! $Id: 5319,v 4.1 1994/07/27 16:32:57 pepsa Exp $ coverpage: title_1: THE SULFUR AND IRON ABUNDANCE OF THE PECULIAR SDO STAR FEIGE 46: title_2: A CRUCIAL TEST OF THE DUST FRACTIONATION HYPOTHESIS CYC4 - MEDIUM sci_cat: HOT STARS sci_subcat: LATE EVOLUTION proposal_for: GO pi_fname: ULRICH pi_lname: HEBER pi_inst: 5578 pi_country: GERMANY pi_phone: +49 951 9522214 hours_pri: 4.58 num_pri: 1 hrs: Y off_fname: IRMELA off_lname: BUES off_title: PROFESSOR off_inst: 5578 off_addr_1: DR. REMEIS-STERNWARTE, ASTRONOMISCHES INSTITUT off_addr_2: DER UNIVERSITAET ERLANGEN-NUERNBERG off_city: D 96049 BAMBERG off_country: GERMANY off_phone: +49 951 9522213 ! end of coverpage abstract: line_1: Feige 46 is a helium rich, subluminous O star that displays a very line_2: peculiar abundance pattern dissimilar to all other sdO stars analysed line_3: so far. C and N are almost solar whereas Mg and Si are deficient by line_4: a factor of 7 and 50, respectively. Its abundance pattern bears strong line_5: resemblence to that found in peculiar post-AGB F stars. Their line_6: depletion pattern are qualitatively similar to that found in the line_7: interstellar medium and therefore dust fractionation has been proposed line_8: as the origin of these pecularities. The same mechanism was recently line_9: suggested to explain the C/Si anticorrelation and the Si/Fe correlation line_10: found in normal A and Lambda Boo stars. This proposals sets out to test line_11: whether the dust fractionation mechanism can explain the abundance line_12: pattern of Feige 46. The measurement of the abundance of a volatile line_13: element such as Ar, S or Zn is necessary. For Feige 46 only S is line_14: accessible to a NLTE analysis at present via its strongest UV line at line_15: 1501.8 Angstroem. In addition the Fe/Si ratio shall be derived from line_16: UV spectra to check whether the A star correlation is also valid line_17: for Feige 46. Existing IUE spectra are of insufficient quality and the line_18: GHRS is required to obtain suitable data. If proven Feige 46 would be line_19: the first highly-evolved O-type star whose surface composition is line_20: governed by the separation of gas and dust. ! ! end of abstract general_form_proposers: lname: HEBER fname: ULRICH title: PI inst: 5578 country: GERMANY ! lname: DREIZLER fname: STEFAN inst: 5578 country: GERMANY esa: Y ! lname: RAUCH fname: THOMAS inst: 5584 country: GERMANY esa: Y ! lname: WERNER fname: KLAUS inst: 5584 country: GERMANY esa: Y ! lname: BUTLER fname: KEITH inst: 5588 country: GERMANY esa: Y ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: The GHRS equipped with the G160M grating shall be used to obtain line_2: UV spectral of the following four wavelength regions: line_4: i) 1485-1518 Angstroem to measure the crucial sulfur line , SV 1501.8 A line_5: ii) 1440-1473 Angstroem to measure the iron lines plotted in Fig. 4 line_6: iii) 1380-1413 Angstroem to measure the resonance doublet Si IV, 1392,1402A line_7: iv) 1325-1358 Angstroem to measure the OIV multiplet UV17 at 1338.6, 1343.0 line_8: and 1343.5A line_10: In order to measure well defined line prifiles a S/N of 40 per resolution line_11: element is aimed at. ! question: 4 section: 1 line_1: High resolution optical spectra of Feige 46 have been obtained with the line_2: ESO CASPEC spectrograph at the 3.6m telescope and were analysed by means line_3: of Non-LTE model atmospheres techniques. line_4: Ultraviolet spectroscopy of Feige 46 has been carried out with line_5: the IUE satellite. The star has been observed in the low resolution line_6: mode (about 0.5nm). These spectra of too low spectral resolution and too line_7: small S/N for the proposed investigation. Feige 46 has in addition been line_8: observed in the high resolution mode. However, the spectrum is very noisy and line_9: cannot be used to measure line profiles because the star is faint line_10: (V=13.3mag), see also Fig.3. ! ! question: 9 section: 1 line_1: ID 2741: A FOS spectrum with the blue detector, grating G130H and the 0.25"*1.4" line_2: aperture has been obtained on May 8, 1992. It has been analysed by comparing line_3: the normalized spectrum to synthetic spectra calculated From our NLTE model line_4: grid. The effective temperature has been determined with unprecedented line_5: accuracy (better than 3%) to be 140,000K). This