6515( 3) - 02/05/96 12:30 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6515 Version: 3 Check-in Date: 05-Feb-1996 11:57:39 1.Proposal Title: UNRAVELLING THE COMPLEX WIND FROM Zeta AURIGAE : CYCLE 6 PORTION ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle COOL STARS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Alexander Brown University of Colorado CoI: Jeffrey Linsky University of Colorado N CoI: Rolf Walder ETH-Zentrum N CoI: Kevin Marshall IOA, Cambridge University N CoI: Robert Baade Hamburger Sternwarte N CoI: Kirsch Thomas Hamburger Sternwarte N CoI: Dieter Reimers Hamburger Sternwarte N CoI: Graham Harper University of Colorado N CoI: Philip Bennett University of Colorado N ------------------------------------------------------------------------------------ 6. Abstract Zeta Aur is a long period (972 day) binary containing a K supergiant and a B dwarf. In Cycle 2 we observed with the GHRS the last eclipse of the B dwarf by the K star's wind and chromosphere. Analysis of these spectra has led to a significantly improved understanding of how the K star wind flows from the binary system. A low density region forms in front of the binary system which periodically becomes an H II region as the B star moves in front of the K star, and the wind shows much lower turbulence velocities than previously inferred from IUE data. Unfortunately the HST data have also emphasised just how complex this process really is and the high degree of asymmetry involved. The wind outflow and orbital velocity are comparable and this leads to accelerated and stagnant zones in the flow, which is itself modulated by the varying separation of the two stars. The proposed observations form part of our previously approved Cycle 5/6 program to study Zeta Aur during the next eclipse centered on December 1 1995, and will provide new observations to help answer some of the questions raised as a result of our analysis and modelling. Our objectives are to (1) measure the turbulence, T_e, and N_e of the K star chromosphere during eclipse, (2) determine the stability of the system from orbit- to-orbit, (3) investigate the symmetry of the K star atmosphere, (4) determine the ISM column density and reddening, and (5) measure the ionization fraction of doubly- ionized metals and the turbulence in the K star wind. ------------------------------------------------------------------------------------ 6515( 3) - 02/05/96 12:30 - [ 2] Observations Description ------------------------ Zeta Aurigae is a spectroscopic binary and is not resolved. The observing requirements for the Cycle 6 observations have been fully tested using the Cycle 5 RPS Phase 2 proposal software. We will acquire with the N1 mirror. The echelle observations will be obtained with the SSA to maximize spectral resolution, while the first order gratings will use the LSA to maximise throughput and photometric accuracy. FP-SPLITs will be used for the echelle and G160M exposure to reduce fixed pattern noise. WAVECAL exposures are included before the Echelle and radial velocity exposures to ensure maximum accuracy in the wavelength scale. The sub-exposures will be limited to a maximum of 5 minutes to avoid geomagnetic effects (GIMP). The total project requires 15 orbits: Cycle 5 (12 orbits scheduled) + Cycle 6 (3 orbits). underlineCycle 6 (Phase 0.265): This phase samples a portion of the orbit when the B star lies in front of the K star, in a region of low circumstellar column. No GHRS spectra exist for this part of the orbit. This phase allows separation of circumstellar and interstellar effects. We shall measure the interstellar Cl I 1347.24 A line. We will first make a WAVECAL and then use the Echelle-A to obtain maximum velocity information. A full range of circumstellar singly and doubly ionized species will be sampled. This information cannot be obtained in Cycle 5. __________________________________________________________________ TABLE 1 PROPOSED OBSERVATIONS Mode/Aper Wavelength Exposure S/N Diagnostic Features Range (A) (s) __________________________________________________________________ Epoch 10 (Phi = 0.265) 3 Orbits ECH-A 1345--1353 762 45 Cl I UV 2, IS and wind lines ECH -A 1248--1254 544 40 S II and S I (ionization) ECH-A 1666--1674 544 45 Al II 1670 G160M 1525--1551 544 45 Si II UV 2, C IV UV 1 G140L 1150--1436 136 100 Rayleigh scattering in wind ECH-B 1853--1863 435 40 Al III UV1 G160M 1172--1209 544 30 Si II UV 5, B star RV G200M 1890--1928 326 50 Fe III uv34, Si