Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2660c Report Date: 09-May-96:17:16 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. Howard E. Bond STSCI USA 301-338-4718 ASTRONOMER ------------------------------------------------------------------------------------ 7. Abstract AM Herculis variables are close-binary systems in which a white dwarf with a magnetic field of 20-40 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 ~0.1-1sec. Optical high-speed photometry has indeed shown the existence of such rapid 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 systes, in order to explore further the nature of the oscillations, and to extend the search into the UV. HSP observations of two syustems (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. ------------------------------------------------------------------------------------ 8. Scientific Key Words: STARS: WHITE DWARFS, CATACLYSMIC VARIABLES, MAGNETIC FIELDS, RAPID OSCILLATIONS; HIGH-SPEED PHOTOMETRY; ACCRETION ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 6.00 par: 0 10. Num targs pri: 8 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HSP ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2660c PI: Dr. Howard E. Bond Proposal Title: QUASI-PERIODIC OSCILLATIONS IN AM HERCULIS BINARIES ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr. G. Chanmugam LOUISIANA STATE UNIVERSITY USA P.I. Howard E. Bond STSCI USA ------------------------------------------------------------------------------------ 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 (visual) and 0.025 sec (UV) for all of the observations. Four systems (AN UMa, EF Eri, V834 Cen, 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 four targets (AM Her, QQ Vul, ST LMi, and MR Ser) do not show optical oscillations, and we will test the prediction that they will be found in the UV. We hope to obtain photometric runs of as long as 30 minutes. However, since the program was awarded Supplemental priority, we emphasize that RUNS AS SHORT AS A FEW MINUTES WOULD BE OF GREAT SCIENTIFIC VALUE, and are acceptable if they can be fitted into the observing schedule. In two of the targets, VV Pup and ST LMi, the accretion column is periodically eclipsed when it passes behind the white dwarf. It would be especially valuable to follow these objects with high-speed photometry as they eclipse, and we have used the appropriate Special Requirements to request such timing. Again, however, observations scheduled at any time are better than none. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. (See original proposal) ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. (See original proposal) ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. As mentioned in item 3, we wish to observe critical orbital phases for two of the targets, VV Pup and ST LMi, which are self-eclipsing systems. We have requested timing such that a 30-min run would be centered on the eclipse. The other targets can be observed at any time, since their accretion columns are always visible. High-speed photometry runs as short as a few minutes would yield important science, so it is permissible to cut the 30 minutes requested on the Exposure Logsheet if that would make it possible to schedule the observation(s). ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. (See original proposal) ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Note that one of our targets, ST LMi, is also being observed with the FOS by a Cycle-1 GO (program 2686). Moreover, AM Her, EF Eri, ST LMi, and VV Pup are being observed in the GTO programs 1051 (FOS) and/or 1155 (GHRS). Thus there will be several convenient opportunities to schedule our own Supplemental observations in sequence with other, High-priority observations of the same targets. Page 3 ------------------------------------------------------------------------------------ 9. Description of previous HST work. N/A ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). (See original proposal) ------------------------------------------------------------------------------------ 11. Address Information Name: HOWARD E. BOND Category: PI Institution: SPACE TELESCOPE SCIENCE INSTITUTE Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2660c [ 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 STAR; WHITE DWARF; PLATE-ID=00TB, J2000 1 V=12 GSC3533-1105 VARIABLE; INTERACTING RA=18H 16M 13.34S +/- 0.7", BINARY; DEC=+49D 52' 04.1" +/- 0.7" DWARF NOVA; PHOTOMETRY Comments: FOR EACH TARGET, V MAGNITUDE GIVEN IS MAX. STARS VARY ON TIMESCALES OF MINUTES TO MONTHS BY UP TO SEVERAL MAGNITUDES. ------------------------------------------------------------------------------------------------------------------------------------ 2 AN-UMA STAR; WHITE DWARF; PLATE-ID=01R5, J2000 1 V=14.5 VARIABLE; INTERACTING RA=11H 04M 25.70S +/- 0.7", BINARY; DEC=+45D 03' 15.0" +/- 0.7" DWARF NOVA; PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 3 EF-ERI STAR; WHITE DWARF; PLATE-ID=027U, J2000 1 V=13.7 2A0311-227 VARIABLE; INTERACTING RA=03H 14M 13.03S +/- 0.7", GSC6439-120 BINARY; DEC=-22D 35' 41.3" +/- 0.7" DWARF NOVA; PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 4 MR-SER STAR; WHITE DWARF; PLATE-ID=00GM, J2000 1 V=14.9 VARIABLE; INTERACTING RA=15H 52M 47.23S +/- 0.7", BINARY; DEC=+18D 