PERIOD, ZERO-PHASE, and PHASE updates to visit 03 as per PI. ----- Attempting Submission 4 (Fri Jan 18 14:38:50 GMT 2008) ----- The observation of the HD209458b transits in Lyman-alpha revealed that the atmosphere of this planet is escaping. These observations raised the question of the evaporation state of hot-Jupiters. Is the evaporation specific to HD209458b or general to hot-Jupiters? What is the evaporation mechanism, and how does the escape rate depend on the planetary system characteristics? The recent discovery of HD189733b, a planet transiting a bright and nearby K0 star (V=7.7), offers the unprecedented opportunity to answer these questions. Indeed, among the stars harboring transiting planets, HD189733 presents the largest apparent brightness in Lyman-alpha, providing capabilities to constrain the escape rate to high accuracy. With ACS/PR110L we will observe stellar emission lines to search for atmospheric absorptions during the transits. HD189733b being a very short period planet orbiting a nearby late type star with bright chromospheric emission lines, it is by far the best target to make significant progress in that field.

We will observe 3 transits of HD189733b by using 2 visits of 4 HST orbits each and 1 visit of 3 HST orbits. At each HST orbit, we propose to observe 4 times 250 seconds with PR110L at 2 dithering positions. For each HST orbit, first we take a F115LP image to calibrate the wavelength zero point. With an exposure time of 60s, this image will have a S/N ratio of about 30. The remaining time is used to observe at Lyman-alpha using PR110L with 4 separate exposures of 250 s. At each HST orbit, this sequence is repeated twice at two dithering positions. For each visit, the time constraints are given by a phase requirement calculated to allow a full HST orbit observation to be executed before and after the planetary transit as seen in Lyman-alpha. We estimated that the first exposure of the first orbit of Visits #1 and #2 must be taken at a phase in the range 0.935-0965; the first exposure of the first orbit of Visit #3 must be taken at a phase in the range 0.962-0.976. The Visit #4 is used to perfom WFPC observations of the HD189733 field to perfom the BOP check. This is done by images using F160BW filter with 15 degree partial rotation (F160BN15) for the largest field of view, and using F218W filter images. STAR FORMATION 12 false 0.0 0.0 false false false false false SUPPORTED STAR EXTRA-SOLAR PLANET K V-IV This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 20 00 43.7133 +22 42 39.07 J2000 ACS/SBC Spectroscopic No No PR110L POS-TARG DITHER 0.472 LINE false false 2 44.4 ACS-SBC-DITHER-LINE 1 false POS-TARG DITHER 0.559017 LINE 0.559017 false false 143.1301 4 26.56505 WFPC2-BOX 2 false (Tic-Visit :proposal-id 10869 :visit-id "01" :proposal-version -1 :trans-version "20061222" :date "23-Jan-2007 16:15:51.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 740544 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10869 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10869 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2790 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2771 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "01" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2771 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "01" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2768 :al-overhead-at-end 0 :internal-dur-at-end 261 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) false 4 0 (Tic-Visit :proposal-id 10869 :visit-id "02" :proposal-version -1 :trans-version "20061222" :date "23-Jan-2007 13:31:22.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 740544 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10869 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10869 :visit-id "02" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2790 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "02" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2771 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "02" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2771 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "02" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2768 :al-overhead-at-end 0 :internal-dur-at-end 261 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) false 4 0 (Tic-Visit :proposal-id 10869 :visit-id "03" :proposal-version -1 :trans-version "20061222" :date "23-Jan-2007 16:23:40.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 555408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10869 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10869 :visit-id "03" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2790 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "03" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2771 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10869 :visit-id "03" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2748 :al-overhead-at-end 0 :internal-dur-at-end 261 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) false 3 0 Visit of 1 orbit for BOP check. (Tic-Visit :proposal-id 10869 :visit-id "04" :proposal-version -1 :trans-version "20061222" :date "23-Jan-2007 11:39:55.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10869 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10869 :visit-id "04" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2760 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) true 1 0