Supersoft sources (SSS) are a fundamental type of binary evolution that may be key to understanding Type Ia supernovae, but they remain difficult to study due to their rarity. AG Dra is the brightest SSS with an X-ray spectrum that peaks in the LETG bandpass. Our proposed observation will address the many questions that have arisen about this source based on observations in other bandpasses, including the origin of its high bolometric luminosity and whether or not the soft X-rays arise purely from the photosphere of the white dwarf. By combining LETG and HST STIS spectra, both of which could contain lines from the same ions, we will determine not only the primary emission mechanisms but also the velocities and perhaps origins of these ions. STIS observations of the symbiotic star AG Dra, 6 orbits, 2 visits: Visit 1: FUV/MAMA E140M ( total 9408s); Visit 2: NUV/MAMA E230M, 2 positions: 1978 (6048 s ) and 2707 (3330 s) Two visits separated by less than 2 days. COOL STARS 12 false false 0.0 0.0 false false false SUPPORTED STAR EMISSION LINE STAR K III-I SYMBIOTIC STAR This object was generated by the targetselector and retrieved from the SIMBAD database.' Positions and parallax fro Hipparcos Astrometric catalogue (2007) J2000 J2000 STIS/FUV-MAMA Spectroscopic No No E140M 1425 STIS/NUV-MAMA Spectroscopic No No E230M 1978 STIS/NUV-MAMA Spectroscopic No No E230M 2707 Timing link suitability includes constraints ([02 After 01 by at most 2.0 days]) The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. STIS, 1 echelle grating settings, 1 central wavlenghts, repeat 3 times (Tic-Visit :proposal-id 13107 :visit-id "01" :proposal-version -1 :trans-version "20120802" :date "13-Oct-2012 16:25:53.0" :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 278864 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13107 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13107 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3249 :al-overhead-at-end 194 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13107 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3360 :al-overhead-at-end 194 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13107 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3360 :al-overhead-at-end 194 :internal-dur-at-end 319 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) false 3 0 Timing link suitability includes constraints ([02 After 01 by at most 2.0 days]) The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13107 :visit-id "02" :proposal-version -1 :trans-version "20120802" :date "13-Oct-2012 16:27:12.0" :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 296272 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13107 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13107 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3249 :al-overhead-at-end 194 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13107 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3360 :al-overhead-at-end 194 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13107 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3360 :al-overhead-at-end 194 :internal-dur-at-end 319 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) false 3 0