6493( 7) - 04/17/96 13:32 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6493 Version: 7 Check-in Date: 17-Apr-1996 13:27:47 1.Proposal Title: Accretion in the Interacting Binary UX Monocerotis ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle BINARIES AND STAR FOR GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Mirek Plavec University of California CoI: Ivan Hubeny USRA, NASA Goddard Space Flight Center, N Greenbelt CoI: Charles Keyes Space Telescope Science Institute N CoI: Geraldine Peters University of Southern California, Los N Angeles CoI: Steven Shore Indiana University at South Bend N ------------------------------------------------------------------------------------ 6. Abstract We plan to use the GHRS spectrograph in order to obtain high-S/N UV spectra in two segments at three orbital phases of the interacting binary UX Monocerotis. This system is an intermediate case between the weakly interacting ordinary Algols and the strongly interacting W Serpentis systems (``hyperactive Algols''). This means that the rate of mass transfer is rather high to produce observable effects, yet the component stars are not completely obscured by the circumstellar matter, so that the fundamental parameters of the binary system are known. As such, UX Mon offers a rare opportunity to study mass transfer processes in interacting binaries: the mass- transfering stream, the impact region on the gainer, the ``splashed'' disk, and the outflowing stream or induced wind. These phenomena can be studied by analyzing and modeling suitably selected emission (and absorption) lines observed from different points of view, i.e. at several orbital phases. A recent study of W Serpentis suggests two emitting regions: the impact area and the disk boundary layer. In UX Mon, we can study these regions much more quantitatively, since the system parameters are much better defined and known. For analysis and modeling we have excellent programs, considerable experience, and extensive supporting data, photometric as well as spectroscopic. ------------------------------------------------------------------------------------ 6493( 7) - 04/17/96 13:32 - [ 2] Observations Description ------------------------ We plan to observe UX Mon with the GHRS LSA and the G160M grating in two regions centered at 1400 Angstrom (Si IV), and 1540 Angstrom (C IV, Si II), at 0.07 Angstrom spectral resolution. We will achieve a S/N of 25 or better per diode in each spectral range. These observations should be executed three times at different orbital phases. It is essential, if at all possible, to execute all observations within the same orbital cycle of 5.9 days. The observing sequence in each visit will be identical and will utilize a total exposure time of 38 minutes at the 1400 Angstrom setting, and a single 20 minute ACCUM at the 1540 Angstrom setting. Given the UX Mon 52-minute visibility period, HRS ACCUM overheads, and the GIM-related 20-minute exposure limit, our observing sequence allows one 20-minute science exposure in the acquisition orbit and two exposures (totalling 38 minutes) in each succeeding orbit as follows: acquisition orbit: GS ACQ (8m); LSA ACQ (11m); O/H (4m); G160M (1540 Angstrom) ACCUM (20m) second orbit: GS re- ACQ (6m); O/H (4m); G160M (1400 Angstrom) ACCUM (20m); O/H (4m); G160M (1400 Angstrom) ACCUM (18m). Two orbits and 3 individual exposures will be needed for each visit, hence our program requires 6 orbits and will obtain 9 exposures. The representative continuum flux over the entire spectral range to be observed is 4.e-13 erg/sec/cm**2/Angstrom; so a typical calculation shows that for this flux level at 1380 Angstrom, we will obtain 0.26 counts per diode per sec such that in 2280 sec (38 min), we expect about 590 counts or a S/N of 24 per diode. No special calibrations are needed for our observations. Real Time Justification ----------------------- Observations should be executed three times at different orbital phases, preferably within the same orbital cycle of 5.9 days; ideally, the first observation should start about 3.0 days after the mid-eclipse, defined by the ephemeris: T(mid-ecl) = HJD 243329.00 + 5.9045505 * E. The second observation should be made 1.0 days later, and the third should follow after another 1.0 days. In other words, the observations should be made at orbital phases near 0.51 P, 0.68 P, and 0.85 P. The actual timing should lie within +/- 0.2 days of the times indicated above. It is important to execute the observations within one orbital cycle, or over two adjacent orbital cycles, since the object undergoes fairly large flux variations from cycle to cycle. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6493( 7) - 04/17/96 13:32 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD65607 STAR,A0-A3 V- RA=07H 59M 16.365S +/-0.05S, J2000 V=-3 V = 8.2 IV,INTERACTING DEC=-07D 30' 18.04" +/-0.1", B-V = 0.03 BINARY,ALGOL SYSTEM PLATE-ID=03VY TYPE=A2IV E(B-V) = 0.00 A(V) = 0.0 F-CONT(1540)=4+/-1e-13 F-CONT(1400)=4+/-1e-13 F-LINE(1550)=15+/-2e-13 F-LINE(1403)=16+/-2e-13 Comments: ECLIPSING BINARY, BUT WILL BE OBSERVED OUTSIDE ECLIPSE, THUS BRIGHTNESS VARIATIONS ARE NOT LARGE TARGET COORDINATES ARE GSC VALUES. (Hipparcos coord differ by .006 sec in RA (~.09 arcsec) and .44 arcsec in DEC. We do not see any need to change the values on the basis of these modest differences.) Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1983.5 -0.0005 -0.001 0.00 6493( 7) - 04/17/96 13:32 - [ 4] Visit: 01 Visit Requirements: PERIOD 5.9045505D AND ZERO-PHASE JD2433329.00 SEQ 1-3 WITHIN 3.0D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD65607 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 100-200 Comments: STEP-TIME assumed to be .2 seconds for 3x3 search. ------------------------------------------------------------------------------------------------------------------------------------ 100 HD65607 HRS ACCUM 2.0 G160M 1550 FP-SPLIT=FOUR 1 1632S PHASE 0.50 TO 0.53 NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ 200 HD65607 HRS ACCUM 2.0 G160M 1400 FP-SPLIT=FOUR 2 1196.8S NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ 6493( 7) - 04/17/96 13:32 - [ 5] Visit: 02 Visit Requirements: PERIOD 5.9045505D AND ZERO-PHASE JD2433329.00 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD65607 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 100-200 Comments: STEP-TIME assumed to be .2 seconds for 3x3 search. ------------------------------------------------------------------------------------------------------------------------------------ 100 HD65607 HRS ACCUM 2.0 G160M 1550 FP-SPLIT=FOUR 1 1632S PHASE 0.67 TO 0.70 NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ 200 HD65607 HRS ACCUM 2.0 G160M 1400 FP-SPLIT=FOUR 2 1196.8S NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ 6493( 7) - 04/17/96 13:32 - [ 6] Visit: 03 Visit Requirements: PERIOD 5.9045505D AND ZERO-PHASE JD2433329.00 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD65607 HRS ACQ 2.0 MIRROR-N2 1 1.8S ONBOARD ACQ FOR 100-200 Comments: STEP-TIME assumed to be .2 seconds for 3x3 search. ------------------------------------------------------------------------------------------------------------------------------------ 100 HD65607 HRS ACCUM 2.0 G160M 1550 FP-SPLIT=FOUR 1 1632S PHASE 0.84 TO 0.87 NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ 200 HD65607 HRS ACCUM 2.0 G160M 1400 FP-SPLIT=FOUR 2 1196.8S NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ 6493( 7) - 04/17/96 13:32 - [ 7] Summary Form for Proposal 6493 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FP-SPLIT=FOUR ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category BINARIES AND STAR FORMATION ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PERIOD 5.9045505D AND ZERO-PHASE JD2433329.00 SEQ 1-3 WITHIN 3.0D ONBOARD ACQ FOR 100-200 PHASE 0.50 TO 0.53 NO SPLIT PERIOD 5.9045505D AND ZERO-PHASE JD2433329.00 PHASE 0.67 TO 0.70 NO SPLIT PHASE 0.84 TO 0.87 NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD65607 ------------------------------------------------------------------------------------------------------------------------------------