Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5346 Report Date: 10-Aug-95:14:55 Version: ********** Check-in Date: ********** 1.Proposal Title: FUNDAMENTAL EVOLUTIONARY PARAMETERS OF B-SUPERGIANTS IN THE POST MAIN SEQUENCE GAP OF THE HR DIAGRAM: CYCLE4 MEDIUM ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID HOT STARS GO Sub Category MASSIVE STARS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Daniel Lennon 5588 GERMANY +49-89-9220942 ------------------------------------------------------------------------------------ 7. Abstract All stellar evolution calculations to date predict, for massive stars, the existence of a post main sequence gap in the Hertzsprung-Russell diagram. This gap is not observed, on the contrary the relevant region of the HR diagram is populated by early B supergiants. Consequently, the evolutionary status of these stars is uncertain, various attempts at explaining them range from post red supergiant evolution, diffusion processes in their main sequence progenitors or enhanced mass loss near the Humphreys-Davidson limit. These scenarios predict altered H/He ratios and CNO abundances as well as reduced masses in comparison to 'normal' stars, and this information is the key to understanding their evolutionary status. We propose to use FOS to obtain high S/N spectral data for four LMC early-B supergiants covering the wavelength range 1150-2300 A which will be analysed together with existing high resolution optical data to provide reliable values of the effective temperature, surface gravity, chemical composition, mass loss rate and stellar mass of each object. Highly sophisticated model atmosphere, stellar wind and 'unified' model atmosphere codes will be used in this analysis. The resulting information will be used to discriminate between various evolutionary scenarios and to constrain new stellar evolution calculations. A comparison with a parallel project for the Milky Way will yield valuable information on the importance of metallicity. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 1.28 par: 0 10. Num targs pri: 4 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5346 PI: Daniel Lennon Proposal Title: FUNDAMENTAL EVOLUTIONARY PARAMETERS OF B-SUPERGIANTS IN THE POST MAIN SEQUENCE GAP OF THE HR DIAGRAM: CYCLE4 MEDIUM ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Daniel J Lennon MUNICH UNIVERSITY GERMANY X Rolf-Peter Kudritzki MUNICH UNIVERSITY GERMANY X Nolan R Walborn STSCI USA Bruce Bohannan NOAO USA Edward L Fitzpatrick PRINCETON UNIVERSITY USA Norbert Langer MAX PLANCK INSTITUTE FOR GERMANY X ASTROPHYSICS Stephen A Voels NASA/GSFC USA John D Hillier UNIVERSITY OF PITTSBURGH USA Keith Butler MUNICH UNIVERSITY GERMANY X Dirk Husfeld MUNICH UNIVERSITY GERMANY X Adi Pauldrach MUNICH UNIVERSITY GERMANY X Joachim Puls MUNICH UNIVERSITY GERMANY X Rudi Gabler MUNICH UNIVERSITY GERMANY X Sylvia Becker MUNICH UNIVERSITY GERMANY X ------------------------------------------------------------------------------------ 3. Description of proposed observations. Due to time constraints we will observe 4 out of a total of 7 specified (at Phase I) supergiants in the LMC. We have selected one normal and one peculiar star at each of the spectral types B1 and B1.5. The observational strategy is to complete observations for one pair of stars before proceeding with a second pair, hence we have prioritorized observations but note that these ma be interchanged to facilitate scheduling. The V magnitudes range from 11.4 to 12.1 and the spectral types are well determined from both intermediate slit spectroscopy and high dispersion echelle spectroscopy. We require two spectra of each star using the FOS and the blue detector with gratings G130H and G190H at a S/N of approximately 70. The spectral coverage will thus run from 1150A to 2300A and will contain all the important wind lines needed for our analysis; NV 1239,1243, CII 1334,1336, SiIV 1394,1403, CIV 1548,1551 and AlIII 1855,1863, plus a large number of photospheric lines due to Fe and Ni. The resolution of FOS ( approximately 200 km/s) is not a problem for the analysis of the wind features while the photospheric line spectrum suffers from such blending problems that spectral sysnthesis techniques are necessary to derive abundances in any case - provided the S/N is approximately that requested. NOTE THAT THESE TARGETS ARE ALL THE SUBJECT OF A CYCLE 3 (ID 4556) SUPPLEMENTAL PROPOSAL. IN THE EVENT OF SUCCESSFUL COMPLETION OF ANY PART OF PROGRAM 4556 WE REQUEST THE OPPORTUNITY TO REVIEW THE SELECTION OF TARGETS FOR THE PRESENT PROGRAM FROM THE ORIGINAL LIST OF 7 STARS. Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The UV spectrum is essential for our analysis as it provides crucial information about the atmospheres and winds of our objects. The UV stellar wind lines provide us with estimates of v(infinity) as well as being important diagnostics of the stellar wind velocity, ionization structure and mass loss rate. Futhermore, there are a number of elements with no, or very weak, optical lines but with a rich UV spectrum (Fe, Ni), these are also a dominant contributor to the radiative line force. Experience gained with IUE on targets of similar apparent magnitudes has demonstrated that the present program is not feasible with IUE given our combined requirements of S/N, resolution and crowding problems in our target fields. HST/FOS observations are therefore necessary for this project. Extensive ground based programs have been ongoing in this area for a number of years. NRW and EF have been involved in spectral classification of hot stars in the Magellanic Clouds using low and intermediate resolution observations for some time. In addition ALL of the targets have been observed in the visible at intermediate and high dispersions using, for example, ESO 3.6m and CTIO 4m telescopes. For all of the target stars, low dispersion SWP IUE spectra are available and thus it is possible to accurately estimate the exposure times needed to reach a photon counting S/N of 100 for each of the two gratings. The requested signal to noise is based upon previous experience gained with this instrumentation and is necessary to enable us to measure terminal velocities, by fitting the wind lines, to within 150km/s and for the synthesis of line blends in the UV. ACQ/PEAK exposure times were estimated from the observed B magnitudes. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. No special calibrations required. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Target positions have been obtained from GASP frames and cross-checked against the Guide Star Catalog. All objects are guide stars. ------------------------------------------------------------------------------------ 9. Description of previous HST work. GTO No. 1215 ULTRAVIOLET SPECTRAL ATLAS OF O-STARS IN THE MILKY WAY AND MAGELLANIC CLOUDS (RPK, NRW) GO No. 2233/4110 THE PHYSICS OF MASSIVE O-STARS IN DIFFERENT PARENT GALAXIES (RPK, NRW, SAV, KB, DH, AP, JP) GO No. 2581 STELLAR WINDS OF MASSIVE STARS IN NEARBY GALAXIES (RPK) GO No. 4550 MASSIVE STAR EVOLUTION FROM CARBON AND OXYGEN ABUNDANCES IN LMC WC STARS (JDH, RPK, SAV, KB, DJL) The present proposal is not directly related to any of the above proposals except in so far as it concerns the same general topic of quantitative spectroscopy of hot massive stars. The present proposal is specifically aimed at elucidating the evolutionary history of the early B supergiants, a problem none of the above proposals addresses adequately. Note here that the present proposal is a revision of GO 4556 which was granted SUPPLEMENTAL status in Cycle 3. GTO proposal 1215 and GO proposal 2581 are completed and results have been published in the literature (see below for examples). GO proposals 2233/4110 and 4550 are incomplete. The former still has observations of 4 early O-stars in the SMC outstanding which are crucial to interpretation of the metallicity dependence of mass loss rates in the galaxy, LMC and SMC. Nevertheless preliminary results for some stars have been published. To date no data for proposal 4550 have been obtained. Page 4 ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Munich University: Data reduction and analysis facilities and personal are described under section 6. There are no problems with the funding of the necessary computer calculations required for this project. In addition to