15699( 6) - 21-Nov-2019 16:28:10 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15699 Version: 6 Check-in Time: 21-Nov-2019 16:28:10 STScI Edit Number: 0 Title Pi Men c: The first confirmed water world? ------------------------------------------------------------------------------------ Type Cycle GO 26 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Antonio Garcia Munoz Technische Universitat Berlin Y CoI: Dr. Luca Fossati Space Research Institute, Austrian Academy N of Sciences CoI: Dr. Davide Gandolfi University of Torino N CoI: Juan Cabrera German Aerospace Center (DLR) N CoI: Prof. Heike Rauer Deutsches Zentrum fur Luft- und Raumfahrt N eV, IfP CoI: Dr. Allison Youngblood University of Colorado at Boulder N ------------------------------------------------------------------------------------ Abstract Planets with water-dominated bulk compositions are not represented in our Solar System. Their existence will have major implications on the theories of planet formation and evolution. Yet, none of the ~4, 000 known exoplanets have been definitely identified as a water world. Pi Men c, TESS's first discovery, probably stands the best chance to confirm the reality of water worlds. This super-Earth is strongly irradiated by its solar-type host star, and its bulk density is consistent with 50-100% by volume in H2O. Only 18 pc away, this bright system is ideal for transmission spectroscopy, especially at FUV wavelengths probing the uppermost atmosphere. Our photochemistry-evaporation models show that the stellar irradiation received by the planet sustains a vigorous atmospheric outflow. If H2O or other heavy molecules are present, they will photodissociate into atoms and form an extended upper atmosphere that can be probed through absorption at resonance lines. In many ways, Pi Men c is an optimal target for such an investigation. We request 10 HST orbits to cover two FUV transits and search for absorption by H I, O I and C II in the planet's upper atmosphere. Detecting these atoms will allow us to assess whether Pi Men c contains abundant H2O or other heavy gases (e.g. CO2 / CO), and will motivate a thorough observing programme in future GO Calls. This insight is unattainable by current facilities operating in the near-infrared. We will support our HST-based findings with comprehensive photochemical modeling of the planet's upper and lower atmospheres. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe two transits of pi Men c with 2 visits. 1 visit will entirely use STIS G140M 52"x0.2" (1222 cenwave; time-tag mode) to prioritize Lyman alpha (1216 Angstroms), and the other will entirely use COS G130M PSA (1222 cenwave; time-tag mode) to prioritize the metal lines. We will also be attempting an airglow subtraction on Lyman alpha in the COS spectra as was recently demonstrated in Bourrier et al. (2018), which would allow us to search for time variability in the planetary Lyman alpha absorption. The visits will each contain 5 consecutive orbits. The transit of pi Men c lasts approximately 3 15699( 6) - 21-Nov-2019 16:28:10 - [ 2] hours, so the first 2 orbits will cover the pre-transit period, the second 2 orbits will cover the transit, and the final orbit will cover the post-transit period. ------------------------------------------------------------------------------------ 15699( 6) - 21-Nov-2019 16:28:10 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PI-MEN EXT-STAR, EXTRA-SOLAR RA=05H37M9.8851S +/- 0.0640", J2000 V = V = 5.67 GALEX FUV = 17.52+/-0.06 mag PLANET, G V-IV DEC=-80D28'8.83" +/- 0.0671" 10.73 Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector 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 0.12529233931567293 1.048845 0.0547052 ------------------------------------------------------------------------------------------------------------------------------------ 15699( 6) - 21-Nov-2019 16:28:10 - [ 4] Visit: 01 (STIS visit) Visit Requirements: Period 6.2678216 D AND ZERO-PHASE HJD2458325.5032199 On Hold Comments: Additional Comments: As in past programs targeting Ly alpha exoplanet transits with STIS, we keep the instrument settings identical throughout the entire visit. We enabled the available wavecal=no mode to increase the duty cycle of the STIS observations and prevent auto-wave calibration from disrupting the transit time sequence in the STIS visit and preventing instrument setting changes. In addition, we keep an identical setup for the entire visit and do not switch between any settings to further prevent instrument-induced systematic errors in the photometric time series observations. For wavelength calibration, we set a wavelength calibration frame during the Earth occultation at the end of each orbit. 