Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4550c Report Date: 09-May-96:19:42 Version: ********** Check-in Date: ********** 1.Proposal Title: CONSTRAINTS ON MASSIVE STAR EVOLUTION FROM CARBON AND OXYGEN ABUNDANCES IN LMC WC STARS. CYC3HIGH ------------------------------------------------------------------------------------ 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 John D Hillier UNIVERSITAT MUENCHEN GERMANY ------------------------------------------------------------------------------------ 7. Abstract High signal-to-noise UV FOS spectra of a sample of WC-type Wolf-Rayet stars in the LMC will be obtained to determine C/He and O/C abundance ratios. These abundance ratios will provide urgently required constraints on the He-burning stage of the evolution of massive stars. The surface C/He and O/C abundance ratios in WC stars are influenced by mass loss, convection and overshooting, and the (uncertain) 12C(ALPHA,GAMMA)16O reaction rate. The spectra will be analyzed using sophisticated non-LTE radiative transfer codes which allow for spherical extension and stellar winds, and which incorporate the latest atomic data. Our quantitative analysis will also allow a determination of fundamental stellar parameters (eg Rstar, Teff), abundances of species such as Fe and Si, and accurate mass loss rates. These, and the C and O abundance determinations, will allow much tighter constraints to be placed on the evolution of massive stars. Starburst galaxies are currently an active area of research. Massive stars, including W-R stars, are seen to be playing a key role in the dynamics and evolution of these systems. It is imperative that we understand the evolution and properties of massive stars in the galaxy and LMC (where they are amenable to detailed spectroscopic studies) if we are to make reliable inferences concerning star formation rates, nucleosynthesis yields, and initial mass functions etc in starburst systems. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 13.28 par: 0 10. Num targs pri: 4 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4550c PI: John D Hillier Proposal Title: CONSTRAINTS ON MASSIVE STAR EVOLUTION FROM CARBON AND OXYGEN ABUNDANCES IN LMC WC STARS. CYC3HIGH ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi John D Hillier UNIVERSITAT MUENCHEN GERMANY X Wolf-Rainer Hamann UNIVERSITAT KIEL GERMANY X Ulf Wessolowski UNIVERSITAT KIEL GERMANY X Keith Butler UNIVERSITAT MUENCHEN GERMANY X Rolf P Kudritzki UNIVERSITAT MUENCHEN GERMANY X Daniel J Lennon UNIVERSITAT MUENCHEN GERMANY X Stephen A Voels UNIVERSITAT MUENCHEN GERMANY X ------------------------------------------------------------------------------------ 2. Scientific Justification. Justification not required for phase 2. ------------------------------------------------------------------------------------ 3. Description of proposed observations. Using FOS we will observe 4 WC4 stars in the LMC. Three sets of spectra, covering the wavelength ranges 1150-1606A (grating G130H), 1573-2330A (G190H), and 2222-3301A (G270H), will be obtained for each star. For HD32402, we will aim for a continuum S to N ratio in excess of 70:1, while for the other 3 stars we will aim for a S/N ratio of 40:1. The blue digicon will be used for all 3 regions. Although the red digicon could be used for region 2 (G190H), we feel that its rapid response variation near 1600A would adversely affect our ability to reliably combine this spectrum with that extending from 1150 to 1606A. The region from 1500-1700A is particularly important as it contains the CIV 1550 resonance doublet, and HeII 1640 whose formation is somewhat different from other HeII emission lines. We chose the blue detector for G270H because of detector stability (ie. one detector used continuously for all exposures), because of the slight increase in wavelength range allowing greater overlap with ground based observations, and because of overall system efficiency. As recommended by the TAC, observations of a further 3WC stars, and one WO star will be requested in a subsequent cycle. The selected stars have been the subject of an extensive optical observational study by Torres et al (1986), and show no evidence for binarity. They represent a complete sample of the known single WC/WO stars in the LMC. The v magnitudes (corrected for emission lines) range from 14th to 16.5th magnitude (Vacca and Torres-Dodgen 1990). Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The UV spectrum is essential for our analysis as it provides crucial information not available in the optical spectral region. The rich emission-line spectrum means that there are few (relatively) blend free lines ideally suited to abundance analyses. Many of these (eg CIV 1550) lie in the UV. Lines in the optical region are formed by recombination. However, the UV contains many lines formed by collisional processes. These lines provide additional diagnostics on the wind structure. Lines due to Fe (principally FeV and FeVI) are only observable in the UV. The targets are not suitable for IUE observations given our requirements of signal to noise, resolution, and problems with crowding in our target fields. The proposers have had extensive experience in modelling W-R and O stars. Some ground-based data are already available for the present stars, and further high signal-to-noise ground observations will be obtained for the project. A parallel study to determine O and C abundances in galactic WC stars is in progress by Hillier and Bohannan. In addition, Koesterke et al (1992) have established a coarse grid of WC models that can be used to provide initial estimates of the stellar parameters. They are using this grid to determine C/He abundances and stellar parameters for a sample of galactic WC stars. All four stars have been observed with the IUE SWP camera at low dispersion, and hence from the IUE continuum fluxes we have been able to estimate required exposure times. In addittion, all 4 stars have flux calibrated optical spectra, which, in conjunction with the IUE spectra, allows acquizition fluxes to be estimated. For 2 stars we require a signal-to-noise ratio of 40:1 per resolution element (diode) which was calculated on the basis of continuum fluxes at 1285A, 1690A, and 2200A). A signal-to-noise ratio of 40 to 1 will allow us to obtain high quality profiles, to detect blends and weak absorption features, and allow good continuum placement. The latter is essential for accurate profiles, and if we are to observe the broad dielectronic features predicted by our models. The need for high resolution and high S/N in studying W-R spectra has previously been stressed, for example, by Bappu (1973). For the brightest WC star (HD32402) we have opted for a S/N of 70:1 per resolution element. This enhanced S/N will serve 2 purposes. It will allow us to obtain useful data down to 1160A, where the detector/system response has fallen by more than a factor of 7 from 1285A. In this region CIII 1176, and additional FeVI lines are to be found. Secondly, the higher S/N will allow this spectrum to be used as a 'template' to assist in the continuum definition, reddening determinations, and modelling of the other WC stars. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. NO GAP justification: The UV spectra of early type stars is known to vary with time. In order to obtain completely consistent UV spectra over our spectral range, we require that the spectra for our 3 wavelength ranges be obtained as close together as possible. The order does not matter hence we have not used the SEQ requirement. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. No special calibrations etc required. Page 4 ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Data Reduction: As of 1-Sep-1993 the PI will be commencing an associate professor position at the university of Pittsburgh. Some workstations are available, on a limited basis, for reduction however the PI intends to invest in a high powered workstation for both reduction and model development. We have requested ST funds, and intend to purchase the workstation on a 50% cost sharing basis with the University of Pittsburgh. In order to partially verify the reduction procedures, data reduction will be performed independently in both Munich and in Pittsburgh. The institute in Munich has a cluster of 12 DEC VAXStations (3 x 3200, 2 x 3100, 7 x 2000, 21 VUPS total, several with 8-bit color display) plus a cluster of DEC Decstations (2 x 5000, 1 x VT1300,all with 8 -bit color display) on which all major astronomical software environments (IDL, IRAF, IRAF/STSDAS