Characterization of the extended atmosphere and the nature of the hot super-Earth 55 Cnc e and the warm Jupiter 55 Cnc b

0 Assigned ID: 41 ----- Attempting Submission 1 (Fri Apr 03 13:28:49 GMT 2015) ----- HST Phase I Proposal 41 (apt_55Cnc.apt) successfully submitted. Receipt: # 41-1 I have rescheduled the wavelength calibrations in each orbit of visits #1 and #3 to after the scientific exposure 587150800 ----- Attempting Submission 1 (Tue Jul 07 12:42:01 GMT 2015) ----- HST Phase II Proposal 14094 (apt_55Cnc.apt) successfully submitted. Receipt: # 14094-1 ----- Attempting Submission 2 (Mon Aug 10 18:37:40 GMT 2015) ----- Characterization of the extended atmosphere and the nature of the hot super-Earth 55 Cnc e and the warm Jupiter 55 Cnc b The super-Earth 55 Cnc e transits an extremely bright star (V=6) at a very short separation (a=0.016 au). The mean density of this planet suggests it is surrounded by a thick gaseous envelope, yet our observations at Lyman-alpha detected no significant amounts of hydrogen or water. Located within a carbon-rich system, 55 Cnc e might be a 'Super-Venus' with a carbon-dioxyde envelop containing metals such as Mg. We propose to further constrain the nature of this planet through COS observations in the CII line, to assess the presence of an extended cloud rich in ionized carbon produced by the photodissociation of the irradiated CO2 envelope. We will further characterize the structure of this cloud through observations in the MgI line, recently revealed as a sensitive probe of extended atmospheres. We also detected significant Ly-alpha absorption at the inferior conjunction of the warm giant 55 Cnc b, suggesting that we witnessed the partial transit of an extended hydrogen envelope around a non-transiting planet grazing the star. The planet lies beyond 0.1 au and is thus in a lower regime of irradiation than hot Jupiters. We propose to use absorption lines to confirm the presence of an extended atmosphere around 55 Cnc b, and to investigage its regime of evaporation. We will observe simultaneously the atmospheric transits of 55 Cnc e and b in the third visit. Both STIS and COS proposed spectral ranges will allow us to look for many additional species in the upper atmospheres of these two planets, in completely different regimes of mass and irradiation. This program consists in 3 visits for a total of 13 HST orbits, dedicated to the observations of the transits of two exoplanets (55 Cancri 'e' and 'b') in front of their host-star. Following the difficulty identified by the TAC to disentangle between the signatures of 55 Cancri 'e' and 'b', we selected the same settings for the transit of 55 Cancri e (Visit #2) and the transit of both 55 Cancri 'e' and 'b' (Visit #3). In 2 visit of 4 orbits each (Visits #1 and #2) we will observe the transit of 55 Cancri 'e'. For planet 'e', transits occur every 17.7 hours (the orbital period of the planet) and last for about 1.5 hours In 1 visit of 5 orbits (Visit #3) we will observe at the same time the transits of 55 Cancri 'e' and 'b'. There are about 6 favorable configurations per year for this. Note that 55 Cnc b is not refered to as a transiting planet because its planetary disk (as seen in the optical) does not cross in front of the star. We refer here to the partial transit of its atmosphere when the planet is at inferior conjunction with the star, that is expected to last for about 4 hours and to occur every 14.65 days. For Visits #1 and #2 the timing requirements are set as phase constraints on the first ACQ exposure of the first orbit in a visit. The goal is to observe the star during two HST orbits before the transit, one HST orbit during the transit, and one HST orbit after the transit. The allowed start phase range is ~26 min. For Visit #3 the goal is to cover the transits of both planets 'e' and 'b'. We indicate in the timing requirements the specific dates when the transits of both planets can be observed at about the same time (these dates cover the next two years until June 2017). For each of these dates, the phase constraints are the same, and are set on the first ACQ exposure of the first orbit (using the period and zero phase of planet 55 Cancri 'e'). EXTRA-SOLAR PLANETS 12 false true false false AVAILABLE STAR EXTRA-SOLAR PLANETARY SYSTEM G V-IV NO This star is in a double system (common proper motions) with 55 Cancri B (GJ 324B), a much fainter (V=13) M4 dwarf that is 1.4-arcmin away. It also 4.6-arcmin away from the similarly bright (V=6.3) star 53 Cancri (BO Cancri) HR3522 GJ324A J2000 J2000 U=7.45, B=6.82, R=5.4, I=5.0, J=4.59, H=4.14, K=4.015 STIS/NUV-MAMA Spectroscopic No No E230M 2707 COS/FUV Spectroscopic No No G130M 1222 /private/var/folders/33/rs56p2wx5q174bfyvvm_nq1m0000gn/T/OPVisit1875645915173899101.xml 1439231805459 Phase windows are not calculated when the gap between schedulable intervals is less than 1 days, assuming no scheduling restrictions for constraint Phase 0.785/0.810. The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14094 :visit-id "01" :proposal-version -1 :trans-version "20150609" :date "10-Aug-2015 20:36:43.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 2229408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14094 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14094 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2657 :al-overhead-at-end 81 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2766 :al-overhead-at-end 81 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2766 :al-overhead-at-end 81 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2766 :al-overhead-at-end 81 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) true 4 0 For the ACQ and ACQ/PEAK exposures, we selected the same settings as in Program #12681 which consisted of STIS observations of the same star. We checked these settings by running the ETC. The count-rate estimated in time-tag mode results in too many buffer dumps. As an alternative for our scientific purpose, we use instead a series of ACCUM mode exposures with the optimal combination between time resolution, SNR, and buffer dumps. The count-rate estimated in time-tag mode results in too many buffer dumps. As an alternative for our scientific purpose, we use instead a series of ACCUM mode exposures with the same time resolution as the one we usually use our time-tag data. The count-rate estimated in time-tag mode results in too many buffer dumps. As an alternative for our scientific purpose, we use instead a series of ACCUM mode exposures with the same time resolution as the one we usually use our time-tag data. /private/var/folders/33/rs56p2wx5q174bfyvvm_nq1m0000gn/T/OPVisit7200689259443557155.xml 1439231813527 Phase windows are not calculated when the gap between schedulable intervals is less than 1 days, assuming no scheduling restrictions for constraint Phase 0.785/0.810. The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14094 :visit-id "02" :proposal-version -1 :trans-version "20150609" :date "10-Aug-2015 20:36:52.