12179( 2) - 08-Jul-2010 18:06:42 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12179 Version: 2 Check-in Time: 08-Jul-2010 18:06:42 STScI Edit Number: 0 Title The Stellar Winds of Evolved, Braked O-Type Magnetic Oblique Rotators ------------------------------------------------------------------------------------ Type Cycle GO 18 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jean-Claude Bouret CNRS, Laboratoire d'Astrophysique de Marseille CoI: Dr. Nolan R. Walborn Space Telescope Science Institute Y CoI: Dr. Fabrice Martins Universite de Montepellier II N CoI: Dr. Yael Naze Universite de Liege N CoI: Dr. Ian D. Howarth University College London N CoI: Dr. Alexander W. Fullerton Space Telescope Science Institute N CoI: Dr. Gregg A. Wade Royal Military College of Canada N CoI: Dr. Artemio Herrero Instituto de Astrofisica de Canarias N CoI: Dr. Wagner Marcolino Observatorio Nacional N ------------------------------------------------------------------------------------ Abstract Magnetic fields have recently been discovered on several massive stars, but their origin and influence on the evolution of these stars are poorly understood. Two of these objects, HD 191612 and HD 108, are of particular interest. Very recent spectropolarimetric observations have shown that they are most likely magnetic oblique rotators, like the young O star Theta1 Ori C, whose 15d periodically variable field was found somewhat earlier. However, the two new objects are much slower rotators, unusually so for O stars, with periods of 538d and 50-60yrs, respectively, and there are other indications that they are older. They provide an opportunity to study the efficiency of wind braking of magnetic O stars through angular momentum loss. We shall perform STIS high-resolution UV spectroscopy of HD 191612 and HD 108 (phase resolved for the former) to derive more complete estimates of fundamental quantities than available from optical data alone. We shall measure the mass-loss rates from the UV wind profiles, which will constrain the extreme wind confinement of these stars and establish whether the large H-alpha emission variations are wind-related or geometrical. We shall also derive more accurate ages and stellar surface properties. In turn, these results will support a more definitive discussion of the angular momentum evolution versus the ages of HD 191612 and HD 108, and of the comparison with the younger and faster Theta1 Ori C. ------------------------------------------------------------------------------------ Observations Description ------------------------ These are straightforward spectroscopic observations, for which the STIS E140M and E230M echelles are the configurations of choice, providing complete FUV and NUV spectral coverage at high resolution and S/N within a single orbit. The FUV contains the high-priority stellar-wind resonance lines of N~V, Si~IV, and C~IV, as well as weaker subordinate, metastable wind lines of He~II and N~IV. The NUV adds several He absorption lines that are useful photospheric diagnostics, to compare with those in the optical. 12179( 2) - 08-Jul-2010 18:06:42 - [ 2] At the declination of HD~191612, the visibility period is 55~min. Guide-star and target acquisitions consume 6~min each; no ACQ-PEAK is required with the 0.2~arcsec square aperture that we shall use. The instrument overheads are 16~min. Thus, 27~min are available for spectroscopic exposures, which is more than ample for our target and configurations. For an O8 spectral type and S/N of 40, the STIS ETC gives exposure times of 600 and 100~sec for E140M and E230M, respectively. Depending on the Phase~II overheads, we may do two exposures in each configuration to increase the data quality. Our target is safe for observation in the above configurations per the ETC. For HD~108 the visibility period is 59~min. Acquisitions and instrument overheads are as above, except that this star is too bright for E230M with the 0.2X0.2 aperture, so we shall have to use the 0.1X0.03 that requires a two-stage peakup, adding 12~min to the overheads. Still, 19~min are left for scientific exposures, which are just 300~sec in the FUV and 100~sec in the NUV. Again, the exposure times may be increased, or two exposures obtained in each region. Both stars are isolated from any other bright stars, so there will be no field safety concerns. