DQ Her and G61-29", not related line_19: GTO1068, "Epsilon Aurigae - A search for the secondary", not related line_20: GTO1069, "Interstellar boron and the boron isotopic ratio", not related since it ! question: 9 section: 2 line_1: concerns boron in the Galaxy today. line_3: BG + PEN: line_4: GTO1258, "Chemical evolution and history of star formation in the LMC", line_5: not related line_7: b. Summary of main results obtained from previous related programs: line_9: Observations of two of the three stars in project GTO1064 have already been line_10: obtained, and preliminary results are at hand: For HD 140283 an upper limit line_11: (marginally a detection) of the boron abundance, log(B/H)=-12.1, is found. For line_12: HD 201891 a much larger upper limit is suggested. A paper on B in Pop. II stars line_13: is in preparation. line_15: c. No publications. ! question: 10 section: 1 line_1: Adequate computer resources and personnel are available at all line_2: participating institutes. STSDAS and IRAF are available at Cambridge University line_3: and will be installed at Aarhus University and at Uppsala. line_4: Programs for model atmospheres and synthetic spectrum analyses are line_5: developed and running at Uppsala. ! !end of general form text general_form_address: lname: EDVARDSSON fname: BENGT category: PI inst: UPPSALA ASTRONOMICAL OBSERVATORY addr_1: BOX 515 city: S-751 20 UPPSALA country: SWEDEN phone: (+46) 18 51 24 88 telex: 76024 UNIVUPS S ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: HD140283 name_2: BD-10D4149 descr_1: A,133 pos_1: RA = 15H 43M 3.983S +/- 0.02S, pos_2: DEC = -10D 55' 57.13" +/- 0.3" equinox: J2000 pm_or_par: Y pos_epoch_bj: J pos_epoch_yr: 1988.38 ra_pm_val: -0.075600 ra_pm_unct: 0.001333 dec_pm_val: -0.3010 dec_pm_unct: 0.0200 an_prlx_val: 0.0300 an_prlx_unct: 0.0200 rv_or_z: V=-171 fluxnum_1: 1 fluxval_1: V = 7.23, TYPE = F3 VI fluxnum_2: 2 fluxval_2: B-V = 0.49 +/- 0.02 fluxnum_3: 3 fluxval_3: U-B = 0.20 +/-0.02 fluxnum_4: 4 fluxval_4: F(2500) = 1.1 +/- 0.3 E-12 ! targnum: 2 name_1: HD84937 name_2: GSC0834-00654 name_3: BD+14D2151 descr_1: A,133 pos_1: RA = 9H 48M 55.742S +/- 0.02S, pos_2: DEC = 13D 44' 50.03" +/- 0.3" equinox: J2000 pm_or_par: Y pos_epoch_bj: J pos_epoch_yr: 1986.09 ra_pm_val: 0.025733 ra_pm_unct: 0.000200 dec_pm_val: -0.7730 dec_pm_unct: 0.0010 an_prlx_val: 0.1000 an_prlx_unct: 0.0500 rv_or_z: V=-19 fluxnum_1: 1 fluxval_1: V = 8.33, TYPE = F0 VI fluxnum_2: 2 fluxval_2: B-V = 0.37 +/- 0.02 fluxnum_3: 3 fluxval_3: U-B = -0.20 +/- 0.03 fluxnum_4: 4 fluxval_4: F(2500) = 0.79 +/- 0.2 E-12 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: HD140283 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 5S fluxnum_1: 4 priority: 1 param_1: SEARCH-SIZE=5 param_2: FAINT=8000 param_3: BRIGHT=65535 req_1: ONBOARD ACQ FOR 2-3; req_2: CYCLE 2 comment_1: THE STAR WAS OBSERVED IN CYCLE 1 comment_2: BY D.DUNCAN AND COLLEAGUES (GTO). comment_3: (GHRS, LSA, WAVEL.=2500) comment_4: STEP-TIME=0.2S ASSUMED ! linenum: 2.000 targname: HD140283 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 20.4S fluxnum_1: 4 priority: 1 req_1: ONBOARD ACQ FOR 3; req_2: CYCLE 2 ! linenum: 3.000 targname: HD140283 config: HRS opmode: ACCUM aperture: 0.25 sp_element: ECH-B wavelength: 2494.7 num_exp: 65 time_per_exp: 336S s_to_n: 50 s_to_n_time: 21840S fluxnum_1: 4 priority: 1 param_1: FP-SPLIT=STD param_2: STEP-PATT=7 req_1: CYCLE 2; comment_1: COMB-ADDITION=4 DEFAULT ! linenum: 4.000 targname: HD84937 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 5S fluxnum_1: 4 priority: 2 param_1: SEARCH-SIZE=5 param_2: FAINT=5600 param_3: BRIGHT=65535 req_1: ONBOARD ACQ FOR 5-6; req_2: CYCLE 2; req_3: COND IF HD140283 SNR > 40 / 4-6; req_4: SELECT 1 OF 4-6 OR 14-16 comment_1: STEP-TIME=0.2S ASSUMED ! linenum: 5.000 targname: HD84937 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 20.4S fluxnum_1: 4 priority: 2 req_1: ONBOARD ACQ FOR 6; req_2: CYCLE 2 ! linenum: 6.000 targname: HD84937 config: HRS opmode: ACCUM aperture: 0.25 sp_element: ECH-B wavelength: 2496.0 num_exp: 87 time_per_exp: 336S s_to_n: 55 s_to_n_time: 29232S fluxnum_1: 4 priority: 2 param_1: FP-SPLIT=STD param_2: STEP-PATT=7 req_1: CYCLE 2 comment_1: COMB-ADDITION=4 DEFAULT comment_2: STEP-TIME=0.2 DEFAULT ! linenum: 14.000 targname: HD140283 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 5S fluxnum_1: 4 priority: 2 param_1: SEARCH-SIZE=5 param_2: FAINT=8000 param_3: BRIGHT=65535 req_1: ONBOARD ACQ FOR 15-16; req_2: CYCLE 2; req_3: COND IF HD140283 SNR < 40 / 14-16 comment_1: STEP-TIME=0.2S ASSUMED comment_2: FAINT MAY NEED ADJUSTING ! linenum: 15.000 targname: HD140283 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 20.4S fluxnum_1: 4 priority: 2 req_1: ONBOARD ACQ FOR 16; req_2: CYCLE 2 ! linenum: 16.000 targname: HD140283 config: HRS opmode: ACCUM aperture: 0.25 sp_element: ECH-B wavelength: 2494.7 num_exp: 87 time_per_exp: 336S s_to_n: 65 s_to_n_time: 29232S fluxnum_1: 4 priority: 2 param_1: FP-SPLIT=STD param_2: STEP-PATT=7 req_1: CYCLE 2 comment_1: COMB-ADDITION=4 DEFAULT ! ! end of exposure logsheet ! No scan data records found