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 731200 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14094 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14094 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2657 :al-overhead-at-end 0 :internal-dur-at-end 67 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2768 :al-overhead-at-end 0 :internal-dur-at-end 76 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2768 :al-overhead-at-end 0 :internal-dur-at-end 76 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2768 :al-overhead-at-end 0 :internal-dur-at-end 369 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) true 4 0 We followed the recommandation of the STScI for the settings. In the ETC run, the strength of the stellar Lyman-alpha line has been set to an extremely conservative value, and the airglow as set to its higher value, in order to calculate the buffer-time. We followed the recommandation of the STScI for the settings. In the ETC run, the strength of the stellar Lyman-alpha line has been set to an extremely conservative value, and the airglow as set to its higher value, in order to calculate the buffer-time. We followed the recommandation of the STScI for the settings. In the ETC run, the strength of the stellar Lyman-alpha line has been set to an extremely conservative value, and the airglow as set to its higher value, in order to calculate the buffer-time. We followed the recommandation of the STScI for the settings. In the ETC run, the strength of the stellar Lyman-alpha line has been set to an extremely conservative value, and the airglow as set to its higher value, in order to calculate the buffer-time. /private/var/folders/33/rs56p2wx5q174bfyvvm_nq1m0000gn/T/OPVisit2989388159889374704.xml 1439231821263 Phase windows are not calculated when the gap between schedulable intervals is less than 1 days, assuming no scheduling restrictions for constraint Phase 0.785/0.810. The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. For Visit #3 the goal is to cover the transits of both planets 'e' and 'b'. We indicate in the timing requirements the specific dates when the transits of both planets can be observed at about the same time (these dates cover the next two years until June 2017). We give for each date (in UTC) a time interval of +-5h around the transit of planet 'e', which should allow to identify it with certainty. For each date the phase constraints are the same and defined using the period and zero phase of planet 55 Cancri 'e'. They are set on the first ACQ exposure of the first orbit. With these phase constraints, the 5 HST orbits in Visit #3 allow to cover the transits of both planets at all selected dates. However, experience in analyzing HST observations of atmospheric transits taught us it is better to have at least one HST orbit made before the transit, which is not the case in three of the selected dates (14 Dec. 2015; 24 April 2016; 8 June 2017). If possible (ie, unless it postpones the visit after June 2017), it would thus be better to avoid schedulind Visit #3 at one of these three dates. (Tic-Visit :proposal-id 14094 :visit-id "03" :proposal-version -1 :trans-version "20150609" :date "10-Aug-2015 20:36:59.0" :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 2804048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14094 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14094 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2657 :al-overhead-at-end 81 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2766 :al-overhead-at-end 81 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2766 :al-overhead-at-end 81 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "03" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2766 :al-overhead-at-end 81 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14094 :visit-id "03" :orbit-number 5 :pcs-time 222 :si-vis-utilization 2766 :al-overhead-at-end 81 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) true 5 0 For the ACQ and ACQ/PEAK exposures, we selected the same settings as in Program #12681 which consisted of STIS observations of the same star. We checked these settings by running the ETC. The count-rate estimated in time-tag mode results in too many buffer dumps. As an alternative for our scientific purpose, we use instead a series of ACCUM mode exposures with the same time resolution as the one we usually use our time-tag data. The count-rate estimated in time-tag mode results in too many buffer dumps. As an alternative for our scientific purpose, we use instead a series of ACCUM mode exposures with the same time resolution as the one we usually use our time-tag data. The count rate estimated from the ETC run is just above 2e4 counts/s. We thus set the buffer-time to its minimal value of 99, but the data loss should be negligible for our scientific purpose. The count-rate estimated in time-tag mode results in too many buffer dumps. As an alternative for our scientific purpose, we use instead a series of ACCUM mode exposures with the same time resolution as the one we usually use our time-tag data. The count-rate estimated in time-tag mode results in too many buffer dumps. As an alternative for our scientific purpose, we use instead a series of ACCUM mode exposures with the same time resolution as the one we usually use our time-tag data.