9237( 4) - 02/12/02 08:48 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9237 Version: 4 Check-in Date: 12-Feb-2002 08:46:36 1.Proposal Title: The Masses of the O-type Binary 15 Monocerotis ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 10 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Douglas Gies Georgia State University Research Foundation CoI: Dr. William Bagnuolo Jr. Georgia State University N CoI: Dr. William Hartkopf U.S. Naval Observatory N CoI: Dr. Brian Mason U.S. Naval Observatory N CoI: Dr. Harold McAlister Georgia State University N CoI: Dr. Edmund Nelan Space Telescope Science Institute N CoI: Ms. Debra Wallace Georgia State University N ------------------------------------------------------------------------------------ 5. Abstract The O-type star 15 Mon (HD 47839) was recently discovered to be an astrometric and spectroscopic binary with an orbital period of 25 years; it is the first known O- star system to bridge the observational gap between the period regimes normally probed by these techniques. An analysis of both the radial velocity curve and astrometric orbit yields the masses of the components and distance to the system. Both radial velocity and astrometric measurements are scant at present, but the system is now close to periastron and continued spectroscopic and astrometric monitoring will lead to a definitive orbit and yield important information about the masses of O-type stars. FGS TRANS mode measurements of separation, position angle, and magnitude difference (begun in Cycle 5) are needed to bridge the gap between recent speckle observations and anticipated observations with CHARA Array optical interferometer. In addition, new field astrometry measurements (FGS POS mode) will provide the proper motion, parallax, and the binary motion around the center of mass. The POS data will provide an accurate estimate of the mass ratio and an improved estimate of distance, and taken together with the spectroscopic and astrometric orbital data, we should be able to obtain masses for both components accurate to a few percent. ------------------------------------------------------------------------------------ 9237( 4) - 02/12/02 08:48 - [ 2] Observations Description ------------------------ We are seeking time to continue and expand a long term program which was approved for 2 orbits in each of Cycles 5, 6, 7, and 8. Our first goal is to obtain FGS TRANS mode measurements of the separation, position angle, and magnitude difference of 15 Mon twice each year (see Fig. 3). We are aiming for a positional accuracy of ~ 1 mas and a photometric accuracy of 0.1 mag, both of which have been achieved in recent binary studies with the FGS (see Franz et al. 1998, AJ, 116, 1432). Our second goal is to obtain complementary POS mode observations of nearby reference stars so that we can determine the proper motion, parallax, and stellar orbital motion around the system barycenter. We need two visits each year near the times of maximum parallax shift. We plan to begin these POS mode observations during time already granted the project in Cycle 8. Because of the relative brightness of the star, the observations will be made with the 5 mag neutral density filter, F5ND. We plan to obtain approximately 17 scans in the TRANS mode of operation which should require approximately 18 minutes exposure time. The remaining 17 minutes in the orbit will be used for POS mode observations. The success of the Cycle 5, 6, and 7 observations demonstrate the general feasibility of the project (see above). We also need scans of the calibration target, Mu Col, but we understand that plans exist for the Observatory to obtain these on a routine basis through future Cycles. Real Time Justification ----------------------- The observations need to be scheduled near the times of maximum parallax shift (early April and early October). Our group (plus collaborators) is continuing a program of high S/N spectroscopy of 15 Mon to derive an accurate radial velocity curve and to study the profile changes (since the line profiles of both components are visible in the spectrum). We are obtaining spectra primarily with our Multi-Telescope Telescope (at the GSU Hard Labor Creek Observatory near Atlanta), a 1-m equivalent aperture telescope with a fiber-fed spectrograph and CCD detector. Calibration Justification ------------------------- See "Observing_Description" section above. Additional Comments ------------------- ------------------------------------------------------------------------------------ 9237( 4) - 02/12/02 08:48 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD47839 STAR, MAIN SEQUENCE O, RA=06H 40M 58.66104S +/- J2000 V = 22.0 V = 4.65+/-0.02 STAR 0.00005S, DEC=09D 53' 44.737" +/ B-V = -0.25+/-0.02 - 0.005" TYPE=O7V((F)) Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Comments: LONG PERIOD BINARY, 15-MON. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.00004 -0.0025 0.001 3 REF1 STAR, CALIBRATION, RA=100.2579292D +/- 0.0002D, J2000 V = 8.710+/-0.2 ASTROMETRIC DEC=9.8803200D +/- 0.002D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG Comments: Reference star for 15 Mon 4 REF2 STAR, CALIBRATION, RA=100.3186292D +/- 0.001D, J2000 V = 12.650+/-0.1 ASTROMETRIC DEC=9.8705000D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 5 REF3 STAR, CALIBRATION, RA=100.1721292D +/- 0.001D, J2000 V = 13.560+/-0.1 ASTROMETRIC DEC=9.9040500D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 6 REF4 STAR, CALIBRATION, RA=100.3022583D +/- 0.001D, J2000 V = 13.740+/-0.1 ASTROMETRIC DEC=9.8755300D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 7 REF5 STAR, CALIBRATION, RA=100.2945417D +/- 0.001D, J2000 V = 8.460+/-0.1 ASTROMETRIC DEC=9.8832900D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 8 REF6 STAR, CALIBRATION, RA=100.2062292D +/- 0.001D, J2000 V = 11.38+/-0.1 ASTROMETRIC DEC=9.8898400D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 9 REF7 