12681( 2) - 22-Jul-2011 01:12:36 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12681 Version: 2 Check-in Time: 22-Jul-2011 01:12:36 STScI Edit Number: 0 Title Search for a photodissociated evaporating ocean on the super-Earth 55 Cancri e ------------------------------------------------------------------------------------ Type Cycle GO/DD 18 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. David Ehrenreich Universite de Grenoble I CoI: Dr. Alfred Vidal-Madjar CNRS, Institut d'Astrophysique de Paris N CoI: Dr. Alain Lecavelier des Etangs CNRS, Institut d'Astrophysique de Paris N CoI: Dr. David Kent Sing University of Exeter N CoI: Dr. Guillaume Hebrard CNRS, Institut d'Astrophysique de Paris N CoI: Dr. Xavier Delfosse Universite de Grenoble I N CoI: Dr. Stephane Udry Observatoire de Geneve N ------------------------------------------------------------------------------------ Abstract The super-Earth exoplanet 55 Cancri e was recently detected in transit of its extremely bright (V=6) star. The different planet radii and densities measured in the visible with MOST and in the near-infrared with Spitzer suggest that this planet host at least 10% of water in mass, most likely in the form of a thick gaseous envelope. The planet features an extreme equilibrium temperature and a small Roche lobe, both in favor of an escape of atmospheric water which should be promptly dissociated beyond the Roche lobe. Because the star is exceptionnally close to Earth, the halo of atomic hydrogen resulting from the water dissociation is observable with HST at Lyman alpha. The detection of this atomic hydrogen will be the first signature of an evolved evaporating ocean on an extrasolar planet as well as the first validation of internal structure models of exoplanets in this mass regime. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program consists in 2 visits of 4 orbits. In each visit, we will observe the transit of an exoplanet in front of its parent star, which happens every 0.73 day and lasts for about 1.7h. Thus, each visit will completely cover the transit. The timing requirements are set as phase constraints on the first acquisition (ACQ) exposure of the first orbit of each visit. The given phase is specified so that the 2 first science exposures (1 science exposure is done during each orbit) can be completed before the transit, the third science exposure can occur during the transit, and the fourth science exposure can occur completely after the transit. Having the third (science part of the) orbit completed integrally during the transit is essential for the success of the program. The phase constraints given for the first orbit authorize a margin of 10 min. There is also an ACQ/PEAK exposure at the beginning of each visit: it is set with the G430L grating (the detector would get saturated with the mirror) and the 52"x0.05" slit, while the science exposures are to be done with the G140M grating and the 52"x0.1". Real Time Justification 12681( 2) - 22-Jul-2011 01:12:36 - [ 2] ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12681( 2) - 22-Jul-2011 01:12:36 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 55CANCRI STAR, EXTRA-SOLAR RA=08H52M35.8109S +/- 0.1", J2000 V = 26.6 V = 5.95 B=6.82, R=5.4, I=5.0, J=4.768, PLANETARY SYSTEM, G DEC=+28D19'50.95" +/- 0.1" H=4.265, K=4.015 V-IV, K V-IV Reference Frame: ICRS Comments: 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). Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.03679373930991556 -0.23405 0.08103 ------------------------------------------------------------------------------------------------------------------------------------ 12681( 2) - 22-Jul-2011 01:12:36 - [ 4] Visit: 01 Visit Requirements: Period 0.7365400 D AND ZERO-PHASE HJD2455607.05562 On Hold Comments: Additional Comments: First transit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 55CANCRI STIS/CCD ACQ F28X50OII MIRROR ACQTYPE=POINT 1 1 S PHASE 0.792 TO 0.802; SEQ 1-4 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 55CANCRI STIS/CCD ACQ/PEA 52X0.05 G430L 4300 1 1 S K ------------------------------------------------------------------------------------------------------------------------------------ 3 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000, WAVECAL=NO 1 2126 S -MAMA G see below ------------------------------------------------------------------------------------------------------------------------------------ 4 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 5 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 3005 S SEQ 5-6 NON-INT -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 6 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 7 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 3005 S SEQ 7-8 NON-INT -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 8 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 9 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 3005 S SEQ 9-10 NON-INT -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 10 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ 55CANCRI 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A I 55CANCRI 2 STIS/CCD ACQ/PEA 52X0.05 G430L 4300 none none none none 1 N/A K 55CANCRI 3 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 1 2040.0 S -MAMA G 12681( 2) - 22-Jul-2011 01:12:36 - [ 5] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WAVE 4 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 1 N/A -MAMA 55CANCRI 5 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 2 N/A -MAMA G WAVE 6 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 2 N/A -MAMA 55CANCRI 7 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 3 N/A -MAMA G WAVE 8 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 3 N/A -MAMA 55CANCRI 9 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 4 N/A -MAMA G WAVE 10 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 4 N/A -MAMA 12681( 2) - 22-Jul-2011 01:12:36 - [ 6] Visit: 02 Visit Requirements: Period 0.7365400 D AND ZERO-PHASE HJD2455607.05562 On Hold Comments: Additional Comments: Second transit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 55CANCRI STIS/CCD ACQ F28X50OII MIRROR ACQTYPE=POINT 1 1 S PHASE 0.792 TO 0.802; SEQ 1-4 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 55CANCRI STIS/CCD ACQ/PEA 52X0.05 G430L 4300 1 1 S K ------------------------------------------------------------------------------------------------------------------------------------ 3 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000, WAVECAL=NO 1 2126 S -MAMA G see below ------------------------------------------------------------------------------------------------------------------------------------ 4 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 5 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 3005 S SEQ 5-6 NON-INT -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 6 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 7 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 3005 S SEQ 7-8 NON-INT -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 8 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 9 55CANCRI STIS/FUV TIME-TA 52X0.1 G140M 1222 BUFFER-TIME=1000 1 3005 S SEQ 9-10 NON-INT -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 10 WAVE STIS/FUV ACCUM 52X0.1 G140M 1222 1 DEF -MAMA ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ 55CANCRI 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A I 55CANCRI 2 STIS/CCD ACQ/PEA 52X0.05 G430L 4300 none none none none 1 N/A K 55CANCRI 3 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 1 2040.0 S -MAMA G 12681( 2) - 22-Jul-2011 01:12:36 - [ 7] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WAVE 4 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 1 N/A -MAMA 55CANCRI 5 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 2 N/A -MAMA G WAVE 6 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 2 N/A -MAMA 55CANCRI 7 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 3 N/A -MAMA G WAVE 8 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 3 N/A -MAMA 55CANCRI 9 STIS/FUV TIME-TA 52X0.1 G140M 1222 none none none none 4 N/A -MAMA G WAVE 10 STIS/FUV ACCUM 52X0.1 G140M 1222 none none none none 4 N/A -MAMA 12681( 2) - 22-Jul-2011 01:12:36 - [ 8] Summary Form for Proposal 12681 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.05, 52X0.1, F28X50OII ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/PEAK, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT, BUFFER-TIME=1000, WAVECAL=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PHASE 0.792 TO 0.802, Period 0.7365400 D AND ZERO-PHASE HJD2455607.05562, SEQ 1-4 NON-INT, SEQ 5-6 NON-INT, SEQ 7-8 NON-INT, SEQ 9-10 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140M, G430L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names 55CANCRI, WAVE ------------------------------------------------------------------------------------------------------------------------------------