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12179( 2) - 08-Jul-2010 18:06:42 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD191612 STAR, CIRCUMSTELLAR RA=20H09M28.6102S +/- 0.1", J2000 V = 7.78 E(B-V)=0.58, SpT=O6f?p-O8fp MATTER, DISK, EMISSION DEC=+35D44'1.29" +/- 0.1" LINE STAR, OF, WIND Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 2 HD108 STAR, CIRCUMSTELLAR RA=00H06M3.3861S +/- 0.1", J2000 V = 7.38 E(B-V)=0.49, SpT=O6f?p-O8fp MATTER, DISK, EMISSION DEC=+63D40'46.76" +/- 0.1" LINE STAR, OF, WIND Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 12179( 2) - 08-Jul-2010 18:06:42 - [ 4] Visit: 01 Visit Requirements: BETWEEN 20-AUG-2010:00:00:00 AND 26-AUG-2010:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD191612 STIS/CCD ACQ F28X50OII MIRROR 1 0.2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD191612 STIS/FUV ACCUM 0.2X0.2 E140M 1425 2 750 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 3 HD191612 STIS/NUV ACCUM 0.2X0.2 E230M 2707 2 150 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD191612 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A I HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 1 none 1 N/A -MAMA HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 2 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 1 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 2 none 1 N/A -MAMA 12179( 2) - 08-Jul-2010 18:06:42 - [ 5] Visit: 02 Visit Requirements: BETWEEN 01-JAN-2011:00:00:00 AND 07-JAN-2011:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD191612 STIS/CCD ACQ F28X50OII MIRROR 1 0.2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD191612 STIS/FUV ACCUM 0.2X0.2 E140M 1425 2 750 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 3 HD191612 STIS/NUV ACCUM 0.2X0.2 E230M 2707 2 150 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD191612 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A I HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 1 none 1 N/A -MAMA HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 2 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 1 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 2 none 1 N/A -MAMA 12179( 2) - 08-Jul-2010 18:06:42 - [ 6] Visit: 03 Visit Requirements: BETWEEN 16-MAY-2011:00:00:00 AND 22-MAY-2011:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD191612 STIS/CCD ACQ F28X50OII MIRROR 1 0.2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD191612 STIS/FUV ACCUM 0.2X0.2 E140M 1425 2 750 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 3 HD191612 STIS/NUV ACCUM 0.2X0.2 E230M 2707 2 150 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD191612 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A I HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 1 none 1 N/A -MAMA HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 2 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 1 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 2 none 1 N/A -MAMA 12179( 2) - 08-Jul-2010 18:06:42 - [ 7] Visit: 04 Visit Requirements: BETWEEN 27-SEP-2011:00:00:00 AND 03-OCT-2011:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD191612 STIS/CCD ACQ F28X50OII MIRROR 1 0.2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD191612 STIS/FUV ACCUM 0.2X0.2 E140M 1425 2 750 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 3 HD191612 STIS/NUV ACCUM 0.2X0.2 E230M 2707 2 150 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD191612 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A I HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 1 none 1 N/A -MAMA HD191612 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 2 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 1 none 1 N/A -MAMA HD191612 3 STIS/NUV ACCUM 0.2X0.2 E230M 2707 none none 2 none 1 N/A -MAMA 12179( 2) - 08-Jul-2010 18:06:42 - [ 8] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD108 STIS/CCD ACQ F28X50OII MIRROR 1 0.2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD108 STIS/FUV ACCUM 0.2X0.2 E140M 1425 2 350 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 3 HD108 STIS/CCD ACQ/PEA 0.2X0.09 G430M 4451 1 0.2 S K ------------------------------------------------------------------------------------------------------------------------------------ 4 HD108 STIS/CCD ACQ/PEA 0.1X0.03 G430M 4451 1 1.0 S K ------------------------------------------------------------------------------------------------------------------------------------ 5 HD108 STIS/NUV ACCUM 0.1X0.03 E230M 2707 2 150 S -MAMA ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD108 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A I HD108 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 1 none 1 N/A -MAMA HD108 2 STIS/FUV ACCUM 0.2X0.2 E140M 1425 none none 2 none 1 N/A -MAMA HD108 3 STIS/CCD ACQ/PEA 0.2X0.09 G430M 4451 none none none none 1 N/A K HD108 4 STIS/CCD ACQ/PEA 0.1X0.03 G430M 4451 none none none none 1 N/A K HD108 5 STIS/NUV ACCUM 0.1X0.03 E230M 2707 none none 1 none 1 N/A -MAMA HD108 5 STIS/NUV ACCUM 0.1X0.03 E230M 2707 none none 2 none 1 N/A -MAMA 12179( 2) - 08-Jul-2010 18:06:42 - [ 9] Summary Form for Proposal 12179 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 0.1X0.03, 0.2X0.09, 0.2X0.2, F28X50OII ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/PEAK ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-JAN-2011:00:00:00 AND 07-JAN-2011:00:00:00, BETWEEN 16-MAY-2011:00:00:00 AND 22-MAY-2011:00:00:00, BETWEEN 20-AUG-2010:00:00:00 AND 26-AUG-2010:00:00:00, BETWEEN 27-SEP-2011:00:00:00 AND 03-OCT-2011:00:00:00 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements E140M, E230M, G430M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD108, HD191612 ------------------------------------------------------------------------------------------------------------------------------------