STAR, CALIBRATION, RA=100.2951583D +/- 0.001D, J2000 V = 8.490+/-0.1 ASTROMETRIC DEC=9.8829400D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 10 REF8 STAR, CALIBRATION, RA=100.2688792D +/- 0.001D, J2000 V = 10.36+/-0.1 ASTROMETRIC DEC=9.9122800D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 11 REF9 STAR, CALIBRATION, RA=100.2681917D +/- 0.001D, J2000 V = 12.070+/-0.1 ASTROMETRIC DEC=9.8640600D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 12 REF10 STAR, CALIBRATION, RA=100.2470583D +/- 0.001D, J2000 V = 12.4+/-0.1 ASTROMETRIC DEC=9.9223900D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 13 REF11 STAR, CALIBRATION, RA=100.2500083D +/- 0.001D, J2000 V = 9.880+/-0.1 ASTROMETRIC DEC=9.8717100D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 9237( 4) - 02/12/02 08:48 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 14 REF12 STAR, CALIBRATION, RA=100.2590292D +/- 0.001D, J2000 V = 12.840+/-0.1 ASTROMETRIC DEC=9.8645900D +/- 0.001D, PLATE -ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 15 REF13 STAR, CALIBRATION, RA=06H 41M 11.2S +/- 1", DEC=09D J2000 V = 8.7+/-0.1 ASTROMETRIC 52' 54.0" +/- 1", PLATE-ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 16 REF14 STAR, CALIBRATION, RA=06H 41M 10.2S +/- 1", DEC=09D J2000 V = 8.7+/-0.1 ASTROMETRIC 53' 2.0" +/- 1", PLATE-ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 17 REF15 STAR, CALIBRATION, RA=06H 40M 56.4S +/- 1", DEC=09D J2000 V = 12.400+/-0.1 ASTROMETRIC 54' 7.5" +/- 1", PLATE-ID=03QQ Coordinate Source: GUIDE_STAR_CATALOG 30 HD38666 STAR, MAIN SEQUENCE O, RA=05H 45M 59.89293S +/- J2000 V = 109. V = 5.17+/-0.02 CALIBRATION, 0.00003S, DEC=-32D 18' 22.9679" B-V = -0.28+/-0.02 ASTROMETRIC, POINT +/- 0.0004" TYPE=O9.5V SPREAD FUNCTION, FGS Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Comments: Mu-COL. CALIBRATION TARGET, COORDINATES ARE FROM THE HIPPARCOS CATALOGUE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.00024 -0.0226 0.0025 9237( 4) - 02/12/02 08:48 - [ 5] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 05-Oct-2001 AND 15-Oct-2001 ORIENT 283D TO 288D SCHED 60% 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 HD47839 FGS TRANS 1 F5ND SCANS=25,STEP-SIZE=1.0 1 500 S POS TARG 0, 0 SEQ 10-210 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 30 REF15 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 40 REF11 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 50 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 60 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 70 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 80 REF15 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 90 REF2 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 100 REF4 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 110 REF13 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 120 REF14 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 130 REF11 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 140 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 150 REF8 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 160 REF10 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 170 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 180 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 190 REF11 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 200 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 210 REF15 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 9237( 4) - 02/12/02 08:48 - [ 6] Visit: 02 Visit Priority: Visit Requirements: BETWEEN 01-Apr-2002 AND 15-Apr-2002 ORIENT 95.0D TO 98.0D SCHED 60% 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 HD47839 FGS TRANS 1 F5ND SCANS=15,STEP-SIZE=0.5 1 450 S POS TARG 0, 0 SEQ 10-210 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 30 REF15 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 40 REF11 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 50 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 60 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 70 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 80 REF15 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 90 REF2 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 100 REF4 FGS TRANS 1 F583W STEP-SIZE=0.5,SCANS=3 1 100 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 110 REF13 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 120 REF14 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 130 REF11 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 140 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 150 REF8 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 160 REF10 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 170 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 180 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 190 REF11 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 200 HD47839 FGS POS 1 F5ND 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 210 REF15 FGS POS 1 F583W 1 10 S SAME POS AS 10 ------------------------------------------------------------------------------------------------------------------------------------ 9237( 4) - 02/12/02 08:48 - [ 7] Summary Form for Proposal 9237 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations FGS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes TRANS POS ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCANS=25 STEP-SIZE=1.0 STEP-SIZE=0.5 SCANS=3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 05-Oct-2001 AND 15-Oct-2001 ORIENT 283D TO 288D SCHED 60% POS TARG 0, 0 SEQ 10-210 NON-INT SAME POS AS 10 BETWEEN 01-Apr-2002 AND 15-Apr-2002 ORIENT 95.0D TO 98.0D SCHED 60% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F5ND F583W ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD47839 REF15 REF11 REF6 REF3 REF2 REF4 REF13 REF14 REF8 REF10 ------------------------------------------------------------------------------------------------------------------------------------