13859( 4) - 06-Jan-2015 15:33:30 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13859 Version: 4 Check-in Time: 06-Jan-2015 15:33:30 STScI Edit Number: 0 Title Unveiling the circumstellar environment of the most extreme hot-Jupiters ------------------------------------------------------------------------------------ Type Cycle GO 22 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Luca Fossati Universitat Bonn, Argelander Institute for Y Astronomy CoI: Dr. Tommi Koskinen University of Arizona N CoI: Dr. Kevin France University of Colorado at Boulder N CoI: Dr. Carole A. Haswell Open University N ------------------------------------------------------------------------------------ Abstract Ultraviolet HST observations have shown that atmospheric evaporation is a common feature of hot-Jupiters: highly irradiated (short-period) Jupiter-like planets. Models show that hot-Jupiters lose only a small fraction of their mass to evaporation but this may not be the case for extreme hot-Jupiters such as WASP-12b, which orbit very close to their host stars. Our Cycle 17 observations of WASP-12b showed that the planet atmosphere is evaporating and that gas escaping from the heavily irradiated planet may form a stable and thick circumstellar disk, causing an anomalously low stellar activity index. This anomaly does not allow us to correctly estimate the stellar UV flux, which drives the evaporation, from the available observational material. We request 6 HST orbits to obtain far-UV spectra of WASP-18 and WASP-13. Both stars host extreme hot-Jupiters, show an anomalously low activity index, and are much brighter than WASP-12, allowing one to obtain the necessary high quality far-UV spectra; WASP-12 is too faint at far-UV wavelengths to be measured by the instruments on-board HST. The data will allow us to improve the mass loss rates estimated for the most extreme hot-Jupiters as well as to resolve the ambiguity about the activity of the host stars in these systems. These data are necessary to correctly interpret the Cycle 17 HST observations, as well as observations of WASP-12b which have recently been obtained in Cycle-21. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe WASP-18 for 2 consecutive HST orbits and WASP-13 for 4 consecutive HST orbits to obtain FUV spectra of WASP-18 and WASP-13, respectively. The WASP-13 observations are timed with the planet transit: the hot-Jupiter WASP-13b passing in front of its parent star. The transit happens every 4.353 days and lasts about 4.08 hours. The WASP-13 observations aim at almost completely covering the planet transit. For the WASP-13 observations the timing requirements are set as phase constraints on the first acquisition (ACQ) exposure. The given phase is specified so that the first science exposure (1 science exposure is done during each orbit) falls integrally just before the ingress, the second and third science exposures occur during the transit, while the last science exposure 13859( 4) - 06-Jan-2015 15:33:30 - [ 2] occurs integrally just after the planet transit. Having the last exposure integrally after the transit is critical for the success of the program. The phase constraints given for the first orbit authorize a margin of about 4 minutes. Due to the fact that we aim at measuring the planet transit, we have set FP-POS=3, rather than equal to ALL. We submitted a Program Change Request for this (timed observations and use of one single FP-POS) which has been accepted (PCR 78372). No ACQ/PEAK is set because the coordinates of both targets are extremely precise. We will take two FUV spectra of WASP-18 and four FUV spectra of WASP-13 with the COS/FUV TIME-TAG mode using the G140L grating and the 1105 setting. WASP-18 is a late F-type main sequence star hosting a massive hot-Jupiter, while WASP-13 is an early G-type main sequence star hosting an extremely bloated and hot Saturn-mass planet. The spectrum will cover the 1118-2251 A spectral region with a spectral resolution R~2000. To calculate the exposure times of the science exposures we considered the CII lines at lambda~1335 A. We then considered the flux density of this multiplet as observed on the spectrum of alpha Cen and rescaled it to the distance of WASP-18 (100 pc) and WASP-13 (156 pc). ------------------------------------------------------------------------------------ 13859( 4) - 06-Jan-2015 15:33:30 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 WASP-18 STAR, CIRCUMSTELLAR RA=01H37M25.0341S +/- 0.00883", J2000 V = 9.3 CII emission line at 1334 A: MATTER, EXTRA-SOLAR DEC=-45D40'40.39" +/- 0.00883" estimated peak flux of 10^-15 erg A^-1 PLANET, F3-F9 s^-1; GALEX FUV flux: 2.16x10^-15 erg A^-1 s^-1; GALEX NUV flux: saturated Reference Frame: ICRS Comments: This object was generated by the target