and MIDAS) are installed. Data calibration and reduction will be performed using the latest software and calibration databases available locally or at the nearby ST-ECF in Garching. Note that personnel have already gained experience with FOS data reduction as a result of a Cycle 1 allocation of time and are familiar with the procedures and software. The analysis will be carried out by performing spectral synthesis using state of the art non-LTE wind codes. Two independent codes are available, allowing important consistency checks. These codes have been developed by the PI (eg Hillier 1989, 1990), and by Hamann, Schmutz and collaborators in Kiel (eg Hamman and Wessolowski 1990). All codes are continually undergoing improvements and revisions as assumptions are relaxed, and as the latest atomic data are incorporated. They have been used with great success in investigating the structure of W-R stars (Hillier 1987,1988,1989, Schmutz et al 1989). In addition we will have access to the extensive set of non-LTE codes developed by Kudritzki and collaborators (eg Gabler et al 1989) which have been used with great success modelling O stars. The code developed by the PI allows for the full non-LTE treatment of H, HeI, CII- CIV, NIII-NV, and OIII-OVI. Recently Becker and Butler (1992) have developed an extensive FeV model atom. The model atom will soon be incorporated into the code, and will be a first step in allowing the full treatment of non-LTE line blanketing. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Revised target positions, obtained with GASP, are now supplied with the Phase 2 proposal. ------------------------------------------------------------------------------------ 9. Description of previous HST work. GO No. 2233/4110 THE PHYSICS OF MASSIVE O-STARS IN DIFFERENT PARENT GALAXIES GTO No. 1215 ULTRAVIOLET SPECTRAL ATLAS OF O-STARS IN THE MILKY WAY AND MAGELLANIC CLOUDS The present proposal is related to these in so far as they are all concerned with the general topic of the physics and nature of hot massive stars in other galaxies. Stellar parameters and abundances (including iron) have so far been obtained for 3 very massive early O-type stars in the LMC. In addition, estimates have been made of the mass-loss rates, terminal velocities and hence the stellar masses and distances. The 15 other targets from this project are due to be observed before the end of this year. First Results from the GHRS: Spectroscopic determination of stellar parameters of an O3f star, Melnick 42, in the Large Magellanic Cloud, Heap, S.R., Altner, B., Ebbets, D., Hubeny, I., Hutchings, J.S., Kudritzki, R.P. Voels, S.A., Haser, S., Pauldrach, A., Puls, J., Butler, K., 1991., Ap. J. Let., 377, L29. Kudritzki, R.P., Becker, S.R., Butler, K., Gabler, R., Haser, S., Husfeld, D., Lennon, D.J., Pauldrach, A., Puls, J., Voels, S. 1992b, 'Hot Stars and the Hubble Space Telescope', in 'Science with the Hubble Space Telescope', ESO, in press. Page 5 ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). University of Pittsburgh: As noted in Section 6, the university has agreed to provide 50% funding of a high powered work station for reduction (some work stations are already available for this) and extensive model development. In addition, the PI will have access to the Pittsburgh Supercomputer center for more extensive model calculations. 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, either at Kiel, or Munich. Funds for travel, preparation of observations, reduction, etc will also be available. ------------------------------------------------------------------------------------ 11. Address Information Name: JOHN D HILLIER Category: PI Institution: Universitat Muenchen Address: SCHEINERSTRASSE 1 8000 MUENCHEN 80 City: MUENCHEN/MUNICH State: Zip Code: Country: GERMANY Telephone: +49-89-9220940 Telex (or e-mail): ------------------------------------------------------------------------------------ Name: JOHN D HILLIER Category: PI Institution: UNIVERSITY OF PITTSBURGH Address: DEPARTMENT OF PHYSICS AND ASTRONOMY 3941 O'HARA STRREET 100 ALLEN HALL City: PITTSBURGH, PA 15260 State: Zip Code: Country: USA Telephone: 412-624-9000 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 4550c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 