those people from Munich University listed under "Investigators" above, several Ph.D. students (S. Haser, F. Sellmaier, F. Navarro U. Springmann, C. Kronberg) will work full time on the project. Funds for travel, preparation of observations, reduction, etc will also be available. ------------------------------------------------------------------------------------ 11. Address Information Name: DANIEL LENNON Category: PI Institution: 5588 Address: INSTITUT F ASTRONOMY U ASTROPHYSIK DER UNIVERSITAET SCHEINERSTRASSE 1 81679 MUENCHEN 80 City: MUNICH State: Zip Code: Country: GERMANY Telephone: +49-89-92209423 Telex (or e-mail): DJL@USM.UNI-MUENCHEN.DE ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5346 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 SK-69D43 B,113; PLATE-ID=05ZW, 2000 V = +279 1 V = 11.9 , TYPE=B1IA HDE268809 HOST=LMC RA = 04H 56M 10.51S +/- 2 B-V = -0.1 GSC9161- TYPE=B1IA 0.5", 3 E(B-V) = 0.10 00737 DEC = -69D 15' 38.5" +/- 4 F-CONT(1300) = 1.0 +/- 0.1 E-12 0.5" 5 F-CONT(1600) = 0.6 +/- 0.1 E-12 ------------------------------------------------------------------------------------------------------------------------------------ 2 SK-68-11 B,113; RA = 5H 31M 0.92S +/- 0.5", 2000 1 V = 12.01 +/- 0.3, TYPE=BC1IA HOST=LMC DEC = -68D 53' 56.7" +/- 2 B-V = -0.08 TYPE=BC1IA 0.5", 3 U-B = -0.89 PLATE-ID=06b0 ------------------------------------------------------------------------------------------------------------------------------------ 3 SK-67D14 B,113; PLATE-ID=06AF, 2000 V = +270 1 V = 11.5 , TYPE=B1.5IA HDE268685 HOST=LMC RA = 04H 54M 31.92S +/- 2 B-V = -0.1 GSC8889- TYPE=B1.5IA 0.5", 3 E(B-V) = 0.06 00517 DEC = -67D 15' 24.9" +/- 4 F-CONT(1300) = 1.4 +/- 0.1 E-12 0.5" 5 F-CONT(1600) = 1.0 +/- 0.1 E-12 ------------------------------------------------------------------------------------------------------------------------------------ 4 SK-69D228 B,113; PLATE-ID=05ZW, 2000 V = +270 1 V = 12.1 , TYPE=BC1.5IA GSC9163- HOST=LMC RA = 05H 37M 9.36S +/- 2 B-V = 0.1 00764 TYPE=BC1.5IA 0.5", 3 E(B-V) = 0.23 DEC = -69D 20' 19.1" +/- 4 F-CONT(1300) = 0.3 +/- 0.05 E-12 0.5" 5 F-CONT(1600) = 0.3 +/- 0.05 E-12 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5346 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 SK-69D43 FOS/BL ACQ/ 4.3 G400H SCAN-STEP- 1 0.045S 1 1 ONBOARD ACQ FOR 12 PEAK Y=1.204 CYCLE 4 / 11.00- SEARCH-SIZE-X=1 46.00 SEARCH-SIZE-Y=3 COND IF THIS TARGET NOT DONE IN CYCLE 3 SUPPLEMENTAL PROGRAM 4556 / 11 -46 ------------------------------------------------------------------------------------------------------------------------------------ 12 SK-69D43 FOS/BL ACQ/ 1.0 G400H SCAN-STEP- 1 0.18S 1 1 ONBOARD ACQ FOR 13 PEAK X=.602 SCAN-STEP- Y=.602 SEARCH-SIZE-X=6 SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 13 SK-69D43 FOS/BL ACQ/ 0.5 G400H SEARCH-SIZE-X=3 1 0.135S 1 1 ONBOARD ACQ FOR 14 PEAK SEARCH-SIZE-Y=3 SCAN-STEP- X=0.30 SCAN-STEP- Y=0.30 ------------------------------------------------------------------------------------------------------------------------------------ 14 SK-69D43 FOS/BL ACQ/ 0.3 G400H SCAN-STEP- 1 0.375S 1 1 ONBOARD ACQ FOR 15 PEAK X=.172 -16 SCAN-STEP- Y=.172 SEARCH-SIZE-X=5 SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ 15 SK-69D43 FOS/BL ACCUM 0.3 G130H 1 562.0S 70 4 1 ------------------------------------------------------------------------------------------------------------------------------------ 16 SK-69D43 FOS/BL ACCUM 0.3 G190H 1 312.0S 75 5 1 ------------------------------------------------------------------------------------------------------------------------------------ 21 SK-68-11 FOS/BL ACQ/ 4.3 G400H SCAN-STEP- 1 1S 1 1 ONBOARD ACQ FOR 22 PEAK Y=1.204 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 22 SK-68-11 FOS/BL ACQ/ 1.0 G400H SCAN-STEP- 1 1S 1 1 ONBOARD ACQ FOR 23 PEAK X=.602 SCAN-STEP- Y=.602 SEARCH-SIZE-X=6 SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5346 [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 23 SK-68-11 FOS/BL ACQ/ 0.5 G400H SEARCH-SIZE-X=3 1 1S 1 1 ONBOARD ACQ FOR 24 PEAK SEARCH-SIZE-Y=3 SCAN-STEP- X=0.30 SCAN-STEP- Y=0.30 ------------------------------------------------------------------------------------------------------------------------------------ 