56' 27.6" +/- 0.7" DWARF NOVA; PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 5 QQ-VUL STAR; WHITE DWARF; PLATE-ID=00FF, J2000 1 V=14.5 E2003+225 VARIABLE; INTERACTING RA=20H 05M 41.94S +/- 0.7", BINARY; DEC=+22D 39' 59.1" +/- 0.7" DWARF NOVA; PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 6 ST-LMI STAR; WHITE DWARF; PLATE-ID=0256, J2000 1 V=15 CW1103+253 VARIABLE; INTERACTING RA=11H 05M 39.75S +/- 0.7", BINARY; DEC=+25D 06' 28.9" +/- 0.7" DWARF NOVA; PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 7 VV-PUP STAR; WHITE DWARF; PLATE-ID=01Z4, J2000 1 V=14.5 VARIABLE; INTERACTING RA=08H 15M 06.73S +/- 0.7", BINARY; DEC=-19D 03' 16.9" +/- 0.7" DWARF NOVA; PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ 8 V834-CEN STAR; WHITE DWARF; PLATE-ID=02MC, J2000 1 V=14.2 E1405-451 VARIABLE; INTERACTING RA=14H 09M 07.48S +/- 0.7", BINARY; DEC=-45D 17' 17.0" +/- 0.7" DWARF NOVA; PHOTOMETRY ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2660c [ 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 DEFINE # HSP/ ACQ DATA- 1 40S 1 # ACQ VIS FORMAT=WORD ------------------------------------------------------------------------------------------------------------------------------------ 1.5 DEFINE # HSP/ ACQ DATA- 1 10S 1 # BRIGHTA VIS FORMAT=WORD CQ ------------------------------------------------------------------------------------------------------------------------------------ 2 DEFINE # HSP/ PRISM 1.0 F551W/ SAMPLE- 1 29.025M 1 # RUN VIS F240W TIME=0.050 2ND- SAMPLE=0.025 Comments: ALTHOUGH 30-MIN RUNS HAVE BEEN REQUESTED FOR EACH TARGET, RUNS AS SHORT AS A FEW MINUTES ARE STILL SCIENTIFICALLY USEFUL. NOTE THAT THE 0.050-SEC SAMPLE IS FOR F551W, AND THE 0.025-SEC SAMPLE IS FOR F240W. ------------------------------------------------------------------------------------------------------------------------------------ 3 USE ACQ VV-PUP 1 ONBOARD ACQ FOR 4 ------------------------------------------------------------------------------------------------------------------------------------ 4 USE RUN ^ ^ PHASE 0.851 +/- 0.050 ZERO-PHASE JD2427889.6558 +/- 0.0001D PERIOD 0.0697468256D +/- 0.0000000003D ------------------------------------------------------------------------------------------------------------------------------------ 5 USE ACQ V834-CEN 2 ONBOARD ACQ FOR 6 ------------------------------------------------------------------------------------------------------------------------------------ 6 USE RUN ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 7 USE ACQ EF-ERI 3 ONBOARD ACQ FOR 8 ------------------------------------------------------------------------------------------------------------------------------------ 8 USE RUN ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 9 USE ACQ AN-UMA 3 ONBOARD ACQ FOR 10 ------------------------------------------------------------------------------------------------------------------------------------ 10 USE RUN ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 11 USE AM-HER 4 ONBOARD ACQ FOR 12 BRIGHTA CQ ------------------------------------------------------------------------------------------------------------------------------------ 12 USE RUN ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 13 USE ACQ ST-LMI 5 ONBOARD ACQ FOR 14 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2660c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 14 USE RUN ^ ^ PHASE 0.868 +/- 0.044 ZERO-PHASE JD2445059.7024 +/- 0.0003D PERIOD 0.07908908D +/- 0.00000008D ------------------------------------------------------------------------------------------------------------------------------------ 15 USE ACQ QQ-VUL 6 ONBOARD ACQ FOR 16 ------------------------------------------------------------------------------------------------------------------------------------ 16 USE RUN ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 17 USE ACQ MR-SER 6 ONBOARD ACQ FOR 18 ------------------------------------------------------------------------------------------------------------------------------------ 18 USE RUN ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2660c [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HSP/VIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ PRISM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DATA-FORMAT=WORD SAMPLE-TIME=0.050 2ND-SAMPLE=0.025 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 6.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ERUPTIVE BINARIES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 4 PHASE 0.851 +/- 0.050; ZERO-PHASE JD2427889.6558 +/- 0.0001D; PERIOD 0.0697468256D +/- 0.0000000003D ONBOARD ACQ FOR 6 ONBOARD ACQ FOR 8 ONBOARD ACQ FOR 10 ONBOARD ACQ FOR 12 ONBOARD ACQ FOR 14 PHASE 0.868 +/- 0.044; ZERO-PHASE JD2445059.7024 +/- 0.0003D; PERIOD 0.07908908D +/- 0.00000008D ONBOARD ACQ FOR 16 ONBOARD ACQ FOR 18 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F551W/F240W ------------------------------------------------------------------------------------------------------------------------------------ Target Names AM-HER GSC3533-1105 AN-UMA EF-ERI 2A0311-227 GSC6439-120 MR-SER QQ-VUL E2003+225 ST-LMI CW1103+253 VV-PUP V834-CEN E1405-451 ------------------------------------------------------------------------------------------------------------------------------------