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 PI-MEN STIS/CCD ACQ F28X50OII MIRROR 1 1 S (1 S) PHASE 0.9645 TO 0.9710; I SEQ 1-3 NON-INT Comments: Acquisition based on the stellar V band magnitude and effective temperature. ------------------------------------------------------------------------------------------------------------------------------------ 2 PI-MEN STIS/FUV TIME-TA 52X0.2 G140M 1222 BUFFER-TIME=5276, WAVECAL=NO 1 2704 S -MAMA G see below (2644 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WAVE STIS/FUV ACCUM 52X0.2 G140M 1222 1 DEF (0 S) -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 4 PI-MEN STIS/FUV TIME-TA 52X0.2 G140M 1222 BUFFER-TIME=5276, WAVECAL=NO 1 3202 S SEQ 4-5 NON-INT -MAMA G (3202 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WAVE STIS/FUV ACCUM 52X0.2 G140M 1222 1 DEF (0 S) -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 6 PI-MEN STIS/FUV TIME-TA 52X0.2 G140M 1222 BUFFER-TIME=5276, WAVECAL=NO 1 3202 S SEQ 6-7 NON-INT -MAMA G (3202 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WAVE STIS/FUV ACCUM 52X0.2 G140M 1222 1 DEF (0 S) -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 8 PI-MEN STIS/FUV TIME-TA 52X0.2 G140M 1222 BUFFER-TIME=5276, WAVECAL=NO 1 3202 S SEQ 8-9 NON-INT -MAMA G (3202 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 WAVE STIS/FUV ACCUM 52X0.2 G140M 1222 1 DEF (0 S) -MAMA ------------------------------------------------------------------------------------------------------------------------------------ 10 PI-MEN STIS/FUV TIME-TA 52X0.2 G140M 1222 BUFFER-TIME=5276, WAVECAL=NO 1 3202 S SEQ 10-11 NON-INT -MAMA G (3202 S) ------------------------------------------------------------------------------------------------------------------------------------ 11 WAVE STIS/FUV ACCUM 52X0.2 G140M 1222 1 DEF (0 S) -MAMA 15699( 6) - 21-Nov-2019 16:28:10 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ PI-MEN 1 STIS/CCD ACQ F28X50OI MIRROR none none none none 1 N/A II PI-MEN 2 STIS/FUV TIME-TA 52X0.2 G140M 1222 none none none none 1 2644.0 S -MAMA G WAVE 3 STIS/FUV ACCUM 52X0.2 G140M 1222 none none none none 1 N/A -MAMA PI-MEN 4 STIS/FUV TIME-TA 52X0.2 G140M 1222 none none none none 2 N/A -MAMA G WAVE 5 STIS/FUV ACCUM 52X0.2 G140M 1222 none none none none 2 N/A -MAMA PI-MEN 6 STIS/FUV TIME-TA 52X0.2 G140M 1222 none none none none 3 N/A -MAMA G WAVE 7 STIS/FUV ACCUM 52X0.2 G140M 1222 none none none none 3 N/A -MAMA PI-MEN 8 STIS/FUV TIME-TA 52X0.2 G140M 1222 none none none none 4 N/A -MAMA G WAVE 9 STIS/FUV ACCUM 52X0.2 G140M 1222 none none none none 4 N/A -MAMA PI-MEN 10 STIS/FUV TIME-TA 52X0.2 G140M 1222 none none none none 5 N/A -MAMA G WAVE 11 STIS/FUV ACCUM 52X0.2 G140M 1222 none none none none 5 N/A -MAMA 15699( 6) - 21-Nov-2019 16:28:10 - [ 6] Visit: 02 (COS visit) Visit Requirements: Period 6.2678216 D AND ZERO-PHASE HJD2458325.5032199 On Hold Comments: Additional Comments: 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 PI-MEN COS/NUV ACQ/IMA BOA MIRRORB 1 47 S (47 PHASE 0.9640 TO 0.9705; GE S) SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 PI-MEN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=5527, FP-POS=3, 1 2842 S G FLASH=YES see below (2429 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 PI-MEN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=5527, FLASH=YES, 1 3168 S G FP-POS=3 (3168 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 PI-MEN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=5527, FLASH=YES, 1 3168 S G FP-POS=3 (3168 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 PI-MEN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=5527, FLASH=YES, 1 3168 S G FP-POS=3 (3168 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 PI-MEN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=5527, FLASH=YES, 1 1619 S G FP-POS=3 see below (3168 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 | ------------------------------------------------------------------------------------------------------------------------------------ PI-MEN 1 COS/NUV ACQ/IMA BOA MIRRORB none none none none 1 N/A GE PI-MEN 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 2429.0 S G PI-MEN 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G PI-MEN 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G PI-MEN 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 4 N/A G PI-MEN 6 COS/FUV TIME-TA PSA G130M 1291 none none none none 5 3168.0 S G 15699( 6) - 21-Nov-2019 16:28:10 - [ 7] Summary Form for Proposal 15699 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, BOA, F28X50OIII, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV, STIS/CCD, STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=5276, BUFFER-TIME=5527, FLASH=YES, FP-POS=3, WAVECAL=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PHASE 0.9640 TO 0.9705, PHASE 0.9645 TO 0.9710, Period 6.2678216 D AND ZERO-PHASE HJD2458325.5032199, SEQ 1-2 NON-INT, SEQ 1-3 NON-INT, SEQ 10-11 NON-INT, SEQ 4-5 NON-INT, SEQ 6-7 NON-INT, SEQ 8-9 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G140M, MIRROR, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names PI-MEN, WAVE ------------------------------------------------------------------------------------------------------------------------------------