III, C III, S I _________________________________________________________________ The observations are time critical and must be obtained at specific phases of the orbit of Zeta Aur. Table 2 gives the dates of the proposed phases and the acceptable range of days about the corresponding phase. ______________________________________________________________ TABLE 2 DATES OF PROPOSED OBSERVATIONS ______________________________________________________________ Phase Cycle Date Tolerance 0.957 5 16-OCT-95 +/- 2 days 0.000 5 01-DEC-95 +/- 7 days 0.045 5 13- JAN-96 +/- 2 days 0.265 6 14-AUG-96 +/- 7 days ______________________________________________________________ Real Time Justification ----------------------- None Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6515( 3) - 02/05/96 12:30 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Center for Astrophysics and Space*Astronomy, Campus Box 389,*Boulder, CO 80309-0389 Ship Via: UPS Email: PI_Address , ------------------------------------------------------------------------------------ 6515( 3) - 02/05/96 12:30 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD32068 STAR, K III-I RA=05H 02M 28.685S +/- 0.01S, 2000 V = V = 3.74+/-0.08 DEC=+41D 04' 32.96" +/- 0.03" +12.8 B-V = +1.26+/-0.13 TYPE=K4II Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0009 -0.022 0.003 6515( 3) - 02/05/96 12:30 - [ 5] Visit: 01 Visit Requirements: BETWEEN 06-AUG-96 AND 22-AUG-96 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 ------------------------------------------------------------------------------------------------------------------------------------ 401 HD32068 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,S 1 1.8S ONBOARD ACQ FOR 402 EARCH-SIZE=3 Comments: STEP-TIME = 0.2 SEC (approx 60,000 cts in STEP-TIME) ------------------------------------------------------------------------------------------------------------------------------------ 402 HD32068 HRS ACQ/PEA 0.25 MIRROR-N1 SEARCH-SIZE=5 1 5S ONBOARD ACQ FOR 425-490 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 425 HD32068 HRS ACCUM 0.25 ECH-A 1251 COMB=FOUR,STEP- 1 544.0S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 428 WAVE HRS ACCUM SC2 ECH-A 1349 COMB=FOUR,STEP- 1 64.0S PATT=3,DOPPLER= OFF Comments: CALIB FOR 430 ------------------------------------------------------------------------------------------------------------------------------------ 430 HD32068 HRS ACCUM 0.25 ECH-A 1349 COMB=FOUR,STEP- 1 761.6S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 438 WAVE HRS ACCUM SC2 ECH-A 1669.5 COMB=FOUR,STEP- 1 64.0S PATT=3,DOPPLER= OFF Comments: CALIB FOR 440 ------------------------------------------------------------------------------------------------------------------------------------ 440 HD32068 HRS ACCUM 0.25 ECH-A 1669.5 COMB=FOUR,STEP- 1 544.0S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 445 HD32068 HRS ACCUM 2.0 G140M 1538 COMB=FOUR,STEP- 1 544.0S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 450 HD32068 HRS ACCUM 2.0 G140L 1293 COMB=FOUR,STEP- 1 136.0S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 6515( 3) - 02/05/96 12:30 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 465 WAVE HRS ACCUM SC2 ECH-B 1858.8 COMB=FOUR,STEP- 1 64.0S PATT=3,DOPPLER= OFF Comments: CALIB FOR 470 ------------------------------------------------------------------------------------------------------------------------------------ 470 HD32068 HRS ACCUM 0.25 ECH-B 1858.8 COMB=FOUR,STEP- 1 435.2S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 475 HD32068 HRS ACCUM 2.0 G160M 1190 COMB=FOUR,STEP- 1 544.0S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 490 HD32068 HRS ACCUM 2.0 G200M 1909 COMB=FOUR,STEP- 1 326.4S PATT=DEF,DOPPLE R=DEF,FP- SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 6515( 3) - 02/05/96 12:30 - [ 7] Summary Form for Proposal 6515 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN SEARCH-SIZE=3 SEARCH-SIZE=5 FP-SPLIT=STD DOPPLER=OFF DOPPLER=DEF STEP-PATT=3 STEP-PATT=DEF COMB=FOUR FP-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category COOL STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 06-AUG-96 AND 22-AUG-96 ONBOARD ACQ FOR 402 ONBOARD ACQ FOR 425-490 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N1 ECH-A G140M G140L ECH-B G160M G200M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD32068 WAVE ------------------------------------------------------------------------------------------------------------------------------------