selector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0025304445458566548 0.018789999999999998 0.01006 ------------------------------------------------------------------------------------------------------------------------------------ 2 WASP-13 STAR, CIRCUMSTELLAR RA=09H20M24.7020S +/- 0.03", J2000 V = 10.42 +/- 0.06 CII emission line at MATTER, EXTRA-SOLAR DEC=+33D52'56.69" +/- 0.03" 1334 A: estimated peak flux of PLANET, F3-F9 4.3*10^-16 erg A^-1 s^-1; GALEX FUV flux: 1.9x10^-16 erg A^-1 s^-1; GALEX NUV flux: 5.0x10^-14 erg A^-1 s^-1 Reference Frame: ICRS Comments: This object was generated by the target selector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -6.665193596307452E-4 -0.022 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 13859( 4) - 06-Jan-2015 15:33:30 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Two-orbit exposure on WASP-18 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WASP-18 COS/NUV ACQ/IMA BOA MIRRORA 1 34.7 S SEQ 1-2 NON-INT GE (34.7 S) Comments: Using the PSA aperture I got a total count rate which largely exceeds the bright limit: ETC Run # COS.ta.620288 ------------------------------------------------------------------------------------------------------------------------------------ 2 WASP-18 COS/FUV TIME-TA PSA G140L 1105 FLASH=YES, SEGMENT=A, 1 600 S G EXTENDED=NO, FP-POS=ALL, see below BUFFER-TIME=6830.0 (2304 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WASP-18 COS/FUV TIME-TA PSA G140L 1105 EXTENDED=NO, FLASH=YES, 1 600 S G FP-POS=ALL, SEGMENT=A, see below BUFFER-TIME=6830.0 (2756 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WASP-18 1 COS/NUV ACQ/IMA BOA MIRRORA none none none none 1 N/A GE WASP-18 2 COS/FUV TIME-TA PSA G140L 1105 none none none 1 1 576.0 S G WASP-18 2 COS/FUV TIME-TA PSA G140L 1105 none none none 2 1 576.0 S G WASP-18 2 COS/FUV TIME-TA PSA G140L 1105 none none none 3 1 576.0 S G WASP-18 2 COS/FUV TIME-TA PSA G140L 1105 none none none 4 1 576.0 S G WASP-18 3 COS/FUV TIME-TA PSA G140L 1105 none none none 1 2 689.0 S G WASP-18 3 COS/FUV TIME-TA PSA G140L 1105 none none none 2 2 689.0 S G WASP-18 3 COS/FUV TIME-TA PSA G140L 1105 none none none 3 2 689.0 S G WASP-18 3 COS/FUV TIME-TA PSA G140L 1105 none none none 4 2 689.0 S G 13859( 4) - 06-Jan-2015 15:33:30 - [ 5] Visit: 02 Visit Requirements: Period 4.353011 D AND ZERO-PHASE HJD2455575.5136 On Hold Comments: Additional Comments: Four-orbit exposure of WASP-13 timed with the planet transit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WASP-13 COS/NUV ACQ/IMA PSA MIRRORB 1 21.8 S PHASE 0.97014 TO GE (21.8 S) 0.97473; SEQ 1-2 NON-INT Comments: The exposure time is based on the GALEX magnitude of NUV_mag=15.57 ------------------------------------------------------------------------------------------------------------------------------------ 2 WASP-13 COS/FUV TIME-TA PSA G140L 1105 FLASH=YES, EXTENDED=NO, 1 2000 S G SEGMENT=A, FP-POS=3, see below BUFFER-TIME=7277.0 (2522 S) Comments: HST Orbit 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 WASP-13 COS/FUV TIME-TA PSA G140L 1105 FLASH=YES, EXTENDED=NO, 1 2500 S G SEGMENT=A, FP-POS=3, see below BUFFER-TIME=7277.0 (2971 S) Comments: HST Orbit 2 ------------------------------------------------------------------------------------------------------------------------------------ 4 WASP-13 COS/FUV TIME-TA PSA G140L 1105 FLASH=YES, EXTENDED=NO, 1 2500 S G SEGMENT=A, FP-POS=3, see below BUFFER-TIME=7277.0 (2971 S) Comments: HST Orbit 3 ------------------------------------------------------------------------------------------------------------------------------------ 5 WASP-13 COS/FUV TIME-TA PSA G140L 1105 FLASH=YES, EXTENDED=NO, 1 2500 S G SEGMENT=A, FP-POS=3, see below BUFFER-TIME=7277.0 (2971 S) Comments: HST Orbit 4 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WASP-13 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE WASP-13 2 COS/FUV TIME-TA PSA G140L 1105 none none none none 1 2522.0 S G WASP-13 3 COS/FUV TIME-TA PSA G140L 1105 none none none none 2 2971.0 S G WASP-13 4 COS/FUV TIME-TA PSA G140L 1105 none none none none 3 2971.0 S G WASP-13 5 COS/FUV TIME-TA PSA G140L 1105 none none none none 4 2971.0 S G 13859( 4) - 06-Jan-2015 15:33:30 - [ 6] Summary Form for Proposal 13859 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures BOA, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=6830.0, BUFFER-TIME=7277.0, EXTENDED=NO, FLASH=YES, FP-POS=3, FP-POS=ALL, SEGMENT=A ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PHASE 0.97014 TO 0.97473, Period 4.353011 D AND ZERO-PHASE HJD2455575.5136, SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, MIRRORA, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names WASP-13, WASP-18 ------------------------------------------------------------------------------------------------------------------------------------