6098( 9) - 11/21/95 17:18 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6098 Version: 9 Check-in Date: ********** 1.Proposal Title: Eclipse Mapping and Tomography of the UV Line Emitting Regions of DQ Herculis ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Hot Stars GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Michael Eracleous Space Telescope Science Institute CoI: Mario Livio Space Telescope Science Institute N CoI: Robert Williams Space Telescope Science Institute N CoI: Keith Horne University of Saint Andrews N CoI: Joseph Patterson Columbia University N CoI: Phillip Martell Space Telescope Science Institute N CoI: Kirk Korista University of Kentucky N ------------------------------------------------------------------------------------ 6. Abstract The old nova DQ Herculis is a cataclysmic binary which offers a rare combination of two important properties: (1) eclipses and (2) coherent periodic signals. We propose to exploit these properties in order to answer two fundamental questions: (1) to determine the origin of the UV emission lines and pulsations, and (2) to establish definitively the presence or absence of a wind, and to determine its origin. Our approach will be to use the behavior of the UV continuum and emission lines as the binary rotates, through eclipse, and over the rapid (71 s) oscillation cycle to construct eclipse maps and Doppler tomograms of the line emitting regions, and thus to locate the origin of the lines and to test for the presence of a wind. Since emission lines are an essential tool for probing the physical conditions and kinematics of cataclysmic variables, the importance of establishing their origin can hardly be overestimated. A system such as DQ Her, which is thought to lack an inner accretion disk, will also provide a crucial test for models of wind and outflow formation. ------------------------------------------------------------------------------------ 6098( 9) - 11/21/95 17:18 - [ 2] Observations Description ------------------------ We will use the FOS with the BLUE digicon detector and the G130H grating in RAPID mode, to obtain spectra with a time resolution of 5 s. The above setup will give us coverage of the region 1150 - 1606 A (see Figure 1), with a dispersion of 0.25~\AA~pix\m1\ (quarterstepping over diodes). We will employ the 1\asecb.0 aperture, with which we will achieve a spectral resolution of 0.96~\AA, corresponding to a velocity resolution of 190~\kms\ at the \CIV\ line. This resolution is adequate for our study of the line profiles and their variability over the orbital rapid oscillation cycles. To study the kinematics of the line emitting gas over the rapid oscillation cycle, the time-resolved spectra will be folded about the known pulse period, to maximize the signal-to- noise ratio (hereafter $S/N$). Real Time Justification ----------------------- In order to apply our Doppler tomographic and eclipse mapping techniques we need coverage of one complete orbital cycle, including two eclipses. The binary orbital period of our target is 4.64 hours and the duration of the eclipse is 55 minutes. Because this binary orbital period is almost an integer multiple of the 96-minute orbital period of the spacecraft, we need to visit the target twice with the FOS. In the second visit we will observe the binary phases not covered in the first visit due to earth occultation. The visibility window of the target is 55 minutes, which just barely accommodates a full eclipse (some observing time will be lost to re-acquisition of guide stars). Therefore, in order to achieve the desired coverage we need to observe for 4 spacecraft orbits on each visit. In the first visit we will begin our observation at binary orbital phase 0.56 and observe continuously for 4 spacecraft orbits. This will give us coverage of half of the orbital cycle, and two incomplete eclipses. We will return 23 hours later, after the observing window has shifted in phase by 47 minutes, to repeat the same sequence of observations and fill in the gaps left in the first visit. With this observing plan we will achieve complete coverage of the binary orbit, with a total, on-source exposure time of 330 minutes (19,800 s). Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Mike Eracleous*Will pick-up Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6098( 9) - 11/21/95 17:18 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 DQ-HER STAR, INTERACTING RA=18H 07M 30.38S +/- 0.1S, 2000 V=14.65 +/- 0.10 B-V=0.14 +/- 0.05 F- BINARY DEC=+45D 51' 31.8" +/- 0.5", CONT(1450)=1.1 +/- 0.1 E-14 F- PLATE-ID=00TB LINE(1550)=2.0 +/- 0.2 E-13 W- LINE(1550)=10 +/- 2 Comments: THE STAR IS AN ECLIPSING BINARY. THE MAGNITUDE AT MID- ECLIPSE DROPS TO V=17.1, B-V=0.2. ACQUISITION MUST OCCUR OUT OF ECLIPSE. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1983.352 0.0 0.0 0.0 6098( 9) - 11/21/95 17:18 - [ 4] Visit: 01 Visit Requirements: PERIOD 0.193620897d AND ZERO-PHASE JD2434954.9438 GROUP 1-2 WITHIN 7D 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 DQ-HER FOS/BL ACQ/BIN 4.3 MIRROR 1 10S ONBOARD ACQ FOR 2 PHASE 0.78 TO 0.80 ARY ------------------------------------------------------------------------------------------------------------------------------------ 2 DQ-HER FOS/BL RAPID 1.0 G130H READ-TIME=6.3 1 10332S ------------------------------------------------------------------------------------------------------------------------------------ 6098( 9) - 11/21/95 17:18 - [ 5] Visit: 02 Visit Requirements: PERIOD 0.193620897d AND ZERO-PHASE JD2434954.9438 GROUP 1-2 WITHIN 7D On Hold Comments: Additional Comments: THE TIMING OF THE OBSERVATIONS WITH THE RED AND BLUE DETECTORS IS VERY CRUCIAL. DO NOT CHANGE THE ORDER OF THE FOS/RD AND FOS/BL OBSERVATIONS. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DQ-HER FOS/RD ACQ/BIN 4.3 MIRROR 1 10S ONBOARD ACQ FOR 2-3 PHASE 0.57 TO 0.59 ARY ------------------------------------------------------------------------------------------------------------------------------------ 2 DQ-HER FOS/RD RAPID 1.0 G190H READ-TIME=6.3 1 9954S Comments: CHANGE DETECTORS AND GRATINGS DURING EARTH OCCULTATION. APERTURE STAYS THE SAME. ------------------------------------------------------------------------------------------------------------------------------------ 3 DQ-HER FOS/BL RAPID 1.0 G130H READ-TIME=6.3 1 11088S ------------------------------------------------------------------------------------------------------------------------------------ 6098( 9) - 11/21/95 17:18 - [ 6] Summary Form for Proposal 6098 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/BINARY RAPID ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters READ-TIME=6.3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Hot Stars ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PERIOD 0.193620897d AND ZERO-PHASE JD2434954.9438 GROUP 1-2 WITHIN 7D ONBOARD ACQ FOR 2 PHASE 0.78 TO 0.80 ONBOARD ACQ FOR 2-3 PHASE 0.57 TO 0.59 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G130H G190H ------------------------------------------------------------------------------------------------------------------------------------ Target Names DQ-HER ------------------------------------------------------------------------------------------------------------------------------------