14702( 7) - 11-Jul-2017 13:58:39 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14702 Version: 7 Check-in Time: 11-Jul-2017 13:58:39 STScI Edit Number: 5 Title The first mass and angular momentum loss measurements for a CV-like binary ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jeremy J. Drake Smithsonian Institution Astrophysical Y Observatory CoI: Prof. Boris T. Gaensicke The University of Warwick N CoI: Dr. Ofer Cohen University of Massachusetts - Lowell N CoI: Dr. Cecilia Garraffo Smithsonian Institution Astrophysical N Observatory CoI: Dr. Dai Takei Rikkyo University N ------------------------------------------------------------------------------------ Abstract The period distribution of close binaries, cataclysmic variables, novae and single-degenerate SN1a progenitor candidates is largely controlled by magnetically-driven mass and angular momentum loss (AML) from the M dwarf secondary. The mass loss rates for these spun-up stars remain essentially unknown and impossible to observe directly, with likely values in the range 1e-12 to 1e-15 Msun/yr. AML presciptions for CVs differ by orders of magnitude. One way to measure the mass loss rate is to observe the dM wind accrete onto its WD companion in a pre-CV very close to Roche Lobe overflow but lacking the obscuring complications and emission from an accretion disk. The measurement can be combined with realistic MHD models to understand the accretion fraction, the mass that escapes, and the AML. The best-studied nearby pre-CV is QS Vir (48pc, P=3.6hr). However, its wind accretion rates measured from 1999 HST UV spectra of the WD metal absorption lines and 2006 XMM-Newton CCD spectroscopy differ by a factor of a thousand, pointing to either a dominant CME stochastic component, or a "magnetic switch" found in MHD simulations and driven by cyclic activity on the M dwarf. HST COS spectra combined with XMM-Newton monitoring on timescales from weeks to years will tease out CME vs cyclic accretion variations. UV and X-ray measurements will provide the first consistency check of both accretion rate measurement methods. MHD models tailored to the system will enable the first quasi-direct measurements of the mass loss and AML from a CV-like binary. Our project requires 6 HST/COS orbits in Cycles 22-24, and 60ksec on XMM in Cycle 22 ------------------------------------------------------------------------------------ Observations Description ------------------------ The target of this proposal is QS Vir, a well-studied detached white dwarf plus M-dwarf binary with an orbital period of 3.61h. The aim of this program is to provide measurements of the wind loss rate of an M-dwarf by measuring (quasi)simultaneously the X-ray luminosity generated by the accretion of the wind onto the white dwarf, and the photospheric abundances of the metals ingested into the atmosphere of the white dwarf. We don't have a date of the XMM observations, so the HST visit is put "on hold" 14702( 7) - 11-Jul-2017 13:58:39 - [ 2] One additional complication is that QS Vir is eclipsing, and the COS target acquisition has to avoid the eclipse of the white dwarf, as there is no UV flux left to acquire on. ------------------------------------------------------------------------------------ 14702( 7) - 11-Jul-2017 13:58:39 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 QS-VIR STAR, COMPOSITE RA=13H49M51.9960S +/- 0.1", J2000 V = 14.8 +/- 0.3 SPECTRAL TYPE, DA, M DEC=-13D13'37.00" +/- 0.1" F(1300A)=4.5e-14erg/cm2/s/A V-IV Reference Frame: ICRS Extended: NO Comments: QS Vir is a detached WD + M-dwarf binary, which has been previously observed with HST/STIS in the FUV and NUV (O57E51010, O57E51020, O57EB1010, O57EB1020), and has a well-defined ultraviolet, flux, F(1300A)=4.5e-14erg/cm2/s/A Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.002855759270172812 0.019399999999999997 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 14702( 7) - 11-Jul-2017 13:58:39 - [ 4] Visit: 01 (QS Vir) Visit Requirements: Period 0.15075756940 D AND ZERO-PHASE HJD2448689.6372851; ON HOLD On Hold Comments: On hold until we know the window of the XMM observations Additional Comments: This visit should be scheduled as close as possible to the XMM observations of QS Vir. We will provide the exact data of the XMM observations as soon as we get to know from the XMM operations team. The target acquisition has to avoid the eclipse of the WD, as there is not sufficient UV flux left during the eclipse. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 QS-VIR COS/FUV ACQ/PEA PSA G130M 1291 NUM-POS=1 1 5 S (5 S) PHASE 0.2 TO 0.8 KXD ------------------------------------------------------------------------------------------------------------------------------------ 2 QS-VIR COS/FUV ACQ/PEA PSA G130M 1291 CENTER=DEF, STEP-SIZE=0.09, 1 5 S (5 S) KD NUM-POS=5 ------------------------------------------------------------------------------------------------------------------------------------ 3 QS-VIR COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=420, FP-POS=1 1 528 S (528 G S) ------------------------------------------------------------------------------------------------------------------------------------ 4 QS-VIR COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=420, FP-POS=2 1 528 S (528 G S) ------------------------------------------------------------------------------------------------------------------------------------ 5 QS-VIR COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=420, FP-POS=3 1 528 S (528 G S) ------------------------------------------------------------------------------------------------------------------------------------ 6 QS-VIR COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=420, FP-POS=4 1 527 S (527 G S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ QS-VIR 1 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A KXD QS-VIR 2 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A KD QS-VIR 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G QS-VIR 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G QS-VIR 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G QS-VIR 6 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G 14702( 7) - 11-Jul-2017 13:58:39 - [ 5] Summary Form for Proposal 14702 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAKD, ACQ/PEAKXD, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=420, CENTER=DEF, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, NUM-POS=1, NUM-POS=5, STEP-SIZE=0.09 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ON HOLD , PHASE 0.2 TO 0.8, Period 0.15075756940 D AND ZERO-PHASE HJD2448689.6372851 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M ------------------------------------------------------------------------------------------------------------------------------------ Target Names QS-VIR ------------------------------------------------------------------------------------------------------------------------------------