12165( 2) - 09-Jul-2010 11:13:55 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12165 Version: 2 Check-in Time: 09-Jul-2010 11:13:55 STScI Edit Number: 0 Title Characterizing the UV environment of GJ1214b ------------------------------------------------------------------------------------ Type Cycle GO 18 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jean-Michel Desert Harvard University CoI: Dr. David Charbonneau Harvard University N CoI: Mr. Zachory Berta Harvard University N CoI: Mr. Philip Nutzman Harvard University N CoI: Dr. Ruth A. Murray-Clay Harvard University N CoI: Dr. Christopher J. Burke Harvard University N CoI: Dr. Jonathan Irwin Harvard University N ------------------------------------------------------------------------------------ Abstract The recent detection of a super-Earth transiting a nearby low-mass star GJ1214 (Charbonneau et al., 2009) has opened the door to testing the predictions of low mass planet atmosphere theories. Theoretical models predict that low mass planets are likely to exist with atmospheres that can vary widely in their composition and structure. Some super-Earths may be able to retain massive hydrogen-rich atmospheres. Others might never accumulate hydrogen or experience significant escape of lightweight elements, resulting in atmospheres more like those of the terrestrial planets in our Solar System. Planets which orbit close to their parent stars, such as close-in hot-Jupiters and super-Earths, are exposed to strong XEUV flux that influence their atmospheres and may trigger atmospheric escape processes. This phenomenon, which shapes planetary atmospheres, determines the evolution of the planet. This can also dramatically enhance the detectability of a heavily irradiated hydrogen atmosphere when the planet transits in front of its parent star. We propose to use HST/STIS/G140M to determine the intensity and variability of the Lyman-alpha chromospheric emission line and provide observational constraints to super-Earth atmospheric models. We propose to coordinate this measurement with a planetary transit in order to detect large upper atmospheric signatures if present. This short measurement also enables us to determine whether a larger program dedicated to upper atmospheric study is feasible for a following cycle. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe the exoplanet host-star GJ 1214 (a M dwarf) during 1 visit of 4 HST orbits. We aim at quantifying the stellar chromospheric Lyman alpha flux and the variability of this emission line. This program serves as a basis for a possible next cycle program aimed at detecting the exosphere of GJ1214. We will use the the STIS/FUV-MAMA with the G140M grating and the 52x0.05 slit. Each orbit start with an ACQ/PEAK exposure with the CCD/G750L and the 52x0.05 slit. The first exposure of the first orbit is an acquistion exposure (ACQ) with the CCD/MIRROR and the F28x50LP aperture. 12165( 2) - 09-Jul-2010 11:13:55 - [ 2] Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12165( 2) - 09-Jul-2010 11:13:55 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GJ1214 STAR, M V-IV RA=17H15M18.9400S +/- 0.1", J2000 V = 14.67 +/- 0.1 B=16.40, J=9.75, DEC=+04D57'49.70" +/- 0.1" H=9.09, K=8.78 Reference Frame: ICRS Comments: Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.53 0.039146817922343875 -0.752 0.0772 ------------------------------------------------------------------------------------------------------------------------------------ 12165( 2) - 09-Jul-2010 11:13:55 - [ 4] Visit: 01 Visit Requirements: Period 1.5804075 D AND ZERO-PHASE HJD2454983.908864 On Hold Comments: Additional Comments: This program serves as a basis for a next cycle program aimed at detecting the exosphere of GJ1214. Therefore, this single visit should be scheduled as soon as possible in order to increase the scientific outcome of this project. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GJ1214 STIS/CCD ACQ F28X50OII MIRROR ACQTYPE=POINT 1 2 S PHASE 0.899 TO 0.913 I Comments: 10sec exposure time provides a S/N=50, well below the saturation time (from ETC-ACQ simulator). The phase constraints are necessary to ensure that the planet is in transit for at least 2/3 of the 3rd orbit of the visit. ------------------------------------------------------------------------------------------------------------------------------------ 2 GJ1214 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 1 20 S K Comments: 20s exposure time provides a S/N=40 at 7751AA with the G750L and the 52x0.05 aperture, which is well below saturation (from ETC simulator). ------------------------------------------------------------------------------------------------------------------------------------ 3 GJ1214 STIS/FUV TIME-TA 52X0.05 G140M 1222 BUFFER-TIME=700 1 1521 S -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 4 GJ1214 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 1 20 S K Comments: 20s exposure time provides a S/N=40 at 7751AA with the G750L and the 52x0.05 aperture, which is well below saturation (from ETC simulator). ------------------------------------------------------------------------------------------------------------------------------------ 5 GJ1214 STIS/FUV TIME-TA 52X0.05 G140M 1222 BUFFER-TIME=700 1 1920 S -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 6 GJ1214 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 1 20 S K Comments: 20s exposure time provides a S/N=40 at 7751AA with the G750L and the 52x0.05 aperture, which is well below saturation (from ETC simulator). ------------------------------------------------------------------------------------------------------------------------------------ 7 GJ1214 STIS/FUV TIME-TA 52X0.05 G140M 1222 BUFFER-TIME=700 1 1920 S -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 12165( 2) - 09-Jul-2010 11:13:55 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 8 GJ1214 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 1 20 S K Comments: 20s exposure time provides a S/N=40 at 7751AA with the G750L and the 52x0.05 aperture, which is well below saturation (from ETC simulator). ------------------------------------------------------------------------------------------------------------------------------------ 9 GJ1214 STIS/FUV TIME-TA 52X0.05 G140M 1222 BUFFER-TIME=700 1 1920 S -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ GJ1214 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A II GJ1214 2 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 none none none none 1 N/A K GJ1214 3 STIS/FUV TIME-TA 52X0.05 G140M 1222 none none none none 1 N/A -MAMA G GJ1214 4 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 none none none none 2 N/A K GJ1214 5 STIS/FUV TIME-TA 52X0.05 G140M 1222 none none none none 2 N/A -MAMA G GJ1214 6 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 none none none none 3 N/A K GJ1214 7 STIS/FUV TIME-TA 52X0.05 G140M 1222 none none none none 3 N/A -MAMA G GJ1214 8 STIS/CCD ACQ/PEA 52X0.05 G750L 7751 none none none none 4 N/A K GJ1214 9 STIS/FUV TIME-TA 52X0.05 G140M 1222 none none none none 4 N/A -MAMA G 12165( 2) - 09-Jul-2010 11:13:55 - [ 6] Summary Form for Proposal 12165 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.05, F28X50OIII ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ, ACQ/PEAK, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT, BUFFER-TIME=700 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PHASE 0.899 TO 0.913, Period 1.5804075 D AND ZERO-PHASE HJD2454983.908864 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140M, G750L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names GJ1214 ------------------------------------------------------------------------------------------------------------------------------------