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 HD32402 WS6 B,102; PLATE-ID=05ZW, 2000 V= +280 COMP 1 V=13.30 +/- 0.1, TYPE=WC4 BR10 HOST=LMC RA = 04H 57M 24.191S +/- 2 B-V=-0.19 +/- 0.05 TYPE=WC4 0.50", 3 E(B-V)=0.07 +/- 0.03 DEC = -68D 23' 57.23" +/- 4 F-CONT(5560)=9.0 +/- 0.5 E-15 0.50" 5 F-CONT(2225)=1.7 +/- 0.2 E-13 6 F-CONT(1690)=4.5 +/- 0.1 E-13 7 F-CONT(1285)=1.0 +/- 0.1 E-12 Comments: V=14.01 +/- 0.1 E(B-V)=0.06 ------------------------------------------------------------------------------------------------------------------------------------ 11 HD37026 WS31 B,102; PLATE-ID=05ZW, 2000 V= +280 1 V=13.60 +/- 0.1, TYPE=WC4 BR43 HOST=LMC RA = 05H 30M 12.216S +/- 2 B-V=-0.31 +/- 0.05 TYPE=WC4 0.50", 3 E(B-V)=0.06 +/- 0.02 DEC = -67D 26' 08.49" +/- 4 F-CONT(5560)=7.0 +/- 0.5 E-15 0.50" 5 F-CONT(2225)=6.9 +/- 0.5 E-14 6 F-CONT(1690)=1.8 +/- 0.2 E-13 7 F-CONT(1285)=4.6 +/- 0.5 E-13 Comments: V=14.46 +/- 0.1 E(B-V)=0.05 ------------------------------------------------------------------------------------------------------------------------------------ 21 HD37680 WS35 B,102; PLATE-ID=05ZW, 2000 V= +280 1 V=13.35 +/- 0.1, TYPE=WC4 BR50 HOST=LMC RA = 05H 34M 19.387S +/- 2 B-V=-0.20 +/- 0.05 TYPE=WC4 0.50", 3 E(B-V)=0.01 +/- 0.03 DEC = -69D 45' 10.08" +/- 4 F-CONT(5560)=8.0 +/- 0.5 E-15 0.50" 5 F-CONT(2225)=9.2 +/- 0.5 E-14 6 F-CONT(1690)=1.7 +/- 0.2 E-13 7 F-CONT(1285)=4.5 +/- 0.1 E-13 Comments: V=14.27 E(B-V)=0.01 ------------------------------------------------------------------------------------------------------------------------------------ 31 HD32257 WS4 B,102; PLATE-ID=05ZW, 2000 V= +280 1 V=14.27 +/- 0.1, TYPE=WC4 BR8 HOST=LMC RA = 04H 56M 02.952S +/- 2 B-V=-0.20 +/- 0.05 TYPE=WC4 0.50", 3 E(B-V)=0.07 +/- 0.03 DEC = -69D 27' 21.59" +/- 4 F-CONT(5560)=3.5 +/- 0.2 E-15 0.50" 5 F-CONT(2225)=3.2 +/- 0.2 E-14 6 F-CONT(1690)=7.8 +/- 0.2 E-14 7 F-CONT(1285)=2.2 +/- 0.1 E-13 Comments: V=15.12 +/- 0.1 E(B-V)=0.06 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4550c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 11 HD32402 FOS/BL ACQ/ 4.3 MIRROR FAINT=940.0 1 0.66S 4 1 CYCLE 3/11.00- BINARY BRIGHT=33000.0 15.00 GROUP 11.00- 15.00 NO GAP ONBOARD ACQ FOR 12.00 ------------------------------------------------------------------------------------------------------------------------------------ 12 HD32402 FOS/BL ACQ/ 0.25X2. MIRROR TYPE=UP 1 1.2S 4 1 ONBOARD ACQ FOR PEAK 0 13.00 SPATIAL SCAN ------------------------------------------------------------------------------------------------------------------------------------ 13 HD32402 FOS/BL ACCUM 0.25X2. G130H 1 2350S 70 5 1 0 ------------------------------------------------------------------------------------------------------------------------------------ 14 HD32402 FOS/BL ACCUM 0.25X2. G190H 1 980S 70 6 1 0 ------------------------------------------------------------------------------------------------------------------------------------ 15 HD32402 FOS/BL ACCUM 0.25X2. G270H 1 365S 70 7 1 0 ------------------------------------------------------------------------------------------------------------------------------------ 21 HD37026 FOS/BL ACQ/ 4.3 MIRROR FAINT=660.0 1 0.66S 4 2 CYCLE 3/21.00- BINARY BRIGHT=33000.0 25.00 GROUP 21.00- 25.00 NO GAP ONBOARD ACQ FOR 22.00 ------------------------------------------------------------------------------------------------------------------------------------ 22 HD37026 FOS/BL ACQ/ 0.25X2. MIRROR TYPE=UP 1 0.90S 4 2 ONBOARD ACQ FOR PEAK 0 23.00 SPATIAL SCAN ------------------------------------------------------------------------------------------------------------------------------------ 23 HD37026 FOS/BL ACCUM 0.25X2. G130H 1 1740S 40 5 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 24 HD37026 FOS/BL ACCUM 0.25X2. G190H 1 825S 40 6 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 25 HD37026 FOS/BL ACCUM 0.25X2. G270H 1 300S 40 7 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 31 HD37680 FOS/BL ACQ/ 4.3 MIRROR FAINT=940.0 1 0.66S 4 2 CYCLE 3/31.00- BINARY BRIGHT=33000.0 35.00 GROUP 31.00- 35.00 NO GAP ONBOARD ACQ FOR 32.00 ------------------------------------------------------------------------------------------------------------------------------------ 32 HD37680 FOS/BL ACQ/ 0.25X2. MIRROR TYPE=UP 1 0.93S 4 2 ONBOARD ACQ FOR PEAK 0 33.00 