fully confirmed the result of a line_6: previous optical nalysis and showed that systematic errors in that analysis are line_7: non-existent. Determination of C,N and O abundances is in progress. Due to line_8: better known Teff and the larger number of spectral lines the analysis will line_9: give much more reliable abundances that the early results based on optical line_10: spectroscopy. line_11: ID 3513: The observations have been carried out in May 1993 line_12: ID 4263: Observations are presently scheduled for December 93 and Januar 94. line_13: Archival FOS spectra: The hot DO star KPD0005+5106 has been analysed from line_14: HST-FOS spectra collected from the archive and using the same NLTE model line_15: atmosphere techniques as for PG1159-035 and proposed here for Feige 46. The line_16: photospheric parameters (Teff=120000K, log g=7) are derived from the He II line_17: lines in the UV and demonstrate that KPD0005+5106 is the hottest DO star known line_18: today. C and N abundance was also determined from the FOS spectra. KPD0005+5106 line_19: is of particular interest, since it is the first white dwarf to show ultra-high line_20: ionisation emission features (OVIII) in the optical and HST-FOS spectra. ROSAT line_21: observations shall help to identify the origin of the ultrahigh-ionisation line_22: lines. A prerequiste for such an investigation, however, is the precise line_23: knowledge of the photospheric X-ray spectrum. ! question: 10 section: 1 line_1: Computer resources: line_2: i) Micro VAX 3300 + 2 VAX Station 3100 of the DAN node Bamberg line_3: ii) Cray YMP/EL of the Universitaet Erlangen-Nuernberg line_4: iii) Cray YMP, Landesvektorrechner Muenchen line_5: iv) VAX 8550 of the "Rechenzentrum der Universitaet Kiel" line_6: v) Cray X-MP of the "Rechenzentrum der Universitaet Kiel" line_7: vi) Cluster of Unix-Workstations of the Institut fuer Theoretische Physik line_8: und Sternwarte der Universitaet Kiel line_10: Research assistance: Dr. H. Drechsel (system manager of the Bamberg DAN node), line_11: Dipl.Ing. G.Jonas (Kiel, data reduction specialist), ! !end of general form text general_form_address: lname: HEBER fname: ULRICH category: PI inst: 5578 city: D country: GERMANY phone: +49 9519522214 telex: HEBER@STERNWARTE.UNI-ERLANGEN.D400.DE ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: FEIGE46 descr_1: A,108 pos_1: RA= 11H37M26.450S +/- 0.1S, pos_2: DEC=+14D10'15.20" +/- 0.1", pos_3: PLATE-ID=019N equinox: 2000 pos_epoch_bj: J pos_epoch_yr: 2000.00 fluxnum_1: 1 fluxval_1: V=13.3 +/- 0.2, TYPE=SDO fluxnum_2: 2 fluxval_2: F-CONT(1500)=1.1 +/- 0.2E-12 fluxnum_3: 3 fluxval_3: F-CONT(1460)=1.2 +/- 0.2E-12 fluxnum_4: 4 fluxval_4: F-CONT(1400)=1.4 +/- 0.2E-12 fluxnum_5: 5 fluxval_5: F-CONT(1340)=1.7 +/- 0.2E-12 fluxnum_6: 6 fluxval_6: B-V=-0.3+/-0.1 fluxnum_7: 7 fluxval_7: E(B-V)=0.0+/-0.1 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: FEIGE46 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 1.8S fluxnum_1: 3 priority: 1 param_1: SEARCH-SIZE=3 param_2: BRIGHT=RETURN param_3: LOCATE=YES param_4: MAP=DEF req_1: CYCLE 4; req_2: ONBOARD ACQ FOR 1.1; comment_1: STEP TIME = 0.2S; comment_2: EXPECTED COUNTRATE 33000 C/S ! linenum: 1.100 targname: FEIGE46 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 61.2S fluxnum_1: 3 priority: 1 req_1: CYCLE 4; req_2: ONBOARD ACQ FOR 1.2-1.5; comment_1: STEP TIME = 0.6S; comment_2: EXP. COUNTRATE 33000 C/S comment_3: TOO BRIGHT FOR STEP-TIME 1.6S? ! linenum: 1.200 targname: FEIGE46 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1485-1518 num_exp: 4 time_per_exp: 22.5M s_to_n: 50 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=FOUR req_1: CYCLE 4; ! linenum: 1.300 targname: FEIGE46 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1440-1473 num_exp: 2 time_per_exp: 21.5M s_to_n: 40 fluxnum_1: 3 priority: 1 param_1: FP-SPLIT=FOUR req_1: CYCLE 4; ! linenum: 1.400 targname: FEIGE46 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1380-1413 num_exp: 2 time_per_exp: 18M s_to_n: 40 fluxnum_1: 4 priority: 1 param_1: FP-SPLIT=FOUR req_1: CYCLE 4; ! linenum: 1.500 targname: FEIGE46 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1325-1358 num_exp: 1 time_per_exp: 26M s_to_n: 30 fluxnum_1: 5 priority: 1 param_1: FP-SPLIT=FOUR req_1: CYCLE 4; ! ! end of exposure logsheet ! No scan data records found