24 SK-68-11 FOS/BL ACQ/ 0.3 G400H SCAN-STEP- 1 1S 1 1 ONBOARD ACQ FOR 25 PEAK X=.172 -26 SCAN-STEP- Y=.172 SEARCH-SIZE-X=5 SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ 25 SK-68-11 FOS/BL ACCUM 0.3 G130H 1 511.0S 70 1 ------------------------------------------------------------------------------------------------------------------------------------ 26 SK-68-11 FOS/BL ACCUM 0.3 G190H 1 268.0S 70 1 ------------------------------------------------------------------------------------------------------------------------------------ 31 SK-67D14 FOS/BL ACQ/ 4.3 G400H SCAN-STEP- 1 0.045S 1 1 ONBOARD ACQ FOR 32 PEAK Y=1.204 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 32 SK-67D14 FOS/BL ACQ/ 1.0 G400H SCAN-STEP- 1 0.18S 1 1 ONBOARD ACQ FOR 33 PEAK X=.602 SCAN-STEP- Y=.602 SEARCH-SIZE-X=6 SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 33 SK-67D14 FOS/BL ACQ/ 0.5 G400H SEARCH-SIZE-X=3 1 0.135S 1 1 ONBOARD ACQ FOR 34 PEAK SEARCH-SIZE-Y=3 SCAN-STEP- X=0.30 SCAN-STEP- Y=0.30 ------------------------------------------------------------------------------------------------------------------------------------ 34 SK-67D14 FOS/BL ACQ/ 0.3 G400H SCAN-STEP- 1 0.375S 1 1 ONBOARD ACQ FOR 35 PEAK X=.172 -36 SCAN-STEP- Y=.172 SEARCH-SIZE-X=5 SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ 35 SK-67D14 FOS/BL ACCUM 0.3 G130H 1 402.0S 70 4 1 ------------------------------------------------------------------------------------------------------------------------------------ 36 SK-67D14 FOS/BL ACCUM 0.3 G190H 1 187.0S 70 5 1 ------------------------------------------------------------------------------------------------------------------------------------ 41 SK-69D228 FOS/BL ACQ/ 4.3 G400H SCAN-STEP- 1 0.045S 1 1 ONBOARD ACQ FOR 42 PEAK Y=1.204 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5346 [ 8] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 42 SK-69D228 FOS/BL ACQ/ 1.0 G400H SCAN-STEP- 1 0.18S 1 1 ONBOARD ACQ FOR 43 PEAK X=.602 SCAN-STEP- Y=.602 SEARCH-SIZE-X=6 SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 43 SK-69D228 FOS/BL ACQ/ 0.5 G400H SEARCH-SIZE-X=3 1 0.135S 1 1 ONBOARD ACQ FOR 44 PEAK SEARCH-SIZE-Y=3 SCAN-STEP- X=0.30 SCAN-STEP- Y=0.30 ------------------------------------------------------------------------------------------------------------------------------------ 44 SK-69D228 FOS/BL ACQ/ 0.3 G400H SCAN-STEP- 1 0.375S 1 1 ONBOARD ACQ FOR 45 PEAK X=.172 -46 SCAN-STEP- Y=.172 SEARCH-SIZE-X=5 SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ 45 SK-69D228 FOS/BL ACCUM 0.3 G130H 1 1742.0S 70 4 1 ------------------------------------------------------------------------------------------------------------------------------------ 46 SK-69D228 FOS/BL ACCUM 0.3 G190H 1 625.0S 70 5 1 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5346 [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCAN-STEP-Y=1.204 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 SCAN-STEP-X=.602 SCAN-STEP-Y=.602 SEARCH-SIZE-X=6 SEARCH-SIZE-Y=2 SEARCH-SIZE-X=3 SCAN-STEP-X=0.30 SCAN-STEP-Y=0.30 SCAN-STEP-X=.172 SCAN-STEP-Y=.172 SEARCH-SIZE-X=5 SEARCH-SIZE-Y=5 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 1.28 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category MASSIVE STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 12; CYCLE 4 / 11.00-46.00; COND IF THIS TARGET NOT DONE IN CYCLE 3 SUPPLEMENTAL PROGRAM 4556 / 11-46 ONBOARD ACQ FOR 13; ONBOARD ACQ FOR 14; ONBOARD ACQ FOR 15-16; ONBOARD ACQ FOR 22 ONBOARD ACQ FOR 23; ONBOARD ACQ FOR 24; ONBOARD ACQ FOR 25-26; ONBOARD ACQ FOR 32 ONBOARD ACQ FOR 33; ONBOARD ACQ FOR 34; ONBOARD ACQ FOR 35-36; ONBOARD ACQ FOR 42 ONBOARD ACQ FOR 43; ONBOARD ACQ FOR 44; ONBOARD ACQ FOR 45-46; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G400H G130H G190H ------------------------------------------------------------------------------------------------------------------------------------ Target Names SK-69D43 HDE268809 GSC9161-00737 SK-68-11 SK-67D14 HDE268685 GSC8889-00517 SK-69D228 GSC9163-00764 ------------------------------------------------------------------------------------------------------------------------------------