SPATIAL SCAN ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4550c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 33 HD37680 FOS/BL ACCUM 0.25X2. G130H 1 1800S 40 5 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 34 HD37680 FOS/BL ACCUM 0.25X2. G190H 1 840S 40 6 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 35 HD37680 FOS/BL ACCUM 0.25X2. G270H 1 220S 40 7 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 41 HD32257 FOS/BL ACQ/ 4.3 MIRROR FAINT=660.0 1 1.11S 4 2 CYCLE 3/41.00- BINARY BRIGHT=33000.0 45.00 GROUP 41.00- 45.00 NO GAP ONBOARD ACQ FOR 42.00 ------------------------------------------------------------------------------------------------------------------------------------ 42 HD32257 FOS/BL ACQ/ 0.25X2. MIRROR TYPE=UP 1 2.23S 4 2 ONBOARD ACQ FOR PEAK 0 43.00 SPATIAL SCAN ------------------------------------------------------------------------------------------------------------------------------------ 43 HD32257 FOS/BL ACCUM 0.25X2. G130H 1 3100S 37 5 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 44 HD32257 FOS/BL ACCUM 0.25X2. G190H 1 1920S 40 6 2 0 ------------------------------------------------------------------------------------------------------------------------------------ 45 HD32257 FOS/BL ACCUM 0.25X2. G270H 1 660S 40 7 2 0 ------------------------------------------------------------------------------------------------------------------------------------ Scan Paramters Form Proposal ID: 4550c [ 9] ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 1 Exposure Logsheet lines: 12.00 FGS Scan: DWELL Dwell Only: dwell points/line: 7 Seconds per dwell: 1.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 0.4000 Angle between sides (degrees) 0.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0000 PA of first scan line (degrees) 90.000 Scan frame (CEL or S/C): S/C Length Offset (arc-sec): 0.2000 Width Offset (arc-sec): ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 2 Exposure Logsheet lines: 22.00 FGS Scan: DWELL Dwell Only: dwell points/line: 7 Seconds per dwell: 1.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 0.4000 Angle between sides (degrees) 0.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0000 PA of first scan line (degrees) 90.000 Scan frame (CEL or S/C): S/C Length Offset (arc-sec): 0.2000 Width Offset (arc-sec): ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 3 Exposure Logsheet lines: 32.00 FGS Scan: DWELL Dwell Only: dwell points/line: 7 Seconds per dwell: 1.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 0.4000 Angle between sides (degrees) 0.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0000 PA of first scan line (degrees) 90.000 Scan frame (CEL or S/C): S/C Length Offset (arc-sec): 0.2000 Width Offset (arc-sec): ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 4 Exposure Logsheet lines: 42.00 FGS Scan: DWELL Dwell Only: dwell points/line: 7 Seconds per dwell: 1.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 0.4000 Angle between sides (degrees) 0.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0000 PA of first scan line (degrees) 90.000 Scan frame (CEL or S/C): S/C Length Offset (arc-sec): 0.2000 Width Offset (arc-sec): ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4550c [ 10] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/BINARY ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FAINT=940.0 BRIGHT=33000.0 TYPE=UP FAINT=660.0 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 13.28 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category MASSIVE STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 3/11.00-15.00; GROUP 11.00-15.00 NO GAP; ONBOARD ACQ FOR 12.00; ONBOARD ACQ FOR 13.00; SPATIAL SCAN; CYCLE 3/21.00-25.00; GROUP 21.00-25.00 NO GAP; ONBOARD ACQ FOR 22.00; ONBOARD ACQ FOR 23.00; CYCLE 3/31.00-35.00; GROUP 31.00-35.00 NO GAP; ONBOARD ACQ FOR 32.00; ONBOARD ACQ FOR 33.00; CYCLE 3/41.00-45.00; GROUP 41.00-45.00 NO GAP; ONBOARD ACQ FOR 42.00; ONBOARD ACQ FOR 43.00; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G130H G190H G270H ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD32402 WS6 BR10 HD37026 WS31 BR43 HD37680 WS35 BR50 HD32257 WS4 BR8 ------------------------------------------------------------------------------------------------------------------------------------