One of the most studied extrasolar planet, HD209458b, has revealed both its lower and upper atmosphere thanks to HST and Spitzer observatories. Through transmission spectroscopy technique, several atmospheric species were detected: NaI, HI, OI and CII. Using STIS archived transit absorption spectrum from 3000 to 8000 Angstrom, we obtained detailed constraints on the vertical profile of temperature, pressure and abundances (Sing et al 2008a, 2008b, Lecavelier et al. 2008b). By observing in the NUV, from 2300 to 3100 Angstrom, we expect to obtain new constraints on the physical conditions and the chemical composition of the upper atmosphere: temperature/pressure profile up to very high in the atmosphere, abundance and condensation altitudes of new species, and new insight in the atmospheric escape and ionization state at the upper levels. The observation of four HD209458b transits with a single E230M setting will give access to many NUV atomic lines addressing these issues. The proposed observations will probe, for the first time, in details the atmosphere of a hot Jupiter, thus bench marking follow up studies.

We propose to observe during the planetary transit in front of the star HD 209458 all the stellar lines using STIS/E230M mode. The transit occurs every 3.5 days and lasts about 3 hours. Thus each visit allows to obtain scientific data for about 2 consecutive orbits during the transit. We will perform 3 visits of 5 orbits beginning before the occultation. The observations of the stellar spectrum before or after the occultation will be used as reference spectra to check the level of stellar variations. A total of 15 orbits on the 16 allocated are used to perform the present program. EXTRA-SOLAR PLANETS 12 false 0.0 0.0 false false false false false false SUPPORTED STAR G V-IV This object was generated by the targetselector and retrieved from the SIMBAD database.This object was generated by the targetselector and retrieved from the SIMBAD database. HD209458 J2000 22 03 10.8000 +18 53 4.00 J2000 STIS/NUV-MAMA Spectroscopic No No E230M 2707 Phase windows are not calculated when the period is less than 7.0 days. Assuming no scheduling restrictions for Phase 0.943/0.955. The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. Period=3.52474859 +/- 0.00000038 (days) Tc0=2452826.628521 +/- 0.000087 (HJD) From Knutson et al. 2007 1279451486000 220.87073986452094 (Tic-Visit :proposal-id 11576 :visit-id "01" :proposal-version -1 :trans-version "20090130" :date "07-Aug-2009 13:58:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 3498816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11576 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11576 :visit-id "01" :obset-id "A1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11576 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "01" :orbit-number 2 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "01" :orbit-number 3 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "01" :orbit-number 4 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "01" :orbit-number 5 :pcs-time 195 :si-vis-utilization 3028 :al-overhead-at-end 0 :internal-dur-at-end 452 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) false 5 0 Phase windows are not calculated when the period is less than 7.0 days. Assuming no scheduling restrictions for Phase 0.943/0.955. The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. Period=3.52474859 +/- 0.00000038 (days) Tc0=2452826.628521 +/- 0.000087 (HJD) From Knutson et al. 2007 (Tic-Visit :proposal-id 11576 :visit-id "02" :proposal-version -1 :trans-version "20090130" :date "07-Aug-2009 14:00:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 3498816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11576 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11576 :visit-id "02" :obset-id "A2" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11576 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "02" :orbit-number 2 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "02" :orbit-number 3 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "02" :orbit-number 4 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "02" :orbit-number 5 :pcs-time 195 :si-vis-utilization 3028 :al-overhead-at-end 0 :internal-dur-at-end 452 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) false 5 0 Phase windows are not calculated when the period is less than 7.0 days. Assuming no scheduling restrictions for Phase 0.943/0.955. The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. Period=3.52474859 +/- 0.00000038 (days) Tc0=2452826.628521 +/- 0.000087 (HJD) From Knutson et al. 2007 (Tic-Visit :proposal-id 11576 :visit-id "03" :proposal-version -1 :trans-version "20090130" :date "07-Aug-2009 15:04:20.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 3498816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11576 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11576 :visit-id "03" :obset-id "A3" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11576 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "03" :orbit-number 2 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "03" :orbit-number 3 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "03" :orbit-number 4 :pcs-time 195 :si-vis-utilization 3028 :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 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11576 :visit-id "03" :orbit-number 5 :pcs-time 195 :si-vis-utilization 3028 :al-overhead-at-end 0 :internal-dur-at-end 452 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) false 5 0 Phase windows are not calculated when the period is less than 7.0 days. Assuming no scheduling restrictions for Phase 0.200/0.300. The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. Period=3.52474859 +/- 0.00000038 (days) Tc0=2452826.628521 +/- 0.000087 (HJD) From Knutson et al. 2007 1278939324000 225.04874843264446 (Tic-Visit :proposal-id 11576 :visit-id "04" :proposal-version -1 :trans-version "20090130" :date "07-Aug-2009 15:01:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 644096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11576 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11576 :visit-id "04" :obset-id "A4" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11576 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :al-overhead-at-end 0 :internal-dur-at-end 452 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) false 1 0