Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3607c Report Date: 09-May-96:18:45 Version: ********** Check-in Date: ********** 1.Proposal Title: QUASI-PERIODIC OSCILLATIONS IN AM HERCULIS BINARIES ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR ASTROPHYSICS GO Sub Category ERUPTIVE BINARIES ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr Ganesar Chanmugam LOUISIANA STATE UNIVERSITY USA 504-388-6840 DR ------------------------------------------------------------------------------------ 7. Abstract AM Her variables are close-binary systems in which a white dwarf with a magnetic field of 20--70 MG accretes matter from a companion star. Theoretical studies of magnetically channeled accretion flows in such systems predict that the shock formed near the white dwarf should oscillate with periods of order 0.1--1 s. Optical high- speed photometry has indeed shown the existence of such rapid, quasi-periodic oscillations in some AM Her binaries, but not in others. We will use HST to obtain simultaneous UV and optical high-speed photometry of several AM Her systems, in order to explore further the nature of the oscillations, and to extend the search into the UV. HSP observations of two systems (VV Pup and ST LMi, in which the accreting magnetic pole periodically passes behind the limb of the white dwarf) will allow detailed eclipse mapping of the accretion column and the shock oscillations to be carried out. This proposal was initially accepted for Cycle 1, but ultimately received Supplementary status in the reassessment. We are therefore resubmitting it for Cycle 2. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.30 par: 0 10. Num targs pri: 4 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HSP ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3607c PI: Dr Ganesar Chanmugam Proposal Title: QUASI-PERIODIC OSCILLATIONS IN AM HERCULIS BINARIES ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr Ganesar Chanmugam LOUISIANA STATE UNIVERSITY USA Dr Howard E Bond SPACE TELESCOPE SCIENCE USA INSTITUTE ------------------------------------------------------------------------------------ 2. Scientific Justification. (See original proposal for Scientific Justification) ------------------------------------------------------------------------------------ 3. Description of proposed observations. We will use the HSP in its PRISM mode to obtain photometry simultaneously in both the optical (F551W) and UV (F240W), with the aim of searching for high- frequency oscillations predicted to arise in the magnetic accretion columns of AM Her binaries. Since the predicted timescales are 0.1-1 sec, we will use integration times of 0.050 sec in the visual and UV for all of the observations. Two systems (EF Eri and VV Pup) have already shown oscillations in the optical, and will be observed with HST in order to characterize the oscillations in the UV. The remaining two targets (AM Her and ST LMi) do not show optical oscillations, and we will test the prediction that they will be found in the UV. We plan to obtain five photometric runs of 30 min each in length. In two of the targets, VV Pup and ST LMi, the accretion column is periodically eclipsed when it passes behind the white dwarf, and the 30-min runs will be timed to cover an ingress and egress in VV Pup, and an ingress in ST LMi. The 30-min runs on AM Her and EF Eri can be at any time. All runs must be continuous (NON-INT). ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Theoretical studies predict that shock oscillations with periods of 0.1-1 sec at X-ray, UV, and optical wavelengths will occur in the accretion columns in AM Her binaries. The observed optical oscillations are not coherent, making recovery of the signal from optical data, inevitably contaminated with atmospheric scintillation, difficult. High-speed UV photometry cannot be done at all from the ground or with IUE, making HST a unique choice for these observations. The capability of obtaining the UV and optical high-speed photometry SIMULTANEOUSLY exists only with HST. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. We wish to observe critical binary phases for two of the targets, VV Pup and ST LMi, in which the accretion columns undergo eclipses. We are requesting timing such that the three 30-min runs are centered on an ingress and egress of VV Pup, and an ingress of ST LMi. The other two targets can be observed at any time, since their accretion columns are always visible. Note that very accurate timing (+/- a few minutes) is required for the start times of the 30-min runs on VV Pup and ST LMi. Our time specifications are in HELIOCENTRIC Julian Dates. Note also that the ACQUISITION observations of VV Pup and ST LMi are time-critical. This is because these two objects are bright for only a fraction of their orbital periods, and faint for the rest of the orbital period. The acquisitions should be done during the FAINT phases, which have a longer duration and a more constant brightness level than the bright phases. It is especially important to avoid the transitions from faint to bright due to the rapidly changing light level which would ruin the acquisition. Note: do not schedule before successful calibration of HSP/PRISM mode. Page 3 ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. No special calibrations are needed. We do include a S/C mode parallel observation to assure that the guiding history is recorded at high data rate, for subsequent attempts at removing guiding jitter from the data. All five runs must be uninterrupted, and should avoid terminator crossings to the extent possible. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. (see original proposal) ------------------------------------------------------------------------------------ 8. Additional comments or special requests. (see original proposal) ------------------------------------------------------------------------------------ 9. Description of previous HST work. (See original proposal) ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). (See original proposal) ------------------------------------------------------------------------------------ 11. Address Information Name: GANESAR CHANMUGAM Category: PI Institution: LOUISIANA STATE UNIVERSITY Address: City: State: Zip Code: Country: Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3607c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 AM-HER A,153,161 PLATE-ID=00TB, J2000 1 V=12 GSC3533-1105 RA = 18H 16M 13.34S +/- 0.7", DEC = +49D 52' 04.1" +/- 0.7" Comments: FOR EACH TARGET, V MAGNITUDE GIVEN IS MAX. STARS VARY ON TIMESCALES OF MINUTES TO MONTHS BY UP TO SEVERAL MAGNITUDES. ------------------------------------------------------------------------------------------------------------------------------------ 2 EF-ERI A,153,161 PLATE-ID=027U, J2000 1 V=13.7 2A0311-227 RA = 03H 14M 13.03S +/- GSC6439-120 0.7", DEC = -22D 35' 41.3" +/- 0.7" Comments: FOR EACH TARGET, V MAGNITUDE GIVEN IS MAX. STARS VARY ON TIMESCALES OF MINUTES TO MONTHS BY UP TO SEVERAL MAGNITUDES. ------------------------------------------------------------------------------------------------------------------------------------ 3 ST-LMI A,153,161 PLATE-ID=0256, J2000 1 V=15 CW1103+253 RA = 11H 05M 39.75S +/- 0.7", DEC = +25D 06' 28.9" +/- 0.7" Comments: FOR EACH TARGET, V MAGNITUDE GIVEN IS MAX. STARS VARY ON TIMESCALES OF MINUTES TO MONTHS BY UP TO SEVERAL MAGNITUDES. ------------------------------------------------------------------------------------------------------------------------------------ 4 VV-PUP A,153,161 PLATE-ID=01Z4, J2000 1 V=14.5 RA = 08H 15M 06.73S +/- 0.7", DEC = -19D 03' 16.9" +/- 0.7" Comments: FOR EACH TARGET, V MAGNITUDE GIVEN IS MAX. STARS VARY ON TIMESCALES OF MINUTES TO MONTHS BY UP TO SEVERAL MAGNITUDES. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3607c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 AM-HER HSP/ ACQ DATA- 1 45S 1 1 ONBOARD ACQ FOR 2 VIS FORMAT=WORD PCS MODE F CYCLE 2 ------------------------------------------------------------------------------------------------------------------------------------ 2 AM-HER HSP/ PRISM 1.0 F551W/ SAMPLE- 1 27.37M 1 1 PCS MODE F VIS F240W TIME=0.050 NON-INT PRECISION=HIGH CYCLE 2 Comments: OBSERVATION IS VERY SENSITIVE TO JITTER; SHOULD BE SCHEDULED TO AVOID DAY-NIGHT TRANSITIONS IF POSSIBLE; OR TRANSITIONS SHOULD BE AT BEGINNING OR END OF EXPOSURE. ------------------------------------------------------------------------------------------------------------------------------------ 2.5 DARK S/C DATA NONE FORMAT=FN 1 1S 1 PAR WITH 2 CRIT OBS CYCLE 2 Comments: THE FN FORMAT IS SPECIFIED IN ORDER TO ASSURE THAT THE ENGINEERING DATA ARE RECORDED AT 32 KBPS, FOR SUBSEQUENT ATTEMPTS TO REMOVE GUIDING JITTER FROM THE HSP PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 3 EF-ERI HSP/ ACQ DATA- 1 45S 1 1 ONBOARD ACQ FOR 4 VIS FORMAT=WORD PCS MODE F CYCLE 2 ------------------------------------------------------------------------------------------------------------------------------------ 4 EF-ERI HSP/ PRISM 1.0 F551W/ SAMPLE- 1 27.37M 1 1 PCS MODE F VIS F240W TIME=0.050 NON-INT PRECISION=HIGH CYCLE 2 Comments: OBSERVATION IS VERY SENSITIVE TO JITTER; SHOULD BE SCHEDULED TO AVOID DAY-NIGHT TRANSITIONS IF POSSIBLE; OR TRANSITIONS SHOULD BE AT BEGINNING OR END OF EXPOSURE. ------------------------------------------------------------------------------------------------------------------------------------ 4.5 DARK S/C DATA NONE FORMAT=FN 1 1S 1 PAR WITH 4 CRIT OBS CYCLE 2 Comments: THE FN FORMAT IS SPECIFIED IN ORDER TO ASSURE THAT THE ENGINEERING DATA ARE RECORDED AT 32 KBPS, FOR SUBSEQUENT ATTEMPTS TO REMOVE GUIDING JITTER FROM THE HSP PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3607c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 ST-LMI HSP/ ACQ DATA- 1 90S 1 1 ONBOARD ACQ FOR 6 VIS FORMAT=WORD PCS MODE F CYCLE 2 PHASE 0.375 +/- 0.275 ZERO-PHASE Comments: THE ACQUISITION IS DONE DURING JD2445059.7024 +/- THE FAINT PHASE OF ST LMI. NOTE 0.0003D THAT THE ZERO-PHASE IS GIVEN AS PERIOD 0.07908908D A HELIOCENTRIC JULIAN DATE FOR +/- 0.0000008D ALL OBSERVATIONS. ------------------------------------------------------------------------------------------------------------------------------------ 6 ST-LMI HSP/ PRISM 1.0 F551W/ SAMPLE- 1 30M 1 1 PCS MODE F VIS F240W TIME=0.050 NON-INT PRECISION=HIGH CYCLE 2 PHASE 0.868 +/- 0.050 ZERO-PHASE Comments: OBSERVATION IS VERY SENSITIVE JD2445059.7024 +/- TO JITTER; SHOULD BE SCHEDULED 0.0003D TO AVOID DAY-NIGHT TRANSITIONS PERIOD 0.07908908D IF POSSIBLE; OR TRANSITIONS +/- 0.00000008D SHOULD BE AT BEGINNING OR END OF EXPOSURE. THIS IS INGRESS OBSERVATION OF ST LMI. ------------------------------------------------------------------------------------------------------------------------------------ 6.5 DARK S/C DATA NONE FORMAT=FN 1 1S 1 PAR WITH 6 CRIT OBS CYCLE 2 Comments: THE FN FORMAT IS SPECIFIED IN ORDER TO ASSURE THAT THE ENGINEERING DATA ARE RECORDED AT 32 KBPS, FOR SUBSEQUENT ATTEMPTS TO REMOVE GUIDING JITTER FROM THE HSP PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 7 VV-PUP HSP/ ACQ DATA- 1 60S 1 1 ONBOARD ACQ FOR 8, VIS FORMAT=WORD 9 PCS MODE F CYCLE 2 PHASE 0.45 +/- 0.25 Comments: THE ACQUISITION IS DONE DURING ZERO-PHASE THE FAINT PHASE OF VV PUP. NOTE JD2427889.6474 +/- THAT THE ZERO-PHASE IS GIVEN AS 0.0001D A HELIOCENTRIC JULIAN DATE FOR PERIOD ALL OBSERVATIONS. 