An important HST UV legacy is the measurement of the masses of Cepheids. HST has provided double-lined spectroscopic binaries since the orbital velocity amplitude of hot companions can be measured on high resolution ultraviolet spectra. STIS UV E140H echelle observations of the Cepheid V350 Sgr will yield a dramatic improvement in the precision of its mass (5% or 0.25 solar masses vs the current 17%). This will allow a unique and critical test of the role of convective overshoot in the evolution of intermediate mass stars, by coupling the measured mass with a luminosity. Furthermore, the very accurate masses (1-2%) recently determined for two Cepheids in eclipsing binaries in the LMC mean the mass--luminosity relation for Cepheids can be compared for two metallicities. This will improve both confidence in the use of Cepheids as primary extragalactic distance indicators and also our understanding of the evolution of intermediate mass stars. There are four identical visits of three orbits each. Auto-wavecals will be turned off and replaced with deep wavecals at the beginning and end of each orbit. All but the first wavecal hide in the occultations and or guide-star re-acquisitions. Other than the initial ACQ, the exposures for each orbit are put into a non-interruptable sequence to ensure that the wavecals stay close in time to each bracketed science exposure. In each visit: 1st orbit (1) Acquire target with 3s F28X52OIII ACQ exposure (2) 3 s ACQ/PEAK with G430L and 0.2X0.09 aperture (2) 120 s WAVE (3) 1770 s E140H 1416 (4) 250 s WAVE 2nd and 3rd orbits (1) 250 s WAVE (2) 2990 s E140H 1416 (3) 250 s WAVE Notes to schedulers: The STIS FUV detector background rate increases with time after detector HV turn-on. Since our target is rather faint, please SCHEDULE EACH VISIT AS THE FIRST FUV MAMA VISIT IN THAT DAY'S SAA FREE BLOCK, and START THE VISIT AS SOON AS POSSIBLE AFTER THAT DAY'S FUV HV RAMPUP. These observations are timed to coincide with a particular phase of the binary system's four year orbital period and so should all execute between 15 Sep 2013 and 10 Nov 2013. After 10 Nov the target enters solar exclusion and cannot be observed again until mid-February, well after the requested phase window. It would be best if all visits execute within the same four day period to minimize the binary's velocity change between visits, but as the FUV MAMA dark rate increases with HV on time, no more than 1 visit should be executed during each SAA free block of orbits (this is the reason for the "AFTER BY" constraints included on visits 2, 3, and 4). If this combination of constraints should prove unschedulable, some of the requirements may be slightly relaxed after discussion with the proposal team. Bright object screening: The "unknown" objects reported by the BOT are just extra catalog entries for the target itself. At FUV wavelengths, the SED is dominated by the companion, not the Cephied. Adopted SED based on the large aperture, low dispersion IUE spectrum SWP44358 + LWR22766; other IUE spectra consistent. Expect global rate of 157 c/s background + 82 c/s source for E140H, 1416, 0.2X0.09 ETC calculation STIS.sp.507182 COOL STARS 12 false true 0.0 0.0 false false false AVAILABLE STAR B6-B9.5 V-IV CEPHEID COMPOSITE SPECTRAL TYPE F3-F9 Coordinates are from Hipparcos, adjusted for proper motion to epoch 2000. At FUV wavelengths, the SED is dominated by the ~ B9 or A0 companion, not the Cephied. Our adopted SED is based on the large aperture, low dispersion IUE spectrum SWP44358 + LWR22766. A few other IUE spectra taken at different epochs are consistent with these, ruling out any large scale FUV variability. Expect global rate of 157 c/s background + 82 c/s source for E140H, 1416, 0.2X0.09; ETC ID STIS.sp.507182. HD173297 HIP92013 J2000 J2000 FLAM(1417)=5e-14 STIS/FUV-MAMA Spectroscopic No No E140H 1416 STIS/FUV-MAMA Spectroscopic No No E140H 1416 Timing link suitability includes constraints ([Sequence (01 02 03 04) within 4.2 days] [02 After 01 by 0.5 to 1.5 days]) The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. Note to schedulers: The STIS FUV detector background rate increases with time after detector HV turn-on. Since our target is rather faint (about 3-4X average background), please schedule each visit as the first FUV MAMA visit in that day's SAA free block of orbits, and start the visits as soon as possible after the HV is turned on for the day. (Tic-Visit :proposal-id 13368 :visit-id "01" :proposal-version -1 :trans-version "20130502" :date "17-Jun-2013 10:48:41.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 314800 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13368 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13368 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2908 :al-overhead-at-end 424 :internal-dur-at-end 1785 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 1784 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 319 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 Expect 1e7 e- per dwell point from the source At FUV wavelengths, the SED is dominated by the companion, not the Cephied. Adopted SED based on the large aperture, low dispersion IUE spectrum SWP44358 + LWR22766; other IUE spectra consistent. Expect global rate of 157 c/s background + 82 c/s source for E140H, 1416, 0.2X0.09 Timing link suitability includes constraints ([Sequence (01 02 03 04) within 4.2 days] [02 After 01 by 0.5 to 1.5 days] [03 After 02 by 0.5 to 1.5 days]) The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. Note to schedulers: The STIS FUV detector background rate increases with time after detector HV turn-on. Since our target is rather faint, please schedule each visit as the first FUV MAMA visit in that day's SAA free block of orbits, and try to start the visits as soon as possible after the HV is turned on for the day. (Tic-Visit :proposal-id 13368 :visit-id "02" :proposal-version -1 :trans-version "20130502" :date "17-Jun-2013 10:49:16.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 314800 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13368 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13368 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2908 :al-overhead-at-end 424 :internal-dur-at-end 1785 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 1784 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 319 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 Expect 1e7 e- per dwell point from the source Expect global rate of 157 c/s background + 82 c/s source Timing link suitability includes constraints ([Sequence (01 02 03 04) within 4.2 days] [03 After 02 by 0.5 to 1.5 days] [04 After 03 by 0.5 to 1.5 days]) The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. Note to schedulers: The STIS FUV detector background rate increases with time after detector HV turn-on. Since our target is rather faint, please schedule each visit as the first FUV MAMA visit in that day's SAA free block of orbits, and try to start the visits as soon as possible after the HV is turned on for the day. (Tic-Visit :proposal-id 13368 :visit-id "03" :proposal-version -1 :trans-version "20130502" :date "17-Jun-2013 10:49:37.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 314800 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13368 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13368 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2908 :al-overhead-at-end 424 :internal-dur-at-end 1785 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 1784 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 319 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 Expect 1e7 e- per dwell point from the source Expect global rate of 157 c/s background + 82 c/s source Timing link suitability includes constraints ([Sequence (01 02 03 04) within 4.2 days] [04 After 03 by 0.5 to 1.5 days]) The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. Note to schedulers: The STIS FUV detector background rate increases with time after detector HV turn-on. Since our target is rather faint, please schedule each visit as the first FUV MAMA visit in that day's SAA free block of orbits, and try to start the visits as soon as possible after the HV is turned on for the day. (Tic-Visit :proposal-id 13368 :visit-id "04" :proposal-version -1 :trans-version "20130502" :date "17-Jun-2013 10:49:53.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 314800 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13368 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13368 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2908 :al-overhead-at-end 424 :internal-dur-at-end 1785 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 1784 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13368 :visit-id "04" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 424 :internal-dur-at-end 319 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 Expect 1e7 e- per dwell point from the source Expect global rate of 157 c/s background + 82 c/s source