8204( 4) - 08/12/99 07:34 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8204 Version: 4 Check-in Date: 13-Apr-1999 11:23:30 1.Proposal Title: Calibration of the Wind Momentum-- Luminosity Relationship in Cyg OB2 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Artemio Herrero Instituto de Astrofisica de Canarias CoI: Dr Stephen J. Smartt Isaac Newton Group, La Palma N CoI: Dr Luis J. Corral Instituto de Astrofisica de Canarias N CoI: M. Rosario Villamariz Instituto de Astrofisica de Canarias N CoI: Dr. Eduardo L. Martin University of California N CoI: Prof. Rolf--Peter Kudritzki Universitaets-Sternwarte Munich N CoI: Dr Joachim Puls Universitaets-Sternwarte Munich N CoI: Dr Daniel J. Lennon Isaac Newton Group, La Palma N ------------------------------------------------------------------------------------ 5. Abstract We propose to improve the calibration of the Wind momentum -- Luminosity Relationship of hot stars at solar metallicity by adding new objects with well determined distances, stellar parameters and wind momenta. We propose to acquire STIS low- resolution FUV spectra of O- and B-supergiants belonging to the same OB association to determine their terminal wind velocities. We selected stars in Cyg OB2, for which we alredy have optical observations and have performed analyses (or which are currently under way) with our model atmospheres codes to determine their stellar parameters and mass loss rates. A precise calibration of the WLR using objects of the solar neighbourhood is crucial for future applications of the method to determine extragalactic distances out the Virgo and Fornax clusters of galaxies. ------------------------------------------------------------------------------------ 8204( 4) - 08/12/99 07:34 - [ 2] Observations Description ------------------------ The targets have spectral types between O3 and B1. The resolution of the G140L grating of 300 km s^-1 is adequate to measure the terminal velocities of the winds, that are expected to lie between 1000 and 3000 km s^-1 (see Haser, 1995, Haser et al., 1995, 1998). The spectral region covered includes the resonance lines of CIV, SiIV and NV that are usually used for the purpose of terminal velocity measurements. The S/N ratios required are between 30 and 40. We have used magnitudes and individual values of E(B-V) published by Massey and Thompson (1991), and have estimated the exposure times using the STIS Exposure Time Calculator on the WWW. The total number of orbits was determined taking into account GS ACQ and Targ ACQ times of 6 minutes each on the first orbit and 5 minutes for the GS Reaq on each subsequent orbit. No PEAKup procedure is needed because we plan to use slits wider than 0.1 arcsecond. Real Time Justification ----------------------- The targets have been observed in the optical (blue and H_Alpha regions) with intermediate spectral resolution and high S/N ratios. Many of the objects have been already analyzed by means of plane--parallel, hydrostatic NLTE model atmospheres, and gravities, effective tempetarures, helium abundances, radii and luminosities have been derived. Further analysis with our spherical, NLTE, mass losing code to derive mass loss rates from H_Alpha are currently under way. Thus, only the terminal velocities will be required to calibrate the WLR in Cyg OB2. Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8204( 4) - 08/12/99 07:34 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CYGOB2-2 STAR, B0-B2 III-I RA=20H 31M 22.03S +/- 0.2", J2000 V = 10.64+/-0.01 DEC=41D 31' 28.2" +/- 0.2", B-V = 1.18+/-0.02 PLATE-ID=00VV E(B-V) = 1.37+/-0.02 TYPE=B1I 2 CYGOB2-7 STAR, SUPERGIANT O, OF RA=20H 33M 14.11S +/- 0.2", J2000 V = 10.55+/-0.01 DEC=41D 20' 22.0" +/- 0.2", B-V = 1.45+/-0.02 PLATE-ID=00VV E(B-V) = 1.76+/-0.02 TYPE=O3IF 3 CYGOB2-8C STAR, SUPERGIANT O, OF RA=20H 33M 17.98S +/- 0.4", J2000 V = 10.19+/-0.01 DEC=41D 18' 30.9" +/- 0.4", B-V = 1.24+/-0.02 PLATE-ID=00VV E(B-V) = 1.54+/-0.02 TYPE=O5IF 4 CYGOB2-10 STAR, SUPERGIANT O RA=20H 33M 46.11S +/- 0.2", J2000 V = 9.88+/-0.01 DEC=41D 33' 1.0" +/- 0.2", PLATE B-V = 1.59+/-0.02 -ID=00VV E(B-V) = 