0.0697468256D +/- 0.0000000003D ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3607c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 8 VV-PUP HSP/ PRISM 1.0 F551W/ SAMPLE- 1 30M 1 1 PCS MODE F VIS F240W TIME=0.050 NON-INT PRECISION=HIGH CYCLE 2 PHASE 0.981 +/- 0.050 ZERO-PHASE Comments: OBSERVATION IS VERY SENSITIVE JD2427889.6474 +/- TO JITTER; SHOULD BE SCHEDULED 0.0001D TO AVOID DAY-NIGHT TRANSITIONS PERIOD IF POSSIBLE; OR TRANSITIONS 0.0697468256D +/- SHOULD BE AT BEGINNING OR END 0.0000000003D OF EXPOSURE. THIS IS INGRESS OBSERVATION OF VV PUP. ------------------------------------------------------------------------------------------------------------------------------------ 8.5 DARK S/C DATA NONE FORMAT=FN 1 1S 1 PAR WITH 8 CRIT OBS CYCLE 2 Comments: THE FN FORMAT IS SPECIFIED IN ORDER TO ASSURE THAT THE ENGINEERING DATA ARE RECORDED AT 32 KBPS, FOR SUBSEQUENT ATTEMPTS TO REMOVE GUIDING JITTER FROM THE HSP PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 9 VV-PUP HSP/ PRISM 1.0 F551W/ SAMPLE- 1 30M 1 1 PCS MODE F VIS F240W TIME=0.050 NON-INT PRECISION=HIGH CYCLE 2 PHASE 0.621 +/- 0.050 ZERO-PHASE Comments: OBSERVATION IS VERY SENSITIVE JD2427889.6474 +/- TO JITTER; SHOULD BE SCHEDULED 0.0001D TO AVOID DAY-NIGHT TRANSITIONS PERIOD IF POSSIBLE; OR TRANSITIONS 0.0697468256D +/- SHOULD BE AT BEGINNING OR END 0.0000000003D OF EXPOSURE. THIS IS EGRESS OBSERVATION OF VV PUP. ------------------------------------------------------------------------------------------------------------------------------------ 9.5 DARK S/C DATA NONE FORMAT=FN 1 1S 1 PAR WITH 9 CRIT OBS CYCLE 2 Comments: THE FN FORMAT IS SPECIFIED IN ORDER TO ASSURE THAT THE ENGINEERING DATA ARE RECORDED AT 32 KBPS, FOR SUBSEQUENT ATTEMPTS TO REMOVE GUIDING JITTER FROM THE HSP PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3607c [ 8] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HSP/VIS S/C ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ PRISM DATA ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DATA-FORMAT=WORD SAMPLE-TIME=0.050 PRECISION=HIGH FORMAT=FN ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.30 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ERUPTIVE BINARIES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2; PCS MODE F; CYCLE 2 NON-INT; PAR WITH 2; CRIT OBS; ONBOARD ACQ FOR 4; PAR WITH 4; ONBOARD ACQ FOR 6; CYCLE 2; PHASE 0.375 +/- 0.275; ZERO-PHASE JD2445059.7024 +/- 0.0003D; PERIOD 0.07908908D +/- 0.0000008D PHASE 0.868 +/- 0.050; PERIOD 0.07908908D +/- 0.00000008D PAR WITH 6; ONBOARD ACQ FOR 8,9; PHASE 0.45 +/- 0.25; ZERO-PHASE JD2427889.6474 +/- 0.0001D; PERIOD 0.0697468256D +/- 0.0000000003D PHASE 0.981 +/- 0.050; PAR WITH 8; PHASE 0.621 +/- 0.050; PAR WITH 9; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F551W/F240W ------------------------------------------------------------------------------------------------------------------------------------ Target Names AM-HER GSC3533-1105 EF-ERI 2A0311-227 GSC6439-120 ST-LMI CW1103+253 VV-PUP ------------------------------------------------------------------------------------------------------------------------------------