14906( 2) - 20-Feb-2017 16:37:24 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14906 Version: 2 Check-in Time: 20-Feb-2017 16:37:24 STScI Edit Number: 0 Title UV irradiation of the Earth-sized planets orbiting TRAPPIST-1 ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Peter J. Wheatley The University of Warwick Y CoI: Mr. Tom Michael Louden The University of Warwick N CoI: Dr. Vincent Bourrier Observatoire de Geneve N CoI: Dr. David Ehrenreich Observatoire de Geneve N CoI: Dr. Michael Gillon Universite de Liege N CoI: Dr. Emeline Bolmont Universite de Namur N ------------------------------------------------------------------------------------ Abstract The remarkable discovery of a system of three Earth-sized potentially-habitable planets transiting the ultra-cool dwarf TRAPPIST-1 provides an unprecedented opportunity for detailed study of the atmospheres of terrestrial exoplanets. Our analysis of an archival XMM-Newton observation of the star revealed XUV radiation that was fifty times stronger than assumed in a theoretical study of the planetary atmospheres, with enough XUV irradiation to profoundly modify and perhaps entirely strip those atmospheres. Here we propose a longer XMM-Newton observation that will cover a full spin cycle of the star and more accurately define the XUV irradiation of the exoplanets. This is an essential step in assessing the habitability of these and similar exoplanets around ultra-cool dwarfs. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our goal is to detect high-excitation UV emission lines from the chromosphere and corona of the exoplanet host star TRAPPIST-1. This is a very late type M dwarf (M8) that is host to potentially-habitable Earth-sized exoplanets. A joint analysis with our coordinated XMM-Newton X-ray observation will allow us to reconstruct the complete extreme-ultraviolet spectrum of the star and hence the high-energy irradiation of the planets in this system. We are particularly interested in detecting the SiIV lines at 1394 and 1403A, and the CIV lines at 1550A. We can also hope to detect SiIII 1207A, OV 1218A and/or NV 1240A, although these are close to Lyman-alpha and may suffer contamination by airglow emission. In order to maximise our sensitivity away from airglow lines we select the relatively wide 0.5arcsec slit. Because we expect the lines to be weak and close to the detection limit, we also chose the D1 pseudo-aperture in order to minimise dark current in the detector. We request that our three orbits are scheduld as a single visit that is simultaneous with one of our XMM-Newton observations. This will avoid ambiguity in our analysis related to stellar variability. We have put the visit on hold 14906( 2) - 20-Feb-2017 16:37:24 - [ 2] awaiting the coordination of HST and XMM scheduling. The XMM program consists of a series of 3 visits, each lasting 12 hours, and separated by about 2 days. The XMM visits will be scheduled in coordination with HST in one of two visibility windows: either May/June 2017 (when we note the visibility for HST is poor) or in Nov/Dec 2017 (when the visibility for HST is good). ------------------------------------------------------------------------------------ 14906( 2) - 20-Feb-2017 16:37:24 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 TRAPPIST-1 STAR, M V-IV RA=23H06M30.3400S +/- 0.13", J2000 V = V = 18.80 +/- 0.08 R=16.47+-0.07, DEC=-05D02'36.44" +/- 0.13" -51.688 I=14.0+-0.1, J=11.35+-0.02, K=10.30+-0.02 Reference Frame: ICRS Extended: NO Comments: This position was measured using 2015 TRAPPIST images, and was used for the successful STIS obervations of programs 14493 and 14900. Radial velocity comes from Barnes et al. 2014 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.86 0.06171226415390873 -0.4719 0.08258 ------------------------------------------------------------------------------------------------------------------------------------ 14906( 2) - 20-Feb-2017 16:37:24 - [ 4] Visit: 01 (Trappist-1 FUV spectroscopy) Visit Requirements: ON HOLD On Hold Comments: The HST visit should be carried out simultaneously, or as close in time as possible, with one of the visits of our XMM program. The XMM program consists of a series of 3 visits, each lasting 12 hours, and separated by about 2 days. The XMM visits will be scheduled in coordination with HST in one of two visibility windows: either May/June 2017 (when we note the visibility for HST is poor) or in Nov/Dec 2017 (when the visibility for HST is good). 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 TRAPPIST-1 STIS/CCD ACQ F28X50LP MIRROR 1 5 S (5 S) Comments: The target has been acquired with STIS using the default setup before as part of HST program 14493, here we use the same parameters. ------------------------------------------------------------------------------------------------------------------------------------ 2 TRAPPIST-1 STIS/FUV TIME-TA 52X0.5D1 G140L 1425 BUFFER-TIME=500 1 2293 S -MAMA G (2293 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TRAPPIST-1 STIS/FUV TIME-TA 52X0.5D1 G140L 1425 BUFFER-TIME=500 1 2963 S -MAMA G (2963 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 TRAPPIST-1 STIS/FUV TIME-TA 52X0.5D1 G140L 1425 BUFFER-TIME=500 1 2921 S -MAMA G (2921 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 | ------------------------------------------------------------------------------------------------------------------------------------ TRAPPIST-1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TRAPPIST-1 2 STIS/FUV TIME-TA 52X0.5D1 G140L 1425 none none none none 1 N/A -MAMA G TRAPPIST-1 3 STIS/FUV TIME-TA 52X0.5D1 G140L 1425 none none none none 2 N/A -MAMA G TRAPPIST-1 4 STIS/FUV TIME-TA 52X0.5D1 G140L 1425 none none none none 3 N/A -MAMA G 14906( 2) - 20-Feb-2017 16:37:24 - [ 5] Summary Form for Proposal 14906 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.5D1, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=500 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ON HOLD ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names TRAPPIST-1 ------------------------------------------------------------------------------------------------------------------------------------