1.86+/-0.02 TYPE=O9.5I 5 CYGOB2-11 STAR, SUPERGIANT O, OF RA=20H 34M 8.50S +/- 0.2", J2000 V = 10.03+/-0.01 DEC=41D 36' 59.4" +/- 0.2", E(B-V) = 1.79+/-0.02 PLATE-ID=00VV B-V = 1.49+/-0.02 TYPE=O5IF+ 6 CYGOB2-4 STAR, GIANT O, OF RA=20H 32M 13.82S +/- 0.2", J2000 V = 10.23+/-0.01 DEC=41D 27' 12.3" +/- 0.2", B-V = 1.19+/-0.02 PLATE-ID=00VV E(B-V) = 1.50+/-0.02 TYPE=O7III((F)) 7 CYGOB2-8A STAR, SUPERGIANT O, OF RA=20H 33M 15.08S +/- 0.002", J2000 V = 9.14+/-0.01 DEC=41D 18' 50.5" +/- 0.002" B-V = 1.30+/-0.02 E(B-V) = 1.60+/-0.02 TYPE=O5.5I(F) Comments: coordinates taken from Hipparcos output catalogue GSC coordinates for GSC 3161-01325 are actually for the blend Cyg OB2 8A+8B Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B1991.25 0.0 0.0 0.0 8204( 4) - 08/12/99 07:34 - [ 4] Visit: 01 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 CYGOB2-2 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 11, 12 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 CYGOB2-2 STIS/F ACCUM 52X0.2 G140L 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 12 CYGOB2-2 STIS/F ACCUM 52X0.2 G140L 1425 1 2900 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 20 CYGOB2-4 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 21 CD P ------------------------------------------------------------------------------------------------------------------------------------ 21 CYGOB2-4 STIS/F ACCUM 52X0.2 G140L 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 CYGOB2-7 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 31, 32 CD P ------------------------------------------------------------------------------------------------------------------------------------ 31 CYGOB2-7 STIS/F ACCUM 52X0.2 G140L 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 32 CYGOB2-7 STIS/F ACCUM 52X0.2 G140L 1425 1 2900 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8204( 4) - 08/12/99 07:34 - [ 5] Visit: 02 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 40 CYGOB2-8A STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.4 S ONBOARD ACQ FOR 41 CD III ------------------------------------------------------------------------------------------------------------------------------------ 41 CYGOB2-8A STIS/F ACCUM 52X0.2 G140L 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 CYGOB2-11 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 51, 52 CD P ------------------------------------------------------------------------------------------------------------------------------------ 51 CYGOB2-11 STIS/F ACCUM 52X0.2 G140L 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 52 CYGOB2-11 STIS/F ACCUM 52X0.2 G140L 1425 1 2900 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8204( 4) - 08/12/99 07:34 - [ 6] Visit: 03 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 60 CYGOB2-8C STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 61 CD P ------------------------------------------------------------------------------------------------------------------------------------ 61 CYGOB2-8C STIS/F ACCUM 52X0.2 G140L 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 70 CYGOB2-10 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 71, 72 CD P ------------------------------------------------------------------------------------------------------------------------------------ 71 CYGOB2-10 STIS/F ACCUM 52X0.2 G140L 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 72 CYGOB2-10 STIS/F ACCUM 52X0.2 G140L 1425 1 2900 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8204( 4) - 08/12/99 07:34 - [ 7] Summary Form for Proposal 8204 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.2 F28X50OIII ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 11, 12 ONBOARD ACQ FOR 21 ONBOARD ACQ FOR 31, 32 ONBOARD ACQ FOR 41 ONBOARD ACQ FOR 51, 52 ONBOARD ACQ FOR 61 ONBOARD ACQ FOR 71, 72 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names CYGOB2-2 CYGOB2-4 CYGOB2-7 CYGOB2-8A CYGOB2-11 CYGOB2-8C CYGOB2-10 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 ------------------------------------------